MAE We of onferenes 114, 21 (217) DI: 1.151/ mteonf/21711421 Modulr simultion softwre development for liquid propellnt roket engines sed on MALAB Simulink Mhyr Nderi 1, Guozhu Ling 2 nd Hsn Krimi 3 1 Ph.d ndidte, Shool of Aeronutis nd Astronutis, 1191 Beihng University, hin 2 Professor, Shool of Aeronutis nd Astronutis, 1191 Beihng University, hin 3 Assoite Professor, Fulty of Aerospe Engineering, K.. University of ehnology, Irn Astrt. Fousing on Liquid Propellnt Roket Engine (LPRE) mjor omponents, stedy stte modulr simultion softwre hs een estlished in MALAB Simulink. For integrted system nlysis, new lgorithm dependnt on engine inlet mss flow rte nd pressure is onsidered. Using the suggested lgorithm, it is possile to evlute engine omponent opertion, similr to the known initil prmeters during hot fire test of the engine on stnd. As se study, the reusle Spe Shuttle Min Engine (SSME) hs een seleted nd the simultion hs een performed to predit engine s throttled opertion t 19 perent of the nominl thrust vlue. For this purpose the engine tul flow digrm hs een onverted to 34 numeril modules nd the engine hs een modelled y solving totl of 11 stedy stte mthemti equtions. he men error of the simultion results is found to e less thn 5% ompred with the pulished SSME dt. Using the presented ide nd developed modules, it is possile to uild up the numeril model nd simulte other LPREs. 1 trodution order to redue the osts during design nd enhnement phses, using softwre ple of preise modeling nd simulting is fvorle. For this purpose in this reserh simultion tool is developed for stedy stte nlysis of RLPRE whih n e further extended for simulting other ts of LPREs. development of simultion softwre for LPRE nlysis, mny ontriutions hve een done for exmple in 1995,. Goertz suggested modulr method for stti performne nlysis of different LPRE yles using Fortrn (s it ppers). [1]. 2, K. Liu, Y. Zhng developed methodology for modulriztion modeling nd trnsient simultion of LPREs nd reted n ojet oriented progrm using Mirosoft Visul ++ 6. [2]. 29,. R. Koppel et l.; used EosimPro tool kit long with ESPSS lirries to implement nd vlidte stellite propulsion systems modellings [3]. 211, F. D. Mtteo nd M. D. Ros developed stedy stte lirry for ESPSS softwre for stti simultion of liquid propellnt engines [4]. 212, Y. Zheng et l. used the AMEsim softwre to simulte the dynmi ehvior of unified sperft propulsion system [5]. 213, M. Nderi, A.R.Jlli et l. developed GUI softwre for dynmi simultion of open yle LPRE using FRRAN 9 [6]. 215, L. Wei et l. used Modeli to estlish omponenet model lirries for LPRE [7]. As it is visile, y the evolution of omers, the reserhers re tending towrds Guozhu Ling : lgz@u.edu.n he Authors, pulished y EDP Sienes. his is n open ess rtile distriuted under the terms of the retive ommons Attriution Liense 4. (http://retiveommons.org/lienses/y/4./).
