Home

USER's GUIDE - Tornado Vortex lattice method

1. ETE TEE IE PE 11 Menu The main menu shows the available in Tornado Select 1 to get to the geometry setup menu Aircraft geometry setup 2 Flight state setup Move reference point origin Change rudder setting Processor access Post processing Result Plot functions Keyboard access About Release Info EXIT Please enter choice from above 1 Figure 25 Sample screen output 38 ETE TEE PE PE 11 1 Define New Geometry 2 Load Geometry 3 Edit current geometry 4 Save current geometry 0 Cancel Please enter choice from above 1 Number of Wings 1 LLELLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLE Dataregarding wing number 1 LELLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLE Number of semispanwise partitions 7 LELLLLLLLLLLLLLLLLLLLLLLLLLLLLELI Data regarding partition 1 Is wing mirrored in xz 1 0 Z NOTE Moment calculation will be done around the system origin Place main wing apex accordingly Apex x coord 0 Apex y coord 0 Apex z coord 0 Root chord 2 Bas
2. C mac COLLOC gamma lock S ref VORTEX Main Scalar reference span Scalar reference chord Matrix 3xnumber of panels containing the xyz coordinates for all collocation points Vector number of panels containing the vorticity of every vortex sling Vector lock variable for different calculations plots Matrix 3xnumber of panels containing the normals of every panel Scalar of reference area Matrix number of panelsx8x3 containing the xyz coordinates for all points on the vortex sling normally 8 or 6 The variables in Tornado s main function are alpha AS b betha Scalar angle of attack Scalar airspeed Matrix number of wings x number of partitions showing span of each partitions Scalar angle of sideslip Vector number of wings root chord of each wing 31 call dihed fc flapped fnx foil fsym Loop nelem nx ny nwing stat startx starty startz Scalar status variable Matrix number of wings x number of partitions showing dihedral of each partitions Matrix number of wings x number of partitions showing flap chord in parts of partitions chord Matrix number of wings x number of partitions showing if partition is flapped Matrix number of wings x number of partitions showing number of panels chordwise on each flap Matrix number of wings x number of partitions x 2 showing inner and outer airfoil of each partitio
3. From here you may reach all pre and post processing functions available in Tornado Geometry Menu From here you can choose to create a new geometry to edit a current geometry to load one from file or to save a geometry to file Main Processor Menu From here you may start the computations that Tornado does The simple calculation should be the primary option when trying out a new design Tornado Plotting Functions Menu From here the results from previously done calculations may be accessed as plots Program Execution The normal way of performing computations with Tornado is to 1 Define geometry either load one or create a new one 2 Define a flight condition either by loading one or creating a new one This is done in the Flight state setup menu 3 Perform a simple calculation in the processor menu 4 Review the results in the postprocessor menu using the Geometry plot option as well as the Solution plot simple state 5 Iterate change geometry or state and perform some sweep calculations 45
4. geometry of the wings and partitions calls geometry to do the panels 35 gplot inpt12 Intro Plots the geometry of the design figures 1 3 Input function to get all geometry variables Displays release info and startup screen lemmabatch Experimental function not used in Tornado but please examine main normals4 questions rplot further Current main function of Tornado Calculates the normals of each panel Most user interface questions are collected here Plots various results from a simple state solution setboundary3 Calculates the boundary conditions for each panel setrudder3 setupl12 slope solver4 solverloop specfun splot splot2 statesetup tarea tcros tedit terror tmesh tnorm Function that rotates flap coordinates around the hinge Not used Calculates the angle of normal rotation due to camber Calculates forces and moments of a design Loops over solver4 to provide different kinds of solutions Moves the geometry around in the xyz space Not used Plots results of a central difference expansion Plots results of sweep calculations Sets up the flight state Calculates the area of each panel Cross product calculation Edit geometry function Function to produce error messages Creates the panel cornerpoints Calculates length of a 3 d vector 36 tplot Menu function that calls the different plottingfunctions trot3 Rotates one vect
5. in geometry the flap 3 430 1 rad A pressure difference coefficient plot is also displayed which reveals the panel layout could be better The large gradient in pressure from wing to flap indicates that a larger number of panels should be used chord wise to get better more accurate results 42 References 1 Moran J Computational Fluid Dynamics Weily amp Sons 1984 2 Bertin J amp Smith M Aerodynamics for engineers 3rd Ed Prentice Hall 1998 43 License amp copyright information Tornado a Vortex lattice program for conceptual aircraft design Copyright C 2000 Tomas Melin This program is free software you can redistribute it and or modify it under the terms of the GNU General Public License as published by the Free Software Foundation either version 2 of the License or at your option any later version This program is distributed in the hope that it will be useful but WITHOUT ANY WARRANTY without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE See the GNU General Public License for more details You should have received a copy of the GNU General Public License along with this program if not write to the Free Software Foundation Inc 59 Temple Place Suite 330 Boston MA 02111 1307 USA The Author can be reached by Postal mail Tomas Melin Institutionen f r flygteknik Teknikringen 8 5 tr SE 100 44 Stockholm SWEDEN E mail t94_meu t kth se The
6. y if no dihedral is present Span of partition 5 gives tip to tip span of 10 as wing is symmetric in xz A taper of 1 means that the tip chord also is 2 meters Wing should be flat at the tip as well Sweep the wing c 4 line 45 degrees from the y axis No tip twist Trailing edge flap selected Selecting a flap chord of 2096 of the local chord One chord wise panel on the flap And the flaps should deflect symmetrically on both port and starboard side as they would if they where real flaps and not ailerons 39 Main menu as above Tornado plotting functions Clear plots Geometry plot Solution plot simple state Solution Central difference expansion Solution Alpha sweep Solution Beta sweep Solution Delta sweep Solution Roll speed sweep Solution Pitch speed sweep Solution yaw speed sweep 0 BACK Enter type of plot 2 3 D Wing configuration Wing y coord Wing x coord ETE TEE IE TE PE HE IT Input sequence for aircraft state CR 1 Define New State 2 Load State 0 Cancel Please enter choice from above Figure 25 continued Sample output After this input sequence we r
