BladePro-CF: An ANSYS-based Impeller Analysis System
Contents
1. gt 40 t x se ae x ae i ag ait x E bets 4 E x Mk F 0 Steady Stress 3765 3765 nodes selected Figure 15 Goodman diagram Fatigue Analysis In BladePro CF as an alternative to the Goodman diagram the strain life approach is available to predict fatigue life This approach will be typically used to predict LCF damage at locations with high static stresses such as notches or fillets The input to the local strain fatigue module consists of elastic stress strain history over a certain time block The fatigue analysis module generates a detailed report that describes the following information maximum minimum true stress strain throughout the entire loading history damage caused by LCF and HCF respectively total damage throughout service time and number of blocks prior to the failure An example of this report is shown in Figure 16 ma Fatigue Analysis Report o es File Help TEES High cycle fatigue elastic stress of sampled High Cycle Fatigue data points 36000 of High Cycle Fatigue frequency components 1 Freq HZ4 Ampl Phase Deg Detuning Freq Ret damping Actual damping 1 41600E 003 5 Q00000E 003 O 00000E 000 O 00000E 000 2 Q00000E 005 2 00000E 003 wea Residual stress at the end of LCF stress ttt Residual stress in HCF 7 69958E 004 Maximum stress throughout the entire LOF HCF history 9 72540e 004 Minimum stress throughout the entire LOF HCF history 6 842. Nodal Diameter 0 Frequency 2816 15 Hz Mode 6 Figure 12 Mode shape animation and generation of interference diagram Harmonic Response Analysis It is a straightforward process to focus on several critical modes that are identified by using the Interference and the Campbell diagrams Figure 13 left shows a one nodal diameter mode in the second family mode The modal animation indicates that the motion is dominated by the airfoil flap wise vibration at the inlet regions The vibratory stress is shown in Figure 13 right 24 Mode Shape Animation E Temp onespl_Eige i A i File Options Help Al R M M Animate em blode T Frequency 2926 56 Hz fal 041513 2 445 4 B48 T 25L 9 654 12 057 14 46 16 363 19 267 L 67 i x e Bld L Fey 2626 556693 Hor 1 Stim 2 E 02 Rel Fh D Damp 2 E 03 Figure 13 1 nodal diameter tangential mode shape left and vibratory stress distribution in the 1 ND mode Campbell Diagram Campbell diagram shows the shaft speeds at which a resonant condition 1s predicted Campbell diagram considers the change in blade natural frequencies with speed stress stiffening and spin softening effects as well as the harmonic content of the mode A good constant speed impeller design will provide adequate speed margins on either sides of the nominal operating speed Adequate speed margin will assure in low vibratory stresses and will provide protection against variation in impeller fre
3. database Some additional features BladePro CF also supports modeling the following features multiple splitter blades and definition of airfoil surface using multiple streamlines Multiple splitter blades Splitter blades in an impeller can help control the flow induced vibration Under most circumstances one splitter is sufficient The impellers with more than one splitter are rare but they do appear in some industries Currently BladePro CF can model up to 3 splitter blades Figure 8 shows one impeller with 2 splitter blades Multiple streamlines This is a newly added feature of BladePro CF Previously the airfoil surfaces are constructed based on a series of straight line stations from shroud to hub With this new capability however one station line is generally represented by a curved line that is defined by a series of points each from one streamline to which it belongs Users geometry input provides a straightforward construction of a mean airfoil surface An advanced surface construction algorithm is developed to construct both pressure and suction surface based on this mean surface and the thickness distributions as well as other model geometry data The splitter blade 2 in Figure 8 for instance has a curved surface that is defined using multiple streamlines The definition of airfoil using multiple streamlines allows the modeling of a generic curved airfoil surface WF Figure 8 An impeller with 2 splitte