MAE We of onferenes 114, 21 (217) DI: 1.151/ mteonf/21711421 developing more generl softwres similr to toolkits. the urrent reserh in order to nlyze different ts of LPRE yle performne, modulr simultion softwre hs een developed for stedy stte nlysis, using MALAB Simulink. Here MALAB is hosen due to its high essiility, ppliility, simple progrmming lnguge, onvinient usge, rih lirry nd tooloxes for different mthemtil solution methods nd finlly ese of opertion for future reserhers to enhne the urrent softwre. Despite some of the previous litertures, the presented lgorithm uses engine inlet mss flowrte nd pressure s the system in, similr to the known initil onditions during hot fire test. For se study, SSME, s one of the most omplited, suessful nd omprehensive LPRE uilt up to now, is simulted nd the results re ompred with pulished dt. 2 Reliztion pproh for modulr simultion of LPRE he proess of modulr simultion is lssified into five mjor steps: 1) Developing modulr models for LPRE min omponents (here in MALAB Simulink); 2) Vlidting the modules; 3) Estlishing the desired LPRE numeril flow model from the tul flow digrm; 4) Developing n lgorithm for determining the sequentil solution order nd method, sed on module s in/out dt; 5) Estlishing the integrted model. Reviewing the mjor elements for different ts LPRE yles, it is found tht LPREs re generlly onstruted of seven mjor modules. hese inlude onneting pipes, omustion hmer, nozzle, preurner (gs genertor), pumps, turines nd ontroling vlves. this pper the ooling jket is lso onsidered s module therefor totl of eight mdules hve een onsidered (le 1). Some of these modules n lso e onneted to form susystem suh s turopump ssemly or thrust hmer. With modulr form of simultion, it possile to use the sme modules for other LPREs ontining similr omponenets. Here the modules re onstruted of liner/nonliner lmped prmeter stedy stte equtions. Despite frequently used lgorithms for stedy stte nlysis [81], the hmer or preurner pressure is not known, ut itself is prmeter required to e simulted. For this pupose n lgorithm is developed whih is sed on the known prmeters t min feed line enterne (i.e. oxidizer nd fuel mss flow nd pressure t engine inlet), similr to the se of testing the engine on test stnd. he solution method is sed on Newton Rphson itertive loops. For interpolting etween the required ins, the shpepreserving pieewise ui interpoltion method ws used s Mtl funtion nd showed good ury. le 1. Min modules in LPRE flow digrm Mode l/ Susystem J No zzle ipe P B P mp Pu u rine V lve P 3 se study this pper, SSME is seleted s se study. his engine is not only SLPRE ut lso RLPRE nd is mong one the most suessful LPREs ever uilt. Furthermore, due to its speil design, it hs most of the omplexities tht ll other engines might hve, nmely: using ryogeni propellnt, seprte turopump ssemlies on eh propellnt line, low nd high pressure turopumps, hydruli turine nd et. A detil desription of SSME n e found in [11]. order to model the engine, with regrd to its tul flow digrm, numeril model using the eight modules lredy disussed is prepred (Figure 1). he model is onstruted of 34 modules s desried in le 1. Eh module is sed on stedy stte liner/nonliner lumped prmeter model mthemtil eqution. 2
MAE We of onferenes 114, 21 (217) DI: 1.151/ mteonf/21711421 Figure 1. omprison etween SSME tul (left[12]) nd urrent simulted model flow digrm he required in nd produed out dt for modules is desried in le 2 to le 5 ut due to pge numer limittions, only the modules on fuel line re mentioned. he in vriles re devided into three min tgories: prmeters: onstnt in vlues (e.g. LPFP disk dimeter) nd in Figure 2 re depited y pink olor; prmeters: urves nd grphs from whih the desired vlue should e interpolted (e.g. omustion produt gs temperture whih is plotted versus propellnt mixture rtio), depited y ornge olor in Figure 2; prmeters: estimted in other loks nd will lter e given to the urrent lok s in (e.g. LPFP pump outlet pressure is n in for