7. 2 Alpha sweep calculation Beta sweep calculation Delta sweep calculation Roll sweep calculation Pitch sweep calculation Yaw sweep calculation Central difference expansion around current state Cancel Please enter choice from above Figure 7 Main processor menu of Tornado The simple solution calculation will give you the zeroth order coefficients CL CD and so on for the entire design at the selected state Results are saved in the output file output fmcoeff mat you can also access them from the post processor menu The different sweep calculations will perform a series of simple calculations by varying the selected parameter alpha beta and saving the coefficients as vectors in the output file Example output Cx_alpha mat The parameter delta is flap deflection In this function you must also specify for which rudder to do the deflection sweep You can also get result plots from the post processor menu The central difference calculation option will launch a central difference calculation in order to get the first order derivatives of the coefficients Results are saved in the output fmfcoeff mat As before you can review the results directly in the post processor menu Rudder derivatives are stored as a vector in the same order as their corresponding rudders Post processing Result Plot functions In the post processor menu you can reach the solutions to each calculation done in the pr
8. 2 ee ee d que genere dte 7 Flightsst te Setup menus us s re eod teer 8 MOVE reference PUO RF RE EUR 8 Change rudder Setting x aen e RU e e 9 PrOCOSSOT QCCOSS res SH e RU PEU 9 Post processing Result Plot functions eene enne eene trente entren nnne 10 Keyboard se edu trat d RUE eme GU ie mera RE 10 About Release Ifo eee ea we deg ede dne rcd ipe 11 es Uu Eu UIDI A 11 lugo 12 en e PlOtS E 12 Simple solution ea tte Ht REGE 13 Central difference solution plots eee e eet 14 Sweep Plots ii oc RD de EP RN URDU VER UR ret Degree 15 OUTPUT P ES EE M EE 16 DESIGN FEATURE S 16 COSORDINATE SYSTEM va otn aite ne EIE tev 16 WING 16 WINGS eee niente eite bte Uaec tee oie E 16 PARTITIONS eei Uaec 16 PANELS eM EEE E 17 WING FEATURES A tetro to ete RI Eee 17 Apex coordinates o e a eate rr qt nacre ed aU e rus 18 x ss ERES qup aane duetumuquvoquee eaaet AU Uem eds 18 TOD pep ER E 18 SWeeD s asd Se eua E mme Su 19 Camber iie de te REESE Rute R eges e Os e AED 19 ak tee EIS dp RE RU EE e dete a ee est UR 20 Numbe
9. 2 or later Connect to the directory containing Tornado Start Tornado by typing Tornado and press enter Load a geometry Select option Aircraft geometry setup Select option load geometry Load the example file X 00 mat by typing 00 and press enter Load a state Select option flight state setup Select option load state Load the example file a5v10 mat by typing a5v10 and press enter Calculate a solution Select option Processor access Select option Simple solutions calculation View results Select option Post processor Select option Solution plot simple state User Interface Menu system Most functions in Tornado may be reached via text menus The menu that becomes visible directly at start up is the main menu Other menus are the flight state menu the solver menu and the result plot menu Navigate through the different menus enter the number of the row containing the desired command Tornado Main Menu TMM This version of Tornado is text based with a menu system From the Tornado main menu all of the essential functions in Tornado may be reached see fig 2 mnnm EET EHE E PEE EIE E PEE TORNADO Main Menu nnn Hn 1 Aircraft geometry setup 2 Flight state setup 3 Move reference point origin 4 Change rudder setting 5 Processor access 6 Post processing Result Plot functions 7 Keyboard access 9 A
10. ERR 40 Flight state Setup a sete e ert erede 40 T lie processor nete o sates tv ee 41 REFERENCES s cssssssssssssessssrsesscssssssessssessassssessessssessessssessassssessassssessesessessassssessesessessesessessesessessesessessessesers 43 LICENSE amp COPYRIGHT 44 TORNADO REFERENCE CARD DETACHABLE 45 Regarding this document Format Author Tomas Melin Title User s guide and reference manual for Tornado Publisher Royal Institute of Technology KTH Department of aeronautics Published 2000 12 Release information Substitutes the document User s guide to Tornado release 2 1 2000 10 same author Background This document is a part of the master thesis Vortex Lattice MATLAB Implementation for Linear Aerodynamic Wing Applications by Tomas Melin written at the Aerodynamics department during 1999 2000 This is the user s guide for the Matlab program Tornado which is part of the thesis and contains a description of the program Aim It is the aim of this document to provide a user s guide and a reference manual for Tornado The contents should give instructions on how to use and develop the program Also the inner structure of Tornado is explained and the course of program execution is shown Copyright information This document as well as the progr
11. Royal Institute of Technology KTH hereby disclaims all copyright interest in the program Tornado a vortex lattice program written by Tomas Melin 20 Dec 2000 Arthur Rizzi Prof 44 Tornado Reference Card Detachable TORNADO Main Menu M 0 En Aircraft geometry setup Flight state setup Move reference point origin Change rudder setting Processor access Post proccessing Result Plot functions Keyboard access About Release Info EXIT Please enter choice from above Geometry menu 1 Define New Geometry 2 Load Geometry 3 Edit current geometry 4 Save current geometry 0 Cancel Please enter choice from above ain Processor menu Simple solution calculation Forces Coe Alpha sweep calculation Beta sweep calculation Delta sweep calculation Roll sweep calculation Pitch sweep calculation Yaw sweep calculation Central difference expansion around current state Cancel ter choice from above please Tornado plotting functions 0 En Clear plots Geometry plot Solution plot simple state Solution Central difference expansion Solution Alpha sweep Solution Beta sweep Solution Delta sweep Solution Roll speed sweep Solution Pitch speed sweep 10 Solution yaw speed sweep BACK ter type of plot Shown to the left are the four most important menus of Tornado They are Main Menu