4. has the capability to import certain types of files exported by other complementary programs such as TurboGrid IMPRO BladePro CF relies on filename extensions to associate files with certain programs Once the file is imported it should be saved into a BladePro CF file with an extension name BPR Model Input This menu allows the user to define component geometries including airfoil cutback shroud and hub etc Aerodynamic force can be defined as well Generate Model This menu generates the finite element model and associated user specified boundary conditions BladePro CF can generate both single sector and full wheel FE models Analysis This menu launches a variety of analysis types including steady stress analysis modal analysis at any impeller speed harmonic response analysis and fatigue life estimation Post process BladePro CF provides users with powerful and intuitive post processing capabilities of FE results The post processing functions available under a specific analysis scenario depend on the type of analysis users conducted Help Html based on line user manual is provided Additionally hitting F1 provides a context sensitive help for all the dialogues ANsYs Mechanical U Utility Menu i 5 x File Select List Plot PlotCtris WorkPlane Parameters Macro Menuctrls Help O S a alel Z ANSYS Toolbar A I BladeProcr O x EE eee ee ey eo eee File Mod
5. radial and axial coordinate as well as the fillet radius at that point Boundary conditions associated with each keypoint can be specified as well BladePro CF provides users with ample mesh controls The hub mesh control has two options default and user defined For the default option the total numbers of elements in both tangential and radial directions can be specified For the user defined option the users can select the number of elements on each line of the hub profile Then users need to go to Model Input gt Hub Data gt Hub User Defined Mesh to run the qmesh program which meshes the hub portion using a built in free mesh manner A qmesh window as well as the resultant free mesh of the hub face is shown in Figure 3 The qmesh module allows the user to quickly mesh the hub to generate a satisfactory mesh in the radial axial plane before proceeding with a full 3 D mesh for the impeller xf Number of points 4 gt Convex arc indicated by Positive radius Plot Hub Axial Radius Ee Transformations 0 0 z 40 0 0 0 Yes KP3 Mesh Control soo oo No KF soo oo No KP3 Update Plot KP2 z Cancel Help Figure 2 Hub input window EE QMESH isplshd qsh le x File Options Window Help EE ox amp D M PS_ Gen Mesh Mesh opt af H 5 ora mra H Error Check Options S c a PHR TESSAN LAS Coordinates X 84 000 Y
6. 54 118 Mesh Options 1 1 1 1 5 1 6 110 elements Score 23 8637 Illegal elements 0 Min angle 20 Max angle 180 Figure 3 Qmesh window Airfoil Figure 4 shows the airfoil input window BladePro CF defines a 3D airfoil geometry using multiple streamlines with each streamline defined by a series of points For a given input section each streamline is a mean line between the corresponding suction side and pressure side curves Each point on this mean line has radial and axial coordinate an angle and associated normal thickness R Z Theta Thickness Additionally a fillet radius can be specified for pressure and suction sides For each streamline up to 100 points can be specified The streamlines can be viewed individually or multiple streamlines can be stacked and viewed together The airfoil input window also allows the user to specify mesh densities and the number of airfoil master degrees of freedom used in the modal analysis BladePro CF allows the user to define the so called flow cut Flow cut is essentially a cutting line above which the portion of airfoil defined by the input streamlines will be removed This feature allows a convenient way to quickly generate models from the same basic geometry but for different flow rates BladeProCF Blade Data xi Type of input Flow Cut Streamline 1 Hub 2 3 4 5 Shroud Insert Before Plot Streamlines of pts G Span oo Fillets Plot Str