HPFP pump) depited y yn olor in Figure 2. le 2. LPFP turopump in/out dt LPFP urine Prmeter LPFP Shft Rottionl Speed Min Fuel jetor Pressure ooling Pssge Pressure Fuel Vpor Gs onstnt ooling Pssge het rtio LPFP urine Polytropi Effiieny ooling Pssge emperture LPFP hrteristi Mp LPFP urine Shft orque LPFP urine mss flow rte ut ut t. LPFP Pump Prmeter LPFP Shft Rottionl Speed Min Fuel jetor Pressure Fuel Density LPFP hrteristi Mp LPFP Pump Shft orque LPFP Pump mss flow rte ut ut t. le 3. MFV nd V in/out dt MFV Prmeter HPFP Pump Dishrge Pressure HPFP Pump Dishrge mss flow MFV Nominl Are Rtio Grph MFV hrottle Sitution MFV Dishrge Pressure ut t. V Prmeter MFV Dishrge Pressure PreBurners Min Fuel Supply Line V Nominl Are Rtio Grph V hrottle Sitution V Dishrge mss fllow rte ut t. 3
MAE We of onferenes 114, 21 (217) DI: 1.151/ mteonf/21711421 le 4. Fuel preurner nd omustion hmer in/out dt Fuel PreBurner Prmeter Fuel PreBurner Fuel mss flow rte Fuel PreBurner xid mss flow rte Nozzle ooling Pssge emperture inlet Nozzle ooling Pssge mss flow Nozzle ooling Pssge emperture V mss flow rte Fuel PreBurner hrot Dimeter PreBurner emperturemixure Rtio Fuel PreBurner Pressure Fuel PreBurner emperture ut ut t. omustion hmer Prmeter MV mss flow rte Fuel jetor mss flow rte HPP Boost Pump mss flow HPFP Pump mss flow emperturemixture Rtio Grph Produt gmmixture Rtio Grph Gs onstntmixture Rtio Grph omustion hmer hrot Are omustion hmer Pressure omustion hmer emperture ut ut t. le 5. Nozzle ooling jket nd FP fuel line let in/out dt Nozzle ooling Jket Prmeter MFV Dishrge Pressure Nozzle ooling Pssge Pressure Nozzle ooling Pssge Frition Grph Nozzle ooling Pssge Dishrge mss flow ut t. FP Fuel line prmeter Fuel PreBurner Pressure PreBurners Min Fuel Supply Line Nozzle ooling mss flow V mss flow Fuel PreBurner Fuel mss flow Fuel Density Feeding the Pre Burners ut ut t. 4
MAE We of onferenes 114, 21 (217) DI: 1.151/ mteonf/21711421 Figure 2. LPFP turine, pump, fuel preurner nd omustion hmer Simulink module After eh module is verified, in order to form the integrted system model, the modules should e linked together with orret logi ording to the desired engine flow digrm (Figure 3). Using given in dt nd nine initil guesses, the equtions re solved y Newton Rphson itertion method. By orret onnetion of modules, n integrted model sed on desired flow digrm n e formed. onsidering SSME s our se study, the outer lyer of the integrted Simulink model is shown in Figure 4. Figure 3. System simultion lok digrm (left); SSME simultion lgorithm (right) Figure 4. SSME integrted Simulink system simultion 5
MAE We of onferenes 114, 21 (217) DI: 1.151/ mteonf/21711421 4 Results For vlidting the suggested lgorithm nd simultion softwre, SSME RLPRE dt throttled t 19 perent of nominl opertion ondition is used from Roketdyne report [13]. For this purpose using the suggested lgorithm in Figure 3, the integrted model of the engine (ontining 34 modules) is formed in MALAB Simulink. he totl system of equtions onsisting of 11 liner/nonliner equtions re solved with Newton Rphson method. he required system level in vlues n e found in le 6. le 6. SSME System in prmeters t 19% thrust level Prmeter Fuel tnk dishrge mss flow xidizer tnk dishrge mss flow Asolute pressure t the end of the fuel tnk Asolute pressure t the end of the oxidizer Vlue 72.79 kg s 436.72 kg s 2.4 tm 6.8 tm he simultion results n e found t le 7. As it n e seen from the results, the governing equtions used for turopump system hs leded to firly good ury exept for the LPFP whih ws in lk of initil dt. he outlet pressure whih is of ourse quiet dependle on the pump performne hs een ffeted y the torque nd speed, nd the results seem to e following the expeted trend. he turine mss flow rte nlysis shows gret onvergene nd the results re stisftory. he preurner pressure re preise whih onfirm the usge of the introdued eqution sets for this element. For the omustion hmer, using EA softwre for oming the gs produt thermodynmi