A User`s Manual for
Contents
1. enough background information to give the user a good start with using and interpreting the McDaniel Analysis Program for Thermal Protection Systems If an understanding of the methodology of the code itself is desired then the proceeding section was written for that purpose PART II ENCODING METHODOLOGY OF M A P T The author is hopeful that the internal comments within the MATLAB scripts of MAPT will be of some use to the reader in trying to understand the methodology of the files For MAPT three major MATLAB scripts were composed Materials _GUI m Thickness_GUI m and Comprehensive_GUI m Within each of these as is discussed in the TPS section of the Team Daedalus report is the execution of soddit_between m This is the gateway file which executes SODDIT itself but it also serves as the means to create the structural array Data_Collect used to store and collect the SODDIT data An investigation of the MAPT files would should show that soddit_between m is called on occasion and is done so strictly to run SODDIT and to store data within Data_Collect As can be seen in soddit_between m mysoddit m which is the file responsible for compiling the SODDIT input files and reading the SODDIT output files can be executed for a certain amount of material thicknesses heating points or material combinations Materials_GUI m uses soddit_between m to execute mysoddit m for a certain number of material combinations over a single heating point Thickness_G2. plots within the GUI can be disconnected for further ease and this can be accomplished by selecting Disengage Plot X Y By disengaging the plots they can be saved for later use After the optimal materials have been chosen the Thickness Study of MAPT may be undertaken This is accomplished by exiting out of the Materials Study GUI and re typing MAPT into the Exceed provided MATLAB window The option menu will come up once again and the Thickness Study may be selected Accordingly the Thickness Study window will appear with room for the outputs on the right and the inputs on the left By pressing EXECUTE ABLATOR ANALYSIS an example iteration will be run through and the first two figures will produce data as well as the text box below the four plots The first figure shows how much ablation will occur at each indicated heating point for the planet X heating file used and for the initial ablator thickness The second figure shows the same except it provides the ablation for the planet Y heating file used In both cases the ablator selected is indicated in the text box marked Ablator Material File Name MAPT displays these ablation values at the bottom of the screen adds them together and then adds a safety margin as was indicated The initial thickness entered was not important but was required to measure the amount of ablation that would occur It is also important to note that MAPT produced the preceding for the range of heat
3. produced Greg s code changed this He designed a code that could run SODDIT many times over and could collect the data automatically as well It was an incredible advancement of technology for the TPS analysis portion of Spacecraft Design The Heckler Code was not without its own faults however It was lacking in the efficiency of user inputted data and in its method of storing and displaying data Picking up where Greg left off from the Fall of 2003 I began to learn the methodology of TPS analysis as well as the technology of the Heckler code Building off of his technology I was able to create a program that gives the TPS technician full control It is hoped that the time saved by using MAPT will result in more effective designs ideas and research in the future Although MAPT is partly automated it is in no way trivial An in depth understanding of how SODDIT runs and works is definitely a requirement before an understanding of MAPT will foster It is highly recommended to study all TPS literature predating MAPT Everything I now know about TPS design I have learned from the reports and codes of my predecessor G Heckler the SODDIT User s Manual and even my professor This level of understanding is not beyond anyone but will take careful research To begin I suggest to the reader to study as best as possible the SODDIT User s Manual to get a foundation of what everything has been based off Next I suggest to read the TPS section of t
4. professor With MAPT set up and initialized the first thing to do is to set up the initial parameters that will remain the same throughout the entire analysis The easiest way to edit the MATLAB files is to run the normal Windows version of MATLAB even while running UNIX to edit the files contained in your overall directory If you open the MAPT m file with the MATLAB editor you will notice that attention is given to lines 24 through 40 These are the parameters that may be unique to your particular mission but will be constant throughout the whole MAPT analysis The material nodes variable stands for the number of nodes per material a users wishes to have located throughout the depth of the TPS at any location Each node begins at a different height within the TPS thickness with the first node at the surface of the material and the last node on the bottom surface of the material These should not be confused with vehicle heating points however Figure A below should show the relationship between the nodes and the vehicle heating points Windward Surface Depth TPS Cross Section Heating point 1 2 3 4 Figure A A TPS cross section showing the relationship of nodes and heating points Since SODDIT is one dimensional it can only analyze one heating point at a time It does however calculate the thicknesses and the temperatures at each node This data can prove to be helpful if analyzed correctly The inner wall boundary condition te