7. 915e 004 ee Fatigue assessment Damage caused by LCF stress within the analysis time 3 79212e 002 Damage caused by HCF stress within the analysis time 9 6357 se 004 Total damage throughout the analysis time 10 000000 years 3 88684 7e 002 Total number of blocks LCF HCF to failure 25 Figure 16 Report of fatigue analysis Summary This paper summarizes the architecture and analysis capabilities of BladePro CF an ANSYS based impeller wheel analysis program The development of BladePro CF fully takes advantage of the strengths of ANSYS such as robust and fast solvers efficient memory usage and powerful post processing capabilities ANSYS APDL language has been used extensively throughout this software Tcl Tk interpreter within ANSYS has been used extensively to develop the graphical user interface BladePro CF can be made available to run on any ANSYS supported platform In summary BladePro CF clearly shows how to effectively leverage vertical integration capabilities within ANSYS to build custom applications BladePro CF can be effectively used as An analysis tool to ensure mechanical integrity of impeller wheels A diagnostic tool to conduct Root Cause Analysis RCA to explain why a blade or a wheel failed A redesign tool to verify proposed changes to a design Acknowledgements The authors would like to acknowledge the contributions by Ben Atkinson Ryuichi Machida and other team members in the continued develo
8. BladePro CF An ANSYS based Impeller Analysis System Dr Wangming Lu Mark L Redding Avinash V Sarlashkar Impact Technologies LLC Rochester NY 14623 U S A Abstract This paper presents the architecture and capabilities of BladePro CF an ANSYS based analysis system developed to assist engineers in the structural assessment of radial and mixed flow impellers The automated tasks include finite element model generation boundary condition application file handling and job submission and queuing of analysis jobs and impeller specific post processing tools The F E model generation features both open and closed shrouded impellers multiple splitter blades hub geometries with arbitrary back plane profiles variable fillet radii at both hub and shroud surfaces user controllable mesh densities and definition of blade surfaces using multiple streamlines Also both single sector and full wheel models can be generated The analysis capabilities include steady and vibratory stress calculation frequency and mode shape calculation and low and high cycle fatigue life predictions BladePro CF includes impeller specific post processing capabilities such as intuitive stress and displacement viewing animated mode shape plotting auto generated interference and Campbell diagrams This paper uses a real world application to demonstrate these capabilities BladePro CF can be primarily used as an analytical tool for facilitating the design of struct
9. ODAL JLI E STEP SI SUE 1 TIRE 1 TOE 1 ET EDF jirg EFACET l EFRCET L AVEES ea amp AvVFES aHat DEE i7555 DHA 1733H zN J0 MH 1 10 Tt p 5T F dh ora Li ial PES Ls fr p Es d a0 570 Dasa iapallaz analyaiz Von Ninar atrcaax Nom Figure 11 von Mises stress distribution at 18000 RPM MPa For a single sector left and for the whole impeller model right Popsrirsphiga At speed Modal Analysis Based on at speed modal analysis results an Interference Diagram as shown in Figure 12 is automatically created by BladePro CF Figure 12 also shows the mode shape and the harmonic content for the selected mode Mode shape animation helps user visualize the deformation pattern around the impeller The display of harmonic contents of a mode can help users to find whether it will be excited by a given external excitation pattern for example inlet guide vane excitation The ultimate goal is to avoid impeller resonance that can lead to high vibratory stress mation ENT EEN E rerterence niaren T Fie Options Help Options 0 20 R M M P Animate Amp TE Speed rat oO 8000 ey o 8 8 6000 Oo ia D 3 S a 4000 i x iu oO g 6 oO Freq 2816 15 90 Node 202 80 Max Tang 158 347206 Max Axial 151 540998 70 20004 9 bi E Tangential 60 o Axial 50 40 30 20 10 0 0 0 1 2 3 4 5 6 7 8 DR or Harmonic 0 J 2 3 4 Nodal Diameter 4 gt
10. Type L217 300 M Fe 0O 43C 1 9Ni 1 681i 0 8Cr 0 4Mo V 70 0 Hub 1217 Type L217 300 M Fe 0O 43C 1 9Ni 1 68i1 0 8Cr 0 4Mo V 70 0 Hub Fillet 1217 Type L217 300 M Fe 0O 43C 1 9Ni 1 681i 0 8Cr 0 4MotV 70 0 Calculate Properties Cancel Help Figure 6 Component material input window Material database BladePro CF contains a comprehensive material database with mechanical thermal fatigue and Goodman material property data sets see Figure 7 Users can add their own material properties to the material database The material property can be plotted as a function of temperature A BladeProCF Material Database Ioj xj Mechanical amp Thermal Fatigue Goodman Material ID Add Delete 1217 Type 1217 300 M Fe 0 43C 1 8Ni 1 685i1 0 8Cr 0 4MotV Copy Edit Material type 1217 Units English Description Type 1217 300 M Fe 0 43C 1 8Ni 1 65 0 8Cr 0 4Mo Reference temperature 0 of temperature points 7 Plot Material Properties Temp YoungMod PoissonRat Density CffThrmEx Spec Heat Thrm Cond i Ib in 3 in in F BTU Ib F BTU hr ft F Bos 0 29 6 3 0 107 21 7 2 9e 007 0 0 283 6 95 0 22 2 2 8e 007 0 0 283 7 4 0 22 5 2 7e 007 0 0 283 7 65 0 21 5 2 6e 007 0 0 283 7 8 0 20 1 2 5e 007 0 0 283 7 65 0 18 5 1200 2 1e 007 0 29 0 283 7 4 0 107 17 fi Figure 7 Material