properties, the results do not show good preision ut using the suggested eqution for oming the gs properties from [13], the simultion results for this element re fr etter. le 7. ompring simultion results Prmeter Simultion Roketdyne [13] Error % Shft HPFP 36954.2 37354.67 1.7 rottionl HPP 31497.53 31133.36 1.17 speed, LPFP 15235.47 1586.83 3.61 (rpm) LPP 555.54 5447.11 1.7 orque, (N.m) Pump outlet pressure (tm) urine mss flow rte, m (kg s) m t PB pressure (tm) pressure (tm) HPFP 14389.5 14594.5 1.4 HPP 6489.89 635.64 2.19 HPBP 449.72 438.58 2.54 LPFP 1238.39 1327.43 6.71 LPP 235.37 2271.32 1.5 HPFP 463.92 476.61 2.66 HPP 361.1 35.62 2.99 HPBP 59.79 573.95 2.93 LPFP 16.5 17.63 8.96 LPP 3.82 3.1 2.39 HPFP 72.79 73.32.72 HPP 3.1 28.61 4.89 LPFP 15.1 15.73 4.1 LPP 79.35 78.73.79 FP 44.2 41.3.68 P 41.96 399.3.67 Exp. Gs prop. 226.39 227..27 EA 28.96 227. 23.77 6
MAE We of onferenes 114, 21 (217) DI: 1.151/ mteonf/21711421 5 onlusion A modulr simultion softwre for stedy stte simultion of RLPRE ws developed sed on MALAB Simulink. Eight generl simultion modules for simulting engine min omponents ws estlished. the urrent simultion, despite ommonly used lgorithms, the simultion is not dependnt on engine down strem prmeters. As se study, SSME s the most suessful RLPRE ever uilt, ws seleted nd the engine flow digrm ws simplified nd modulrized to 34 omponent modules. A totl of 11 liner/nonliner equtions were solved using NewtonRphson itertion method. ompring with the tul results for the engine s throttled opertion t 19 perent of the nominl thrust vlue, it is onieved tht the simultion hs n eptle verge preision of more thn 95 perent. As future work, the urrent preision n e enhned y introduing more detiled initil dt espeilly for the LPFP ssemley nd the softwre n e further verified with other engine yles. Referenes [1]. Goertz, "A modulr method for the nlysis of liquid roket engine yles," 1995. [2] K. Liu nd Y. Zhng, "A study on verstile simultion of liquid propellnt roket engine systems trnsients," 2. [3] J. M.. R. Koppel, R. Perez, J. Steelnt, P. mly, "A Pltform Stellite Modelling With EosimPro: Simultion Results," presented t the 45th AIAA/ASME/SAE/ASEE Joint Propulsion onferene & Exhiit, Denver, olordo, 2 5 August, 29. [4] F. Di Mtteo nd M. De Ros, "Stedy Stte Lirry for Liquid Roket Engine yle Design," 211. [5] X. H. P. Z. Yn, Y. Q. heng, J. J. Wu,, "System Dynmi hrteristi Simultion of Sperft Propulsion System Bsed on AMESim," Advned Mterils Reserh, vol. 6567, pp. 679683, 213 [6] A. R. J. M. Nderi, H. krimi, "Modeling And Simultion f pen yle Liquid Propellnt Engines," Journl of Siene nd Engineering, vol. Vol. 1, 213. [7]. L. L. Wei, X. Gng, D. Jing, Z. Himing, Y. Ho, "Modeling nd Simultion of Liquid Propellnt Roket Engine rnsient Performne Using Modeli," presented t the Proeedings of the 11th terntionl Modeli onferene, Versilles, Frne, Septemer 2123, 215. [8] M. hitsz, E. A. hmsei, nd H. Krimi M, "A Method for Simultion of ryogeni Liquid Propellnt Engine," Applied Mehnis nd Mterils, vol. 11116, pp. 2372376, 211. [9] D. H. H. Dieter K Huzel, Modern Engineering for Design of Liquid Propellnt Roket Engines. Wshington D, USA: Amerin stitute of Aeronutis nd Astronutis, 1992. [1] H. L. Humle, Spe Propulsion Anlysis nd Design USA: MGrwHill., 27 [11] "Spe Shuttle Min Engine rienttion," in "B984," Roketdyne Propulsion nd Power, BoeingJune 1998. [12] (Mrh, 216). www.wikipedi.om. [13] N. Dynmis, "SSME Model Dynmi hrteristis Relted to PG," Roketdyne Division Rokwel terntionl, 3th Septemer, 1973. Arevition omustion hmer LPRE Liquid Propellnt Roket Engine V ooling ontrol Vlve MFV Min Fuel Vlve J ooling Jket MV Min xidizer Vlve FP Fuel PreBurner P xidizer PreBurner FPV Fuel PreBurner Vlve PV xidizer PreBurner Vlve HPFP High Pressure Fuel uropump PB PreBurner HPP High Pressure xidizer uro Reusle Liquid Propellnt RLPRE Pump Roket Engine IG itil Guess SLPRE Stge omustion yle LPRE LPFP Low Pressure Fuel uropump hrust hmer LPP Low Pressure xidizer uro Pump 7