5. the optimized ablator and the insulator thicknesses they all are to be inputted one after the other in the respective text boxes The provided example should show the correct format The next text box is to include the length of the straight line in meters between the first heating point and the last heating point This number will be used within MAPT to calculate an approximate final TPS mass Also used to calculate the mass is the required surface area of the vehicle that will be covered by TPS Required still is the percentage of the width of the vehicle the user wishes the heating point range to cover Lastly the user would input the densities of the TPS materials By pressing EXECUTE ANALYSIS MAPT takes over and produces two plots and a range of interesting data In the first figure is the ablation behavior with respect to time as the vehicle travels through planet X and then through Planet Y The dark line in the center of the ablator indicates where the ablation left off as it exits planet X s atmosphere and picks up in planet Y s atmosphere The amount of ablative material left after the second planet can be seen resting on the insulator The orange line at the bottom indicates the ceiling of the insulator The second figure shows the inner temperature of the vehicle with respect to time as the vehicle travels through planet X and then planet Y In the second figure the inner temperatures should never reach above the boundary co
6. A User s Manual for M A P T The McDaniel Analysis Program for Thermal Protection Systems Kyle H McDaniel December 2005 AAE 450 Purdue University A NOTE TO THE READER I would like to welcome you to the most recent advancement in TPS analysis for A amp AE 450 s Spacecraft Design The McDaniel Analysis Program for Thermal Protection Systems or M A P T Extensive time has been spent this semester compiling all of the necessary files which compose MAPT a very effective computer program used to perform an in depth analysis of different TPS possibilities Despite all the time that has been put into creating the MAPT Program Package I cannot personally claim ownership of every file used within MAPT In the Fall of 2003 Gregory Heckler composed the Heckler Code a code which had the unique ability to automatically create the necessary input files required to run SODDIT SODDIT or the Sandia One Dimensional Direct and Inverse Thermal Code was the foundation of his design Built by Sandia Laboratory engineers SODDIT has the ability to solve the inverse heat conduction and time integrated heat flux problems In other words it can calculate the temperature and ablation histories for a composite of materials SODDIT is a great instrument to use in TPS analysis however it certainly lacks in efficiency A user would have to automatically create the extensive input file run SODDIT once then manually interpret the output file that SODDIT
7. Nodal Thickness History at Heating Point 3 Thickness m 470 480 490 500 510 520 530 Time s Figure E Further zooming in on Figure C to find an appropriate maximum analysis time Nodal Thickness History at Heating Point 3 Thickness m 475 480 69465 6490 cea 6500 Gra 510s 518 Time s Figure F Further zooming in on Figure C to find an appropriate maximum analysis time Nodal Thickness History at Heating Point 3 Thickness m 0 005 0 01 0 015 476 4 amp 8 480 482 484 486 488 490 Time s Figure G Further zooming in on Figure C to find an appropriate maximum analysis time x10 Nodal Thickness History at Heating Point 3 Thickness m 479 479 5 480 480 5 481 481 5 Time s Figure H Narrowing in on the location of an appropriate maximum analysis time In Figure H after zooming in on the disastrous apex an arrow can be seen that points to the area that the user should aim for The arrow indicates the time right before the SODDIT data blew up This is the location of an appropriate maximum analysis time Further zooming in on this point results in Figure I below Nodal Thickness History at Heating Point 3 Thickness m 4796 479 8 480 480 2 480 4 480 6 Time s Figure I An appropriate maximum analysis time has been found as the arrow indicates The arrow in Fig
8. UI m in the Ablator Analysis uses soddit_between m to execute mysoddit m over a range of heating points for a constant material thickness and for a single material combination Further Thickness_GUI m within the Insulator Analysis uses soddit_between m to execute mysoddit m for a variable value of material thicknesses but does so for a single material combination and for a single heating point Lastly Comprehensive_GUI m_ uses soddit_between m to execute mysoddit m for a range of heating points but only for a single material combination and for a constant material thickness even though soddit_between m is executed with a different material thicknesses each time For all of these changing parameters the structural array Data_Collect was created to store all of the various types of data Although it has three dimensional capability only the two facing planes are needed within MAPT A diagram of the structural array Data_Collect can be seen below as Figure J Material Combos Thickness Variants Figure J Artists rendition of structural array Data_Collect Within Data_Collect are multiple fields each field stored with the temperature histories of every node along with their thickness histories boundary temperatures spans of time maximum temperatures maximum times initial thickness values and even the heating index or heating point These variables are mirrored by their actual names within the structural array as