11. adeProCF Shroud Data xt Shroud type lintegral gt Plot Shroud Transformations Update Plot Number of points 6 Radial Axial Radius 128 35 0 zi Convex are indicated by Positive Radius Figure 5 Shroud cover input Splitter blade Splitter blades can be defined in two different ways One way is to define geometry of a splitter blade in the same fashion as the main blade Alternately for the cases where the splitter blade has the same geometry as the main blade user can specify a pitch fraction to locate the splitter relative to the main blade and then also define the axial location for the start of the splitter At the present time up to 3 splitter blades per sector can be modeled Cutback A cutback defines the number of blade stations to ignore when determining where the actual geometry begins and ends It is applicable to shroud blade and hub input After all the necessary geometry is specified user can verify the input data through graphical display Component model material For finite element calculation appropriate material should be assigned A component material specification window is shown in Figure 6 The temperatures operating temperature at which the material properties should be evaluated during the analysis can be specified as well aE Component Material ID Temp Shroud 1217 Type L217 300 M Fe 0O 43C 1 9Ni 1 681i 0 8Cr 0 4Mo V 70 0 Blade 1217
12. citation force pattern BladePro CF facilitates this check by classifying the calculated modes on the basis of nodal diameters or the harmonic content Strong harmonic stimulus and low damping 5 Fatigue Analysis BladePro CF provides two approaches to fatigue analysis the first approach is a stress based approach while the second approach is a strain based approach The first approach is the traditional Goodman diagram BladePro CF plots each of the nodes on the Goodman diagram In BladePro CF the Goodman diagram can be simultaneously plotted using vibratory stress responses from up to 5 modes Vibratory stress response for each of the modes is plotted independently This facilitates easy identification of critical modes Further the user can plot the Goodman diagram for a set of nodes from part of the FE model for example the shroud This is very convenient in identifying critical stresses locations for each mode of vibration The second approach uses the local strain methodology for fatigue life estimation The local strain approach is able to handle material damage due to both the low cycle fatigue LCF and the high cycle fatigue HCF Typcially high bore stresses would require LCF analysis to address material damage due to start stop cycles Likewise vibratory stresses in the airfoil due to a potentially resonant mode will require HCF analysis The local strain module provides the option to use either Morrow s method or Mans
13. eamline Transformations Insert After Transformations Radial Theta Deg Axial Tn Fp Fs Conn 1 1974e 0140 00093847 Mesh bes abil 0 734606 20 1 0 Yes 279548 213687 1 26706 20 10 Yes i 5 42693 4 2728 1 73503 20 10 Ys o m 10 2254 8 54454 231223 20 10 Yes 30 0721 124083 10 6802 252365 20 30 1245 14 457 128155 269781 20 30 1978 16 379 14 9501 295131 20 30 2958 181818 17 0838 298059 20 30 4222 19873 19216 310475 20 20 Yes 20 Yes 0 o 0 oe a RT4 Tn input Delete 30 0 30 0048 30 0158 30 037 Re Number i 30 7775 31 0153 31 2997 31 6359 32 0294 32 486 33 0118 24 3521 25 5955 3 38257 25 6718 27 7123 3 45541 26 9172 29 8216 3 52824 28 0952 31 9209 3 58955 29 2127 34 0074 3 64392 30 2763 36 0775 3 69829 31 292 38 1269 3 74654 32 2656 40 1506 3 78657 2 1 0 Yes 34 2958 7 i Cancel Help Figure 4 Airfoil input Shroud Shroud geometry can be defined as shown in Figure 5 Only the outer surface of the shroud profile is defined The inner surface is defined by the blade tip geometry Again each point location is defined in the radial plane by its radial and axial coordinates Any two consecutive points T and I 1 can be joined either by a straight line or by an arc Bl