12. USER s GUIDE Reference manual TORNADO 1 0 RELEASE 2 3 2001 01 31 ane at EY REGARDING THIS DOCUMENT sscssssssssssessessrssssssssesscssssessessssessesessessessssessessssessessesessesessessesessessesessesees 4 FORMAT 4 BACKGROUND 4 4 COPYRIGHT INFORMATION 4 INTRODUCTION TO TORNADO 4 THEPBROGRAM oun 4 bz MP 5 Applications uia ett EH EAR FEBR PEERS EUR E REA EOD ESSENT PERI 5 Gn E M 6 QUICK START eti enii A AANEEN EENEN SAEED ENEA EREKE EEEE E EEE iE 6 15 COO E HET aereis 6 Start oc e Re RE ERR XE HN HRERS cT E EEA EA SEE E E ES 6 d geometry eee p E DR EGER RI p RE a EROR a epe edi ere et 6 TOAD Slate sivo t RO RU Re SERERE Re ER 6 Calculate a solution a e rin E INE REPE PO eae n gr eu eee ud 6 TUI EE EM 6 USER INTERFACE 7 MENUSYS TEM a A Taa LRA IE Ree etur Tete 7 Tornado Main Men pean cee 7 Aircraft geometry Setup MENU
13. aircraft geometry together with the wake to accommodate the new position of origin The move reference point menu is shown in figure 5 This change cannot be saved to file For a permanent modification use the edit geometry option in the geometry menu to move the wing apex and then save to file RR Move reference point 1 Move reference point in x 2 Move reference point in y 3 Move reference point in Z 0 Cancel Please enter choice from above Figure 5 The Move reference point menu Change setting The change rudder setting menu will allow change of deflection of flaps ailerons elevators and other trailing edge control surfaces Keep in mind that all deflecting surfaces are called flaps in Tornado and that they are numbered in the order that they where created The Change rudder setting menu option will not start a sub menu but rather just ask two questions as shown in figure 6 Change rudder setting 1 New control deflection deg Figure 6 The change rudder setting questions as asked in Tornado Processor access This menu option will open the main solver submenu From here you may choose different forms of solutions See figure 7 Processor menu 1 Simple solution calculation only
14. am Tornado is distributed according to the GNU Open license protocol Introduction to Tornado The program Tornado is a 3D vortex lattice program with flexible wake It may be used for a variety of tasks that require the Tornado s output These outputs are 3D forces acting on each panel aerodynamic coefficients in both body and wind axis Stability derivatives with respect to angle of attack angle of sideslip angular rates and rudder deflections In order to be easily ported Tornado is written in Matlab The required Matlab version is 5 3 Tornado works on any Matlab supporting platforms It has been tested for win95 win98 NT4 Solaris and Mac OS Tornado is an open source program according to GNU Methods Tornado is based on standard vortex lattice theory stemming from potential flow theory The wake coming off the trailing edge of every lifting surface is flexible and changes shape according to the flight condition For example a rolling aircraft will have a cork screw shaped wake which will influence the aerodynamic coefficients The classical horse shoe arrangement of other vortex lattice programs has been replaced with a vortex sling arrangement It basically works in the same way as the horse shoe procedure with the exception that the legs of the shoe are flexible and consist of seven instead of three vortices of equal strength This is shown in figure 1 Vortex sling on a Horse shoe on panel wi
15. aused by panel forces Cp Panel coefficient of pressure matrix fmfcoeff m contains the variables from the central difference calculation CCP CD b CX R CZ P CC CD d CX a CZ CC R CL P CX b CZ CC a CL Q CX d CZa CC b CL R CY P CZ b CC d CL a CY Q CZ d CD P CL b CY R CD Q CL d CY a CIQ CD_R CX_P CY_b CIR CD CX Q CY d The first letter C stands for coefficient Cl b Cm P Cm Cm R Cm a Cm b Cm d Cn P Cn Cn R Cn a Cn b Cn d The second letter stands for the coefficient involved see fmcoeff m The third letter stands for the derivative in question a for alpha b for beta d for delta rudder vector P for roll speed Q for pitch speed R for yaw speed Cx alpha m Contains vectors describing a coefficient at different values of alpha alpha itself is stored in the vector affa Vectors CL fa CD fa CCfa Cmfa Cnfa CL as function of alpha CD as function of alpha CC as function of alpha Cl as function of alpha Cm as function of alpha Cn as function of alpha 30 Variables CX fa CZfa Affa CX as function of alpha CY as function of alpha CZ as function of alpha The vector containing the different values of alpha The other output files Cx parameter contains the coefficients as a function of the parameter used in its name just like Cx alpha Global The global variables in Tornado are b ref
16. bout Release Info 0 EXIT Please enter choice from above Figure 2 Tornado Main Menu Aircraft geometry setup menu From the Aircraft geometry setup menu you may select to create a new geometry design to load a geometry from file to save a geometry to file or to edit a geometry currently in memory The aircraft geometry setup is shown in figure 3 1 Define New Geometry 2 Load Geometry 3 Edit current geometry 4 Save current geometry 0 Cancel Please enter choice from above Figure 3 Aircraft geometry setup menu Flight state setup menu In the flight state setup menu you may select to create a new state to load a state from file or to save a state to file The state is the flight condition with angle of attack angle of sideslip rotational angular rates and true airspeed The flight state menu is shown in figure 4 Input sequence for aircraft state 1 Define New State 2 Load State 0 Cancel Please enter choice from above Figure 4 Flight state menu as shown in Tornado Move reference point When selecting the menu choice Move reference point you will be transferred into the submenu for moving the reference point N B The reference point in Tornado is always the system origin 0 0 0 Thus moving the reference point will actually move the entire