9. can be seen below T_all_nodes T_boundaries Thickness_hist Time T_max Time_max sweep_value heating_point mat_names mat_orthick Each field has all of the preceding data stored within it and is used by the other files previously mentioned to obtain the data and plots reviewed above in Part I This concludes the basic principles behind storing the data outputted by SODDIT and the use of some of the old Heckler files within the MAPT program If further descriptions of the MAPT codes are required it is suggested by the author to refer to the encoded comments made within the files themselves and to perform a line by line study of the MAPT files themselves
10. e history for both material combinations The temperatures level off because as the ablator ablates away the surface temperature remains constant This is characteristic of an ablator The second plot shows a comparison of the temperatures at the middle boundary of the material combinations The third plot shows the temperatures at the inner layer of the TPS This is the most important plot to take notice of as these temperatures are the ones that are exposed to the actual vehicle It should be desired to keep the inner layer temperatures below the set boundary condition temperature Lastly the fourth plot shows the ablation depths of the materials or how much the materials ablated away The principle in selecting a good material is to choose one that is lightest in weight ablates away at the slowest rate and best insulates the inner structure Seen below the plots is a text window that outputs actual data the maximum inner layer temperatures and the maximum ablation depths All of the provided data should suffice for comparing any two materials To change the material being the analyzed you may type in the designated boxes any material name found within the Materials folder in the overall folder If a new material is wished to analyzed the proper material file must be composed This can be accomplished by referring to the SODDIT User s Manual and learning about the specifications required to write a material file All material files must be saved
11. ended for the reader to select the I wish to perform an In Depth Investigation for Material Combination X at heating point Z option under the default values in order to compare good plots from bad plots It is hoped that this will help the user to know when too large of a maximum analysis time is being used Nodal Thickness History at Heating Point 3 Thickness m Internal Node Figure B Upset 3 D nodal thickness history plot as a result of a too large maximum analysis time Nodal Thickness History at Heating Point 3 Thickness m oO 500 1000 1500 Time s Figure C Upset 2 D nodal thickness history plot as a result of a too large maximum analysis time Figures B and C above show the results of indicating a maximum analysis time that was too large When SODDIT analyzes the heating file past this time the data then tells SODDIT that negative heat flux is occurring which it very well may be SODDIT however cannot handle this and the outputted data blows up characterized by the plots above In finding an appropriate maximum analysis time one must manually zoom in on the plot of the 2 D Nodal Thickness History where the upset data starts to occur Figures D through H give a great depiction of this zooming in process Nodal Thickness History at Heating Point 3 Thickness m 400 450 500 550 600 650 700 Time s Figure D Zooming in on Figure C to find an appropriate maximum analysis time
12. even try to account for everything involved in MAPT or in the TPS design process However an attempt has been made to ease the burden of LPL Kyle H McDaniel A amp AE 450 Spacecraft Design College of Engineering Purdue University learning such new and abstract concepts Good Luck PART I USING amp INTERPRETING M A P T In order to get started the first thing that must be done is to download the files onto your computer account Make sure that all of the files in the original MAPT Program Package exactly as they had been organized are now located on your account Like the MAPT Program Package all the files should be in a single Windows folder and within the folder should be the MAPT files along with another folder entitled Materials This folder should contain the necessary material files needed to run SODDIT Next place the folder containing everything lets call it the overall folder into your individual directory For myself I would place the overall folder in kmcdanie on Samba 3 0 5 roger ecn purdue edu N Next open MATLAB normally and use the MATLAB editor to open the file mysoddit m that lies inside of the overall folder Edit lines 36 and 37 to coincide with your own person path kmcdanie should be changed to your user name and mytpsII should be changed to the name of your overall folder Make sure you save the file and then exit the MATLAB editor Then download putty a telnet UNIX applicati