14. elInput Generate Model Analysis Postprocess Help 3 ANSYS Main Menu AN S Preferences gt Preprocessor OCT 31 2003 Solut E Ge Postp E TimeHist Postpro Topological Opt E Design Opt Prob Design Radiation Opt Run Time Stats B Session Editor Finish Pick a menu item or enter an ANSYS Command BEGIN mat 1 type 1 real 1 csys 0 Figure 1 BladePro CF main menu Since BladePro CF is launched from within an ANSYS session user always has the option to use the ANSYS command line or the pull down menus to perform any standard ANSYS operations In what follows the functions of BladePro CF are described on a menu by menu basis File Menu In addition to the standard functionality such as File Open File Save etc BladePro CF provides importing geometry from other complementary programs Currently the following file types can be imported IMPRO COMIG and TurboGrid Model Input Menu Model Input Menu allows the user to define geometry information on a component by component basis Hub Figure 2 shows a hub data input window In BladePro CF the hub profile geometry is defined in the Radial Axial plane by a series of points Up to 200 points can be used to define the hub profile These points are only used to define the exterior of the hub profile along the bore and back plane the hub profile in the flow region is defined by the blade geometry Each point is defined by its
15. gn variations instead of variations in mesh size and topology Currently BladePro CF s analysis tools include steady stress analysis with loading due to centrifugal force and or aerodynamic force modal analysis at any impeller speed harmonic response analysis and fatigue life estimation To help users evaluate the structural integrity of a proposed design from various aspects BladePro CF provides the turbo machinery specific post processing tools to generate the Interference Diagram the Campbell Diagram and the Goodman Diagram The Goodman diagram is provided for each node in the model This paper is organized as follows First the general architecture of BladePro CF and the main features within each menu are described Then the analysis capabilities of BladePro CF are discussed Next the comparison between BladePro CF over IMPRO mainly in terms of solution time required is presented This is followed by representative results from analysis of a real life impeller General Architecture BladePro CF has four modules Model input Model generation Analysis and Post processing Model generation module uses a combination of FORTRAN C amp ANSYS APDL The user interfaces are developed using the native ANSYS support for Tcl Tk As shown in Figure 1 BladePro CF is launched from within ANSYS by clicking BladePro CF in the ANSYS toolbar As shown in Figure 1 the main menu contains six items as described below l File BladePro CF
16. ill be compared with the results from a standing test 3 At speed Modal Analysis Likewise natural frequencies and mode shapes can be calculated at any shaft speed Compared to the ORPM frequencies and mode shapes the at speed calculation includes the effects of stress stiffening spin softening and temperature at the operating speed Typically modal analysis is performed at multiple speeds and a Campbell diagram generated to identify any potentially resonant modes in the operating speed range for the impeller 4 Harmonic Response Analysis The Campbell diagram facilitates the identification of potential resonances in the operating speed range for the impeller However it does not provide information about the expected level of vibratory stresses and their distribution throughout the impeller BladePro CF the harmonic calculation is based on the principle of modal superposition and therefore a modal analysis is needed prior to the corresponding harmonic response calculation It is mainly used to calculate the vibratory stress when the structure is excited at one potential resonance frequency Both the stimulus ratio and damping can be specified For a real engineering analysis the requirements of higher vibratory stress can be as follows The coincidence of the natural frequency of a rotating impeller and the frequency of an excitation for example that caused by inlet guide vanes Strong modal coupling between the mode shape and the ex