17. d a figure with six subplots Each of these subplots will show a coefficient as a function of the selected sweep parameter An example of a sweep plot is shown in figure 12 Coefficient dependency on alpha 0 05 Alpha rad 0 05 Alpha rad 0 05 Alpha rad 0 05 Alpha rad Figure 12 Solutions plot of an alpha sweep calculation Jagged curves are due to large magnification 0 05 Alpha rad 0 05 Alpha rad 15 Output files Tornado will produce a number of files containing the output from the different kinds of calculations Regarding the contents of these files please see the chapter on data structures The output files are located in the output directory and they are ac mat A copy of the geometry used for the last solution fmcoeff mat Results of a simple state calculation Fmfcoeff mat Results of a central difference expansion Cx alpha mat Results of an alpha sweep The other sweep results follow the same pattern and are called Cx beta Cx P and so on Design features Co ordinate system Tornado uses a Cartesian coordinate system with the X axis along the aircraft body increasing aft The Y axis is aligned positive out through the starboard wing when no dihedral is present The Z axis is right hand perpendicular to the X and Y axis Le positive upwards When dihedral is 90 degrees for a fin the span is fully aligned in the Z positive direc
18. e chord airfoil nr 0 Wing dihedral deg 0 Number of vortices chordwise 1 Number of vortices semispanwise 4 Span of partition 5 Taper ratio 1 Outboard airfoil nr 0 1 4 Chord line Sweep deg 45 Outboard 1 4 Chord twist deg 0 Is partition flapped 1 0 7 Flap chord in parts of root chord 0 1 0 2 Number of chordwise vortices on flap 1 Does control deflect symmetrically 1 0 1 Figure 25 continued Sample output The Geometry menu In the geometry menu select the option Define new geometry In this sample case we want to look at a simple wing We start by defining the number of wings one lt Number of wings selected lt A loop regarding input for the first and in this case only wing starts here lt Since it s a simple wing we only need one partition selected here lt A loop outwards on the first wing starts here In this case we only have one partition hence it isn t really a loop The wing should be mirrored in the xz plane i e we want a port and a starboard wing Here you define the apex point of the wing the origin works fine More advanced users might want to put the apex x coordinate in 0 25 for a wing with a root chord of 1 Doing this would make all moments to be calculated around the c 4 point Root chord 2 international units meters Flat plate gives airfoil 0 Dihedral set to zero Number of vortices equals number of panels Chordwise x spanwise
19. e current version of Tornado the panels are evenly distributed on the partitions For reference panels are numbered from the leading edge backwards in row by row outwards See figure 13 3 D Wing configuration Wing y coord 1 0 5 Wing x coord Figure 13 Panel layout for a one partition wing Three panel chord wise and three panels semi spanwise Wing features Each wing has special features which define the shape of the wing During the geometry setup these are the inputs needed for each partition Apex coordinates Span Taper Sweep Camber Dihedral Twist Symmetry Root chord One per wing Flaps Flap symmetry If flap is present Flap chord in parts of root chord If flap is present Number of panels in chord X direction Number of panels in span Y direction Number of panels on the flap If flap is present Apex coordinates For each wing the apex coordinates have to be specified The apex is located at the first partition root chord leading edge It is important to know that all moments are calculated around the system origin 0 0 0 so that the main wing apex is placed accordingly most often in 0 25 0 0 if the root chord is 1 Span The span you are required to enter is the semispan of the partition in question i e the distance from the innermost to the outermost part of the partition The sum of the semispans of the partitions is the semispan of the entire wing S
20. ee figure 14 for details Second partition semi span Wing semi span First partition semi span Wing span amp Reference span b ref Figure 14 The semispans of the partitions and the wing Taper The taper or taper ratio is defined for each partition as follows T C outer 1 C inner where c is the local chord of the partitions Figure 13 above has a taper ratio of 0 5 which is visible in the picture Sweep The sweep of the partition is defined for the quarter chord line see figure 15 The sweep is the angle between the quarter chord line and the Y axis 3 D Wing configuration 9 Wing x coord Figure 15 Sweep of division is 0 degrees the quarter chord line is perpendicular to the Y axis Camber The camber lines currently available are taken from the NACA XXXX series For the first partition of a wing both inner and outer camber must be specified For subsequent partitions only the outer camber is needed Note for advanced users The slope is calculated in the function slope m To use other airfoils this is the function to edit Dihedral The dihedral is the angle between the X Y plane and the quarter chord line see figure 16 Currently only one dihedral angle per wing is possible For multiple dihedral wings please use more than one wing and set the outer wing apex to fit with the inner wing tip 3 D Wi
21. es Input files to Tornado are the geometry files containing the aircraft design and the state files containing the description of the flight state None of these are needed to run Tornado the first time but exist so that you may save and retrieve complex designs from disc The variables of the input files are listed below When using the standalone function diffbatch m you are required to specify the files needed in the computation Diffbatch m performs the central difference calculation in batch mode Output files A number of output files are produced by the different calculations possible in Tornado s main processor They are all saved in the output directory They are fmcoeff m from simple solution fmfcoeff m central difference Cx alpha m from alpha sweep calculation Cx beta m from beta sweep calculation Cx P m from roll angular rate sweep calculation Cx Q m from pitch angular rate sweep calculation Cx R m from yaw angular rate calculation Fmcoeff m contains the variables Scalars L Lift D Induced drag C Side force CL Lift coefficient CD Induced drag coefficient CC Side force coefficient CX X force CY Y force CZ Z force CI Roll moment coefficient 29 Pitch moment coefficient Cn Yaw moment coefficient Vectors F Body force vector M Body moment vector Matrices FORCE Panel force vector Force on each panel MOMENTS Panel moment vector Moments on origin c