13. front of the recording screen or the object itself will be recorded also It is furthermore important not to manually close the recording figure when you think that the last frame has completed This could negatively affect the movie When the recording process is complete the frames will close themselves Whether it is wished to play a user created movie or the initial movies first provided when the MAPT program package was downloaded the process is simple There is no need to press an EXECUTE ANALYSIS button Simply press the Play Movie button at the top of the Comprehensive Study GUI It should be found just above the plots Before pressing play the user must select which movie to play When the selection is made the user may sit back and enjoy the animation created by MAPT What is being viewed is a composite of many frames each showing the nodal thickness history over an entire heating point span Each frame was recorded at a different moment in time and when MATLAB puts them together an animation of the actual ablation or temperature history across the heating point span can be viewed Several errors may occur throughout the use of MAPT If one does occur re check the entered data to make sure that the ablator is not ablating completely away or that something wasn t entered incorrectly MAPT has run many times and has proven its capability If there is an error something else other than the MAPT code must be wrong If a prob
14. he final report produced by the MAGAT vehicle team of Fall 2003 This will serve as a basic introduction to what you will be entering into Next carefully study the Heckler Code and the files thereof from the Fall of 2003 for the MAGAT vehicle Try to gain an understanding of what his methodology was in running SODDIT Even try to run the Heckler files on your own Next read over the TPS section of the Fall 2005 Team Daedalus final report This will provide a broad look of what the MAPT program can produce for the user Lastly before running MAPT study the files themselves These can be found in the MAPT Program Package Some of them should look familiar as a few of them have either been edited or taken directly from the Heckler Code Such files may have been edited much or edited a little Carefully study how SODDIT is being executed and why its being executed Study the dynamics of the MATLAB script that occur before and after the SODDIT execution Read the encoded comments and learn about the structural array Data_Collect and how it is used to store and retrieve data It may be helpful to study the Initialization m file a file that lies outside of the MAPT Program package but still may give a glimpse of the stepping stone used to compose MAPT After a proper study of the building process of MAPT itself a knowledge should have been achieved capable of supporting one through the running of the MAPT program This document cannot
15. ing points that was indicated The indicated range of heating points must be in straight line along the surface of the vehicle If two lines exist then MAPT must used once for each line The summed ablation depths with the safety margin are the optimal thicknesses at the indicated heating points for the ablator Recording these values manually is a must as the user will reference them at other times The Insulator Analysis part of the Thickness Study is the next task The selected insulator name is entered in the respective text box as is also the first heating point to be analyzed In the text box for the Ablator Thickness at Heating Point m enter in the optimized ablator thickness at that heating point previously found This number comes straight from the collected data from the Ablator Analysis part Next the initial insulator thickness is entered along with minimum and maximum percentages of the initial insulator thickness to be added or subtracted from the initial value Pressing EXECUTE INSULATOR ANALYSIS will display plots in the remaining two figures In the first figure the projected inner layer temperature history is displayed many times each for a different insulator thickness The principle is to select the minimum amount of insulator required to keep the maximum inner temperature below the inner wall boundary condition temperature This may take several iterations varying the initial insulator thickness or the thicknes
16. lem cannot be found try closing out the window Exceed and the UNIX platform and start it all up once again If the following error results Creating soddit_script exe Error using gt fprintf Invalid file identifier 1 Error in gt create_script at 40 fprintf fp export PATH PATH soddit_path n Error in gt mysoddit at 69 success actual_file_name create_script file_name soddit_path soddit_exe current_directory Error in gt soddit_between at 25 T_max Icv Time_max Icv mysoddit scale cv number_of_materials materials mcv opt_struct block4 header t_init Error in gt Materials_GUI gt pushbutton1_Callback at 180 T_max Time_max soddit_between sweep number_of_materials materials opt_struct block4 header t_init Error in gt gui_mainfcen at 75 feval varargin Error in gt Materials_GUI at 56 gui_mainfcn gui_State varargin 222 Error while evaluating uicontrol Callback Then try closing everything out and restarting If an error shows up saying that the disk quota has been exceeded then your tomb file has been filled and needs to be emptied This can be accomplished by exiting out of Exceed Then on the UNIX platform type unrm This should give you a unrm gt gt prompt At this point type in purge space and hit enter The tomb file will then empty and you may press exit to return to your normal prompt Hopefully this document will provide