17. nvenient mode classification BladePro CF Performance and Solution Times This section is concerned with the solution performance of BladePro CF The calculation is performed on a 2 GHz PC with 1 5G RAM running on Windows NT 2000 ANSYS version is 7 1 The model generation times are typically less than 15 seconds and therefore only elapsed time for different types of solutions 1s of relevance Over the last 5 10 years ANSYS has made a tremendous progress so far as solver technologies are concerned This progress is quite evident in the significant reduction in solution times for both static and modal analysis Furthermore the use of the Block Lanczos solver has allowed the users to run modal analyses with ever increasing DOFs in the model and therefore has improved the prediction accuracy Our experience shows that Block Lanczos solver is the optimum choice for both static and modal analysis For static analysis on a typical single sector model FE model with 2744 elements and 9078 nodes BladePro CF s solution time is only 8 seconds For the same model the solution time for modal analysis is 116 seconds It should be noted that this time saving depends on the size of FE model of interest as well as the solution related controls It 1s evident that ANSYS advanced solution technologies enable users to obtain the analysis results quickly A Complete Analysis Example This section presents a complete analysis example using BladePro CF The main p
18. on amp Halford s method to account for mean stress effects For any of the analyses above the necessary boundary conditions are generated during the FE model generation The user needs to only provide minimum information to initiate the analysis For example the RPM at which the stress or natural frequencies need to be calculated Additionally BladePro CF allows the user to access solution related ANSYS controls such as the selection of solver the number of processors to use etc Post Processing Menu BladePro CF offers post processing tools that are specific to turbomachinery design analysis The fundamental considerations in the design process of an impeller are the static stresses typically high in the bore the speed frequency margins and vibratory stress response Depending on the application an impeller may operate at constant speed or may operate at any speed over a range of speeds In the case of a constant speed machine calculation of frequency margins is important In the case of a variable speed machine speed margins from potentially resonant modes as well as the corresponding magnitude of resonant stresses is important BladePro CF offers the following post processing information that is specific to design analysis of turbomachinery Automatic generation of Interference Diagram to check for frequency margins at a constant operating speed Automatic generation of Campbell diagram Mode shape animation for co
19. pment of BladePro CF References 1 ANSYS 2000 APDL Programmers Guide ANSYS Inc ANSYS 2000 Guide to ANSYS User Programmable Features ANSYS Inc ANSYS 2000 Guide to Interfacing with ANSYS ANSYS Inc Welch B 1997 Practical Programming in Tcl and Tk Prentice Hall ANSYS 2000 ANSYS Online Documentation ANSYS Inc Ne Saw ies ee Bannantine J A Comer J J and Handrock J L 1990 Fundamentals of Metal Fatigue Analysis Prentice Hall
20. quencies due to inaccuracies in manufacturing and scatter in material properties The gyroscopic damping is not considered in the construction of Campbell diagram Figure 14 shows a Campbell diagram Ta Campbell Diagram E ANSYSPAPER Data onespl cbl i oj xj Fie Options Help EEEE 8000 7000 6000 in m 4000 Frequency Hz Ld oOo oOo 2000 1000 0 e d 18000 RPM 18000 RPM 20000 40000 60000 80000 100000 120000 140000 160000 180000 2000C Speed RPM O Family g A Family 2 Family 3 Family 4 Figure 14 Campbell diagram Goodman Diagram It is used to assess mechanical integrity by considering both steady and vibratory stresses The steady stress is predominantly from the centrifugal loading The vibratory stress corresponds to one or more potential resonances identified on the Interference Campbell diagram Figure 15 shows a Goodman diagram where vibratory stresses for three modes are plotted concurrently BladePro CF allows the definition of the Goodman envelope with multiple straight line segments Are Diagram E DD onespl gdm oj x File Options Help Max Principal Stress von Mises Stress ivon Mises Stress il x mode 1 mode 2 mode 3 Vibratory Stress 44t 4 gt x peed ae le Pi 3 ft lt 4 F 9 oh 5 x x x 4 t x x e ag eg ik y pr ph o t4 wae i ee T y pe rp oe mete g Faek ae T