22. etry Otherwise all points within the design s hull which are not part of the geometry e g area between wing and stabilizer will be displayed with an interpolated vorticity Plot number seven will present calculation results as hard numbers These are loaded from the output file fmcoeff m where more data is available An example of the plot is shown in figure 11 TORNADO CALACULATION RESULTS Reference area 3 Reference span Reference chord 1 Net Wind forces Lift Drag Side 66 1459 3 7302 1 3687e 015 Net Body forces Z X Y 66 2193 2 0489 1 3687e 015 CL 0 35998 0 36038 0 21026 0 020301 0 011151 5 2632 019 7 4487 018 7 4487 018 3 8518 018 alpha beta Airspeed Figure 11 Text output for a simple solution in Tornado plot 7 Central difference solution plots After a central difference expansion calculation is made the results may be viewed in the post processor The results are presented in two figures containing text The first one plot number 8 shows the stability derivatives with respect to the different state variables The second one plot number 9 shows the rudder derivatives 14 Sweep plots When a sweep calculation has been performed in the processor access menu results can be reviewed using the Solution Alpha sweep or any other type of sweep that has been performed from the post processor of the sweep plots will yiel
23. eturn to the Main menu To be sure that the geometry looks the way we want it we should plot it This is done via the post processor menu option 6 Select option 6 in the Main menu Post processor Selecting plot option number 2 will plot the geometry stored in memory The plot to the left shows the aircraft geometry as plotted from the postprocessor plot geometry option When the plotting functions have finished drawing the figures we should be back in the main menu Since the geometry looked as we wanted we can continue to the calculations Flight state setup Before completing any calculations we must select a flight condition or flight state as it is called in Tornado Go to the flight state setup menu in Tornado by selection option number 2 in the main menu In the flight state setup menu select option number 1 to define a new state 40 Six inputs are needed to define flight condition Enter the numbers in degrees or degrees per second Tornado uses radians internally and your input number will be converted automatically Alpha deg 5 Beta deg 0 Roll angular velocity deg s 0 Pitch angular velocity deg s 0 Yaw angular velocity deg s 0 True airspeed m s 10 RR TETAI TETEIEITETEIETEIEIEIETEIETETETETEIETEIETETEIETETETETETETETETETETELELETEIEL When you have defined the state you ll be asked if 1 Save data then go 5 you want to save these settings for f
24. ex x coordinate of each wing Vector number of wings showing apex y coordinate of each wing Vector number of wings showing apex z coordinate of each wing Matrix number of wings x number of partitions showing sweep of each partition In radians 34 symmetric Vector number of wings showing symmetry state Boolean 1 or 0 of each wing T Matrix number of wings x number of partitions showing taper of each partition TW Matrix number of wings x number of partitions x 2 showing inner and outer twist of each partition inner first Flight condition variables These are the variables needed in a state file alpha Scalar angle of attack AS Scalar airspeed betha Scalar angle of sideslip P Scalar roll angular rate Q Scalar pitch angular rate Scalar yaw angular rate Function files config cutline diffbatch 15 drawhinge geometry17 geosetup 14 Configuration function for different variables i e using other than standard S_ref Not used For debugging only A batch program taking the filename of an aircraft geometry file and a state file as input Producing a central difference expansion Function calculating the aerodynamic influence of every vortex sling on every panel Calculates the forward corners of a flap and draws a line in between the hinge line Calculates the corner points vortex points normals and collocation points of each panel Calculates the
25. g x coord Figure 22 Resulting geometry from inputs in figure 21 Saving a model To save a geometry design select option Save current geometry in the GSM A list of files of previously saved designs will be displayed as you are prompted for a file name for your new design aircraft designs are saved in the subdirectory aircraft 26 Restoring a saved model To load a previously saved model select Load Geometry in the GSM A list of files of the contents of the aircraft directory will be displayed as you are prompted for the filename of the file to load Editing a model To edit a model choose the option Edit current geometry This will work only if a geometry is loaded in the memory In the geometry editor menu you may choose to add or remove wings or partitions or to edit the features of one or more partitions State setup Creating a model The state model is less complex than the geometric model The state model consists of six variables Alpha beta roll pitch and yaw angular rates as well as airspeed To create a new state model you must have a defined geometry onto which the state model should be applied Select the state setup option in the main menu continue with the new state option Enter the state model parameters as you are prompted for them Saving a model In the state menu select Save State The state model will be saved as mat file in the data directory Res
26. gure 17 Double wing design with three flaps control surfaces Flap symmetry If flap is present and wing symmetry is set If symmetry for the wing is enabled you will be asked if the flap should be deflected symmetrically i e both starboard and port flap down at the same time The flap symmetry is a Boolean operator and should be true for flaps and elevators but false for ailerons See figure18 3 D Wing configuration Wing z coord 0 Wing x coord Wing y coord Figure 18 Asymmetrical flap deflected 20 degrees Flap chord fraction of local wing chord If flap is present To define the flap chord you should enter which fraction of the local wing chord is allocated to the flap Valid inputs are in the range 0 to 1 See figure 19 Figure 19 Flap with chord being 0 25 of the local chord Number of panels in chord X direction The number of panels in the chord direction will only have to be specified for the first partition of a wing Every subsequent partition will have the same number of panels Note to advanced users It is possible to change this value for subsequent partitions of a wing To do so use the Edit function in the geometry menu Select the wing and partition to change and select change nx Number of panels in span Y direction For each partition the number of panels in the span direction must be specified Number of panels on the flap If flap is present If a flap i