17. mperature is another variable to be set initially This is the temperature that the inner structural shell of the vehicle will be exposed to Although this number is not actually used in the calculations it still is used in plots and in data for analysis The number of outputs stands for the number of calculations to be made by SODDIT over a period of time Fifty is an appropriate amount The Titles are simply notes that appear in the SODDIT output file types out and plt The block 4 data was included to give the user an opportunity to analyze not a flat plate but a sphere instead For more information on this consult the SODDIT User s Manual The current default settings are set for a flat plate assumption With these initial figures set and the MAPT m file saved MAPT is now equipped to run adequately Typing MAPT in the Exceed generated MATLAB window will run the program At first you will be given the option to choose between three studies the Materials Study the Thickness Study or the Comprehensive Study The Materials Study would be the first option to select After clicking on the button you will notice that the required inputs are all located on the left side of the screen as is the case for all of the MAPT studies By selecting the first material of each combination to be an ablator and then hitting the EXECUTE ANALYSIS button you will see several comparison plots The first is a plot of the surface temperatur
18. ndition as the insulator has been optimized and in the first figure the ablation should never sink below the safety margin Aside from the data outputted which will be left for the reader to explore the next outputs of major interest are the TPS masses By using a polynomial fitting technique with the inputted thicknesses and computational integration a final TPS mass for the ablator and the insulator can be solved for The exact method may be explored within the Comprehensive_GUI m file It is important to note that unless the percent of surface covered by the heating point span was 100 the displayed masses are not all inclusive If two lines of heating points exist for example one line possibly down the center of the vehicle may be assumed to serve as 33 of the vehicle while the other line possibly between the center and the side may serve as 33 on each side but 67 would be used to account for that line on each side of the vehicle If the user selects the Create Plot of TPS Material Shapes along Heating Point Span button a plot will result of the actual shapes of the TPS materials one laying on top of the other Lastly the Comprehensive Study includes the option to create movies of plots 1 and 2 with respect to time If one of these options is selected be prepared to wait for around one hundred frames to display and save Each frame takes about 2 seconds to display and save Also be careful in this process not place anything in
19. on from the internet It is an application so there shouldn t exist any problems downloading it This can be done for free and once accomplished place on your desktop for ease of use This tool is required for MAPT because the Heckler Code as well as MAPT was designed to run off of a UNIX platform not a normal windows platform Although MATLAB can be run easily on UNIX the graphics cannot be displayed without the use of Exceed 10 0 Execute then from Windows the program Exceed 10 0 and let it initialize After it minimizes on the computer screen execute putty Within putty click on Tunnels which will be on the left of the window and should be a subsection of SSH a subsection of Connection After clicking on Tunnels select Enable X11 forwarding Then click on Session again at the left of the window and for Host Name type in roger ecn purdue edu or any other server name where your account can be accessed Log in using your user name and password and navigate to the overall folder Once inside type MATLAB in the UNIX prompt You may or may not have to type in kill It may be necessary however MATLAB should then start in UNIX along with visuals via Exceed 10 0 It will be in the main Exceed provided MATLAB window that you will initialize MAPT m Typing MAPT in this window should execute the MAPT Program If you encounter any problems try to get help from a computer savvy student or your