21. r blades Blade surfaces were defined by multiple streamlines Generate Model Menu Figure 9 displays a typical impeller FE model In this figure only one sector model is generated Some impellers may have shroud and or splitter blades For example the impeller shown in Figure 9 has a shroud and splitter blades In addition BladePro CF supports full wheel model generation A full wheel FE model is shown in Figure 10 Figure 9 A typical impeller finite element model Figure 10 A full wheel FE model with shroud shown left and with shroud not shown right Analysis Menu BladePro CF provides the following analysis capabilities 1 Static Stress Analysis The static stress analysis can be conducted for a single sector or a full wheel FE model Supported loads include centrifugal load aerodynamic forces and thermal loads If a single sector model is used the cyclic constraint boundary condition and cyclic load are applied Non cyclic load cannot be applied ANSYS cyclic analysis is not used Instead in BladePro CF ANSYS macros are developed to implement the static stress calculation based on the cyclic constraint boundary conditions 2 0 RPM Modal Analysis Natural frequencies and mode shapes at 0 RPM i e standing frequencies can be calculated in Blade CF Multiple natural frequencies are calculated for each circumferential wave pattern harmonic index Typically as part of FE model verification the predicted modal results w
22. urally sound wheels a diagnostic tool for doing Root Cause Analysis RCA to explain why a blade or wheel has failed and a redesign tool to confirm the improvement of an existing design Introduction BladePro CF has evolved from the standalone impeller analysis program IMPRO The transition from IMPRO to BladePro CF is driven by a variety of enhanced capabilities offered by the ANSYS program These enhanced capabilities include Continuous development of fast and efficient solvers capable of handling large scale problems on the most current hardware and operating system technologies Built in Tcl Tk interpreter providing native support for graphical user interface development Ability of the native Tcl Tk interpreter to access internal ANSYS data items necessary for model generation boundary condition application and post processing Continuous enhancements to post processing functionality The end user for BladePro CF is anyone involved in design testing and or failure analysis of compressor wheels BladePro CF provides the end users with a menu driven easy to use analysis tool The point and click interfaces are provided for data input model generation analysis and post processing In addition users are given the necessary control over the FE model mesh densities This mesh control is important for users during their design iterations since it will allow users to focus on the result variation exclusively caused by the desi
23. urpose is to demonstrate typical analysis procedure using BladePro CF to perform a structural integrity assessment The analysis covered in this section includes steady stress analysis at speed modal analysis harmonic response analysis and fatigue analysis The impeller has 9 main blades and 9 splitter blades The tip diameter is 22 1mm Nominal operating speed is 18000 RPM The impeller is made of Cast Aluminum C 355 0 with the following mechanical properties Yield strength 30 ksi 0 2 offset Young s modulus 10 29E3 ksi and density of 0 097 Ib in 3 All reported stresses and deformations are based on the linear elastic assumption for the model Steady Stress Analysis Figure 11 left shows the distribution of von Mises stress throughout the impeller The maximum computed stress is 80 5 MPa 11 7 ksi This is an acceptable stress level for Cast Aluminum C 355 0 with yield strength of 30 ksi As mentioned earlier BladePro CF supports the steady stress analysis for the FE model of the whole impeller Figure 11 right shows the distribution of von Mises results that are obtained based on the finite element analysis of a full impeller FE model As expected the von Mises stress results predicted from a full model analysis are identical to those predicted from a single sector model However the analysis time required by a single sector analysis 1s only about 20 of that required for a full model analysis kars 7 1 E AHSS T 1 HIAL SOLITID R
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