27. lots Geometry plots When you select the option draw geometry in the postprocessor menu Tornado will draw three plots The first plot is a 2D plot of the planform with layout of wings partitions and panels This figure is drawn in the XY plane The second plot shows planform layout in 3D The Rotate3D function is enabled so you can grab the figure and rotate it This plot will also show the collocation points of the panels with the panel normals drawn as dashed lines The third plot shows the panel layout with the trailing vortices visible of these plots are shown in figure 9 9 o Wing y coord Wing x coord 3 D Wing configuration Wing z coord Wing y coord Simple solution plots The Solution plot simple state option in the post processor menu will when selected yield plots 4 to 7 Plot number four displays the delta cp distribution across the aircraft A colour bar indicates the values An example is shown in figure 10 Delta cp distribution Figure 10 Delta cp distribution on wing alpha 5 degrees Plot number five shows the panel force s Z component displayed as an arrow on each panel As the arrow starts in the xy plane this plot is the clearest for designs with moderate dihedral Plot number six shows the wing vorticity as an elevated surface above the planform This plot will only be useful or accurate if you have a hull geom
28. lution plot simple state Solution Central difference expansion Solution Alpha sweep Solution Beta sweep Solution Delta sweep Solution Roll speed sweep Solution Pitch speed sweep 0 BACK Enter type of plot 3 TORNADO CALACULATION RESULTS Reference area 20 Reference span 10 Reference chord 1 Net Wind forces Lift Drag Side 366 7046 5 9897 9 4369e 016 Net Body forces Z X Y 365 8312 25 9935 9 4369e 016 0 29935 0 29864 0 88124 0 0048896 0 021219 Cn 9 9693e 019 7 7036 019 7 7036 019 2 0301 018 STATE alpha beta Airspeed Delta cp distribution Figure 25 continued Sample output Selecting option 3 in the post processor menu yields a couple of plots one being forces in Newton in both wind and body axis Coefficients of forces and moments are also represented A glance at the pitching moment reveals a large nose down moment This is because the reference point is located in the origin where we put the apex A better location of the apex should be somewhere at x 1 or 2 Having a look at CL which equals 0 29935 for an alpha of five degrees one could easily calculate the liftslope CL_a Knowing that the CL at alpha 0 also should be zero flat plate wing the lift slope should be GL 580 There is a difference in the liftslope calculated here and the liftslope calculated in Bertin amp Smith 2 3 443 but then again there is a slight difference
29. n inner first Matrix number of wings x number of partitions showing if flaps deflect symmetrically Scalar status variable Vector number of wings number of partitions per wing Matrix number of wings x number of partitions showing number of panels chordwise Matrix number of wings x number of partitions showing number of panels spanwise Scalar number of wings Scalar roll angular rate Scalar pitch angular rate Scalar yaw angular rate Scalar status variable Vector number of wings showing apex x coordinate of each wing Vector number of wings showing apex y coordinate of each wing Vector number of wings showing apex z coordinate of each wing 32 SW Matrix number of wings x number of partitions showing sweep of each partition symmetric Vector number of wings showing symmetric state 1 or 0 of each wing T Matrix number of wings x number of partitions showing taper of each partition TW Matrix number of wings x number of partitions x 2 showing inner and outer twist of each partitions inner first void Scalar status variable XYZ Matrix number of panels x 5 x 3 showing xyz coordinates for every corner of each panel Input variables of these are variables in Toprnados main function Some are needed to create a geometry and these are saved in the geometry input files in the aircraft directory They are b Matrix number of wings x number of partitions showi
30. n ro eco db ERR 27 Editing ai m del 27 STATE SETUPS ES 27 Creating d ecd a eee i dei rin o a HE vU RU 27 Saving aie d WI RO qi UR a EET P RE ERU UNO EUER D QI 27 Restoring saved ca EE E D Qe NER UE TE EXE PR b 27 CHANGE CONTROL SURFACE SETTING 27 Specifying control surface i e e RU t e e EH 27 Ium 27 PROGRAM EXECUTION 28 DATA STRUCTURES 29 PILES p 29 Inp t E SEEE 29 Output Tess een ee eons 29 MENGE ARIDAM 31 Glob l aunque 31 31 Input variables est 33 Flight condition variables eei ee t pire HE e e 35 FUNCTION FILES tertie TOR Dee PD TTD YR eerie 35 SAMPLE 38 AT NEMPE EE 38 The fal mens iesu te exe ty erri 38 The Geometry aa a 39 POS pEOGOSSOT see eee etie
31. ne Wing with two partition sweep 10 partitions sweeps 0 deg taper 0 5 and 20 degs taper 0 5 on both divisions Figure 20 Wing and semi spanwise partitions When the number of partitions for the current wing has been supplied the sequence with input of wing features for the first partition is started When all partitions for the current wing have been defined the input sequence turns to the next wing where the procedure is repeated A typical input sequence for a one wing one partition design is shown in figure 21 The resulting geometry is shown in figure 22 25 IK IK IR IK KI KIRK IK IK IA RK Data regarding wing number 1 HIRI RIK IK KIKI KK IK IK IK IK He e IK IR IA IA RK Number of semispanwise divisions 1 JESSE ESOS CSS IACI ISIE Data regarding division1 Is wing mirrored in xz 1 0 1 Apex x coord 0 Apex y coord 0 Apex z coord 0 Root chord 1 Base chord airfoil nr 0 Wing dihedral deg 0 Number of vortices chordwise 3 Number of vortices semispanwise 4 Span of division 2 Taper ratio 5 Outboard airfoil nr 0 1 4 Chord line Sweep deg 20 Outboard 1 4 Chord twist deg 0 Is division flapped 1 0 1 Flap chord in parts of root chord 0 1 0 2 Number of chordwise vorticies on flap 2 Does control deflect symetrically 1 0 1 Figure 21 Typical input sequence for a wing partition 3 D Wing configuration Wing y coord W in
32. ng configuration v o Wing Figure 16 Dihedral is 15 degrees panel normals are the eight unit length lines Twist The partition twist is defined as the angle between the tip chord of the partition and the root chord of the main wing The first wing entered For every additional wing the root twist has to be entered as well as the tip twist Symmetry The symmetry option is a Boolean operator which when set as true mirrors the wing in the XZ plane When editing geometry true 1 false 20 Usually symmetry should be set for main wing and stabiliser but not for the fin Root chord One per wing The root chord has to be entered for each wing For a multiple partition wing every additional partition after the first will have their root chords defined by the first partition root chord and taper ratio see section on taper This is done automatically 20 Wing number 1 Control surface number 1 Flap Control surface number 2 Aileron Wing number 2 Stabilizer Control surface number 3 Elevator Flaps The flap option is a Boolean operator when this is enabled the whole trailing edge of the partition is assumed to be a control surface It is possible to have more than one flap per wing but this requires that the wing contain at least as many partitions as flaps The flaps are numbered in the order they are defined see figure 17 Fi