20. s variant values as they be called to obtain an appropriate value Note that the fourth figure also displays inner layer temperature histories but it does so for planet Y Whichever planet shows the largest increases in temperature will be the only planet of interest for the insulator analysis This is because if an insulator is designed to meet the conditions of the hottest planet then it certainly is designed to meet the conditions of the coolest planet Also notice on the left is an option to print values for planets X or Y Whichever planet is the one of interest should be selected This will provide actual maximum temperature data for a particular insulator thickness After the optimal insulator thickness has been found it may then be corrected for a margin of safety and then manually be recorded by the user All of these values will be needed for the Comprehensive Study The above process is then repeated for every heating point that is sought to be analyzed The resulting thicknesses of the ablator and the insulator are therefore optimized at each heating point for the mission and are each unique to their particular heating points With these values the last study may be performed the Comprehensive Study After selecting Comprehensive Study from the MAPT options menu the window will appear again with the inputs on the left and the outputs to be displayed on the right Much of the data to be entered near the top will be the same as before For
21. ur after the SODDIT data turns poor More research may be undertaken in the future surrounding this fact Since no meaningful analysis can be performed by MAPT without a maximum analysis time this temporal point must be found This can be accomplished easily within the Materials Study Simply enter the name of the heating file in question in the proper place Then set the maximum time to be the full time of the heating file itself This number can be found by opening the heating file with the MATLAB editor and scrolling to the very bottom On the far left should be the largest time value Once this number has been entered select the I wish to perform an In Depth Investigation for Material Combination X at heating point Z button Fill in 1 or 2 for X and set Z to be the number of one of your columns in the heating file as these represent the data for a specific vehicle heating point Normally this selected option can give the MAPT user a very complete understanding of everything that is occurring at the indicated heating point The option produces plots displaying nodal temperature and thickness histories at that heating point When used to determine the maximum analysis time however the resulting plots will look much different than they would normally appear and they are all characteristic of the poor data caused by a maximum analysis time that was too large Examples of such plots can be seen below as Figures B through C It is further recomm
22. ure I shows the time right before the SODDIT data turns poor This is an appropriate maximum analysis time However it still must be noted that even this time may be slightly too large for analysis If resulting official analysis plots later on show small discrepancies toward the end of the analysis time most likely the maximum analysis time should be reduced still Usually however these reductions shouldn t have to be more than a second Once the maximum analysis time has been found it may be used for the particular heating file in question Thankfully this process of locating the maximum analysis time only needs to be done once for each heating file used If a new heating file will be used in the future whether within the Materials Study or any of the other two Studies of MAPT a new maximum analysis time will need to be found for that heating file Elaborating on the In Depth Investigation it can prove more useful than just solving for the blow out time It provides much more meaningful plots which can only be displayed for one heating point one thickness and one material combination at a time This investigation actually creates plots from a single field in the structural array Data_Collect and they can prove quit useful in determining TPS behavior at a specific point or with specific conditions This process will become more clear as you familiarize yourself with Data_Collect Also an option on the GUI are the plot disengagements The
23. within the Materials folder talked about previously To change a material thickness simply enter in a different value in the respective text box However in the Materials Study it is important to keep as many variables the same as possible between different combinations This study is to determine an optimal material only not optimum thicknesses If a material is an ablator make sure that you select the ablator button lying below it If you do not an error might result such as the one seen below insufficient data on density record In the middle is a space to enter the name of the heating file to be used The purpose of the heating file is discussed at length within the Team Daedalus Fall 2005 final report If a different heating file is used it is important to note that the actual file must be located within the overall folder but NOT in the Materials folder That folder is for material files only The next input the maximum analysis time is a critical value that needs attention Because SODDIT cannot analyze any data after the actual vehicle begins radiating heat away from itself the SODDIT data blows up or becomes non meaningful Therefore since an updated version of SODDIT has yet to be made available every heating file can only be analyzed up to a certain time when the heat flux becomes negative At this point the ablation will stop but current research shows that a mild increase in inner layer temperature will occ
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