33. ng span of each partitions Figure 24 shows the layout of the b matrix which is representative for all geometry matrices m T figure 24 Span matrix layout 33 dihed fc flapped fnx foil fsym nelem nx ny nwing startx starty startz SW Vector number of wings root chord of each wing Matrix number of wings x number of partitions showing dihedral of each partition In the current release 1 10 of Tornado the dihedral must be constant along the entire wing Matrix number of wings x number of partitions showing flap chord in part of the local partition chord Matrix number of wings x number of partitions showing if partition 15 flapped Boolean 1 or 0 Matrix number of wings x number of partitions showing number of panels chord wise on each flap Matrix number of wings x number of partitions x 2 showing inner and outer airfoil of each partition inner first Tornado release 1 10 supports flat and NACA four digits chamber lines Matrix number of wings x number of partitions showing if flaps deflect symmetrically Boolean Vector number of wings number of partitions per wing Matrix number of wings x number of partitions showing number of panels chordwise Matrix number of wings x number of partitions showing number of panels spanwise Scalar number of wings Vector number of wings showing ap
34. noted as and should be entered in rad s Yaw angular rate The yaw angular rate is the angular velocity around the Z axis It is denoted as and should be entered in rad s Air speed The air speed is needed to calculate forces and moments It is denoted AS and should be entered in meters second Geometry setup Creating a model The creation of a new aircraft model is initiated by selecting create new geometry in the geometry menu This will initiate a sequence of questions regarding the geometry of the new aircraft First the number of wings in the new design should be entered Wing in this context means every coherent surface producing lift e g main wing stabiliser or vertical fin For a GA aircraft these three would constitute the 3 wings to enter For each wing the input of necessary wing features will be requested This will be done in a nested loop one partition after another running down each wing Please see the wing features chapter for reference to these inputs 24 For each wing number of semispanwise partitions should entered The semispanwise partition is a subdivision of the entire wing Basically more than one partition should always be used if the wing is cranked or wing properties taper sweep etc are changed along wing s span A sketch of the wing and the wing partition is supplied as figure 20 Important partitions are numbered running outboard Wing with o
35. ocessor menu However since results are saved to file after each calculation a lock variable will stop you from plotting old results from previous calculations To be on the safe side you may want to delete all files in the output directory when starting a new design The post processor menu is shown in figure 8 TETTE PEE T Tornado plotting functions 1 Clear plots Geometry plot Solution plot simple state Solution Central difference expansion Solution Alpha sweep Solution Beta sweep Solution Delta sweep Solution Roll speed sweep Solution Pitch speed sweep Solution Yaw speed sweep 0 BACK Enter type of plot Figure 8 The post processor menu of Tornado Keyboard access Selecting the keyboard access option will give you a gt gt prompt in the workspace this might come in handy if you want to check some variables during execution Return to the Tornado main menu by typing return and press enter About Release Info The about release info menu option will when selected give you the release info with changes in design since the last update EXIT Terminates Tornado some variables will remain in memory so be sure to clear these if running your own modules afterwards If you have run the solver the result variables will be available in the output directory and are called mat files P
36. or around another used in drawhinge wakeplot Plots the wake in a geometry plot not currently used debugging function wakesetup2 Calculates the shape of the wake 37 sample matlab Sample Run Figure 25 shows the screen output from a lt MATLAB gt sample run of Tornado The planform Copyright 1984 1999 The MathWorks Inc comes from Bertin and Smith 2 Version 5 3 0 10183 R11 Jan 21 1999 Starting up In a standard program execution Matlab T t started t f these helpwin helpdesk or d Hu Pro ox SPEED 5 3 should be started in the normal way product information type tour or visit www mathworks com Start Matlab in the directory where the gt gt Tornado files reside gt gt program start NN hhh hhh hhh 28 3k a Start Tornado by typing Tornado then press enter First some release and copyright information will be shown before the Tornado main menu is displayed Welcome to Tornado 1 0 by Tomas Melin Copyright 1999 2000 LELLLLLLLLLLLLLLLLLLLLLLDLLLLLLLLLLLLLLDLLLLLLLLLLLLLLI x X gt Release 1 10 Beta 2000 10 02 Fixes since last revision divisions change name to partitions for better clarity 0X x X xo X X Bug in setrudder fixed for multiple wing AC
37. r of panels in chord X direction nennen een eene etre 22 Number of panels in span Y direction r o EEE tnnt nennen nee enne enne 22 Number of panels on the flap If flap is 22 REFERENCE UNITS eri PU e ette reete 23 CPG tese a i mede oot TAA 23 23 THE STATE 23 cai p i Ee Pee e ii p eorr eite tee tete 23 Angle attaCk asia S tet p He E c Eta ette de RO ee RHET EROR 23 of b Rt RH oaea eaae Sa ORE RO P EEAS Ee EEE Eig 23 rate det E RU eC pee ue een 23 PUGH GN SULA Suh a e EHE EI d D RD REIHE Hee De EHE aR 24 angular teet cas deo IH ettet e ded piece epi ee b poe e te ted 24 Air Speed isis asus cie oti e OR OO PRI D PAE EO eSa ESETE PESER TEREE 24 KAOOSEWUMOnQ 24 GEOMETRY SETUP i nr ERE ER EE EEE eA ERES ELE 24 Creating a model aee t ORO QU ER RE EET ERR 24 Saving GINO S 26 Restoring saved model a eb t e LO re a RO a ER Ue revere
38. s present the number of panels in the chord direction of the flap must be specified 22 Reference units The state model There are three reference units used in Tornado They are automatically calculated during the geometry setup If you want to use any other value you must edit the file config m in which instructions for this are included Name Dimension S ref L 2 c mac L b_ref L 5 Reference area is by default sum of areas of all panels on first wing The first defined wing considered to be the main wing of the design c mac Mean aerodynamic chord is by default the area weighed average mean aerodynamic chord of each partition on the main wing b ref The sum of partition semi spans of the main wing and twice this value if the wing is mirrored in the XZ plane State model features Angle of attack The angle of attack is defined as the angle of the oncoming air stream and the main wing root chord in the XZ plane By convention it is denoted alpha Angle of sideslip The angle of sideslip is defined as the angle of the oncoming air stream and the main wing root chord in the XY plane By convention it is denoted beta Roll angular rate The roll angular rate is the angular velocity around the X axis It is denoted as and should be entered in rad s 23 Tornado functions Pitch angular rate The pitch angular rate is the angular velocity around the Y axis It 15 de
39. th flap ordinary panel Figure 1 The seven segment vortex sling vs the horse shoe The source of the basic theory for the vortex lattice method used in Tornado has been the book Computational Fluid Dynamics by Moran 1 To calculate the first order derivatives Tornado performs a central difference calculation using the pre selected state and disturbing it by a small amount usually 0 5 degrees With the distorting wake non linear effects will be visible in some designs especially in those where main wing stabiliser interactions are important Applications Tornado is meant to be used primarily in the conceptual design stage of aircraft construction or in training and education Tornado supports multi wing designs with swept tapered cambered twisted and cranked wings with or without dihedral Any number of wings may be utilised as well as any number of control surfaces Canards flaps ailerons elevators and rudders may be employed Winglets fences and engine mounts may also be incorporated in the design Quick start How to Cautions One of the primary assumptions in the vortex lattice theory is the small angle of attack Therefore caution is advised when examining large angles as well as large rotational speeds No consideration is taken to fuselage effects or to any friction drag Compressibility effects are neglected as are thickness effects of the lifting surfaces Start Tornado Start Matlab version 4
40. tion Main wing reference The first wing entered is considered to be the main wing The root chord of the main wing defines the direction of the X axis Wings In TORNADO every flat surface is considered as a wing this means that there are no differences in input or calculation between main wing stabiliser or fin To create both starboard and the port sides of the main wing tick wing is mirrored Do the same for the stabiliser As for the fin don t use the symmetry setting but set the dihedral angle to 90 degrees This procedure will give you one wing half with its span directed in the Z direction Partitions Every lifting surface such as wing fin and so on is composed of a number of partitions The simplest wing contains only one partition while a more complex one may have five or more In each partition the wing design features are constant Examples are sweep and taper ratio Exceptions are twist and camber which have to be defined with inner and outer values for the first partition of a wing Succeeding partitions take on the outer feature of the previous element as their inner feature to assure continuity along the wing s span Thereby elements are numbered outwards Panels The panels are the small four corned elements that build up each partition No special input is needed to define their shape as this is auto generated once the number of panels in the chord wise and span wise directions have been entered In th
41. toring a saved model In the state menu select load state A list of previously defined state models is shown Change control surface setting Specifying control surface Control surfaces are numbered running outboard beginning with the first wing normally main wing For a GA design the first control surface would be the flaps the second the ailerons the third either rudder or elevator depending on if the fin was defined before the stabiliser or not Deflection Input control surface deflection is in degrees hinge lines are located at the leading edge of the rudder Hinge lines run outboard and the deflection is defined right hand positive for the starboard wing The port side deflection is also defined in the same way if 27 rudder deflection symmetry is not selected and the opposite if rudder deflection symmetry is selected i e both flaps deflect downwards Program execution chart Figure 23 shows the execution chart of Tornado The main function is invoked using the command tornado Every tab shows a deeper function layer main m questions m inpt12 m questions m tedit m geosetup14 m gplot m geosetup14 m statesetup m wakesetup2 m specfun m setrudder m Trot m Solverloop m Solver4 m Dnwash m Tcros m Tnorm m Setboundary m Setrudder m Trot m Tplot m Gplot m Rplot m Splotl m Splot2 m Copyright m Intro m Figure 23 Tornado execution chart Data structures Files Input fil
42. uture use not 2 Just go Please enter choice from above 2 We choose just go option Main menu as before Now we back in main menu and can start performing some calculations Select option 5 for processor access ETE TEE EIE P 11 Main Processor menu The processor The processor menu shows the different options Simple solution calculation Forces Coefficients only regarding calculation types Alpha sweep calculation Beta sweep calculation Delta sweep calculation Roll sweep calculation Pitch sweep calculation Yaw sweep calculation Central difference expansion around current state Cancel We ll start off by doing a simple solution to obtain the aerodynamic coefficients for the geometry and flight state we have selected Solution started please wait P This row shows that the solver has started cosinat This row signals that calculation is completed and where the results are saved This transfers us back to the main menu and from the post processor menu we can now review the results as plots Figure 25 continued Sample output 41 Tornado plotting functions Clear plots Geometry plot So

USER's GUIDE - Tornado Vortex lattice method

Contents

Download Pdf Manuals

Related Search

Related Contents