The French Hypersonic Research program PREPHA - Progress review

AIAA-93-5160 The French Hypersonic Research Program PREPHA: Progress Review M. Sancho, DGNDCAdSTPA, Paris, France AIANDGLR FIFTH INTERNATIONAL AEROSPACE PLANES AND HYPERSONICS TECHNOLOGIES CONFERENCE 30 NOVEMBER - 3 DECEMBER 1993 I MUNICH, GERMANY For permission to copy or republish, contact the American Institute of Aeronautics and Astronautics The Aerospace Center 370 L'Enfant Promenade, SW Washington, DC 20024-2518 THE FRENCH IIWERSONIC RESEARCH PROGRAM PREPHA : PROGRESS REVIEW by Ingenieur en chef de I'armement Michel SANCIIO program manager DGNDCACISTPA PARIS, FRANCE ABSTRACT DGA is thc executive agency which manages the program, prcpares and awards contracts. Thc Frcnch hypcrsonic rcsearch program PREPHA is sponsorcd by civil and military administrations. The technical content is dcscribed and some prcliminary results aftcr 18 months activity are givcn. 1.ORIGlN AND PROGRAM ORGANIZATION Thc main aerospace companies Aerospatiale, Dassault, Snecma, Societk curopeennc de propulsioq associated with ONERA aeronautical research center, joined to propose an integrated work program. THE 2. PROGRAM The origin of PREPHA is dcscribed in rcfcrcnces 1 and 2. To summarizc it, studics carricd out bctwecn 1987 and 1991 lcd to conclusion that : 2.1. Obiectives OF Thc main goal of this row ycars program is to study the scramjct engine and to tcst it on ground. The second one is to improve French knowledgc in numerical computations for aerodynamics and combustion, in high tempcraturc matcrials and other useful technologies, and to upgradc our cxisting test facilitics. -ultra high Mach airbreathing flight is a very challenging mattcr for long term applications, 4 - supersonic combustion ramjet is thc most intercsting cnginc for optimizcd future aihrcathing spacc transportation systcms, 2.2. Contents and urogrcss - matcrials, light wcight stnictnrcs, numerical Thc program is divided into fivc topics (scramjct, computation codcs, matcrials, vchiclcs and engines, tcst facilities), cach of them bcing divided into actions (total 30) methods arc crncial points, -basic technologics havc both civil and military applications. In 1991, thc French anthoritics decidcd to launch a rescarch and technology program, mainly focused on advanccd hypersonic propulsion, that is thc scramjet enginc. In addition the program also intends to progrcss with somc critical technologics neccssary for hypcrsonic vchiclcs. 2.2.1. Scramjct Thc six actions are forebody and inlcts, basic research on combustion, injector technology, combustion chambcr, scramjet, nozzle and aftchody. During the first ycar, a largc amount of configurations has been studicd, such as for example different forcbody shapcs (fig. I), inlets includind fixed and variable gcomctries (fig. 2), nozzles and afterbodies (fig. 3). Thc most promising ones will bc chosen for wind tunnel tests to be pcrformcd in 1994. Thc program is funded jointly by thc Ministt). of Defcnsc (DGA), thc National Space Agcncy (CNES), and Ministry of Rescarch and Tcchnology (MRT). Thc organization structure is also described in refercnces 1 and 2. Copyright C 1993 hy thc Amcrican Insliliic of Acronaulics and Astronautics, Inc., All rights rncwcd. 1 In the injection technics topic work is done on basic research likc understanding and prediction of flow mixing, flame stabilt/ation, boundary layer phcnomcna. duration and faisability of structural patis for all kinds of applicable materials like composites (ceramic, carbon, glass or metallic matrix) and intermetallics. During the first year, basic research has begun, mainly in ONERA. Different types of injectors strut concepts havc bccn studied with optimization of acrodynamics, thcrmal behaviour and flow mixing (fig. 4). Here again the two most promising havc been chosen for testing in aerothennodynamic and combustion test cells in 1994 - In most cases we try also to develop numcrical simulation methods based on test results (fig. 8 ) . 2.2.4. Vehicle and propulsion systems Basic studics on the combustion chamber are performed with CHAMOIS, a Chamber Modular for Optimization of Injection in a Scramjet. A first geomctric configuration has been chosen, based on many computation results and will be tested in Acrospatialc Subdray text cell up to Mach 6 in april 1994. The chamber definition and test installation allow configuration changes for parametric studies (fig. 5) The aim of that topic is not to define a prccise practical application, but to provide parametersnecessary for all other topics, particularly scramjet and material topics. For that we chose the most ambitious formula for technology requirements, the SSTO. From three different conccpts proposed by Aerospatiale, Dassault and Onera, one gencric veluclc was defined (fig. 9) that will be used for thc other studics. Performance loops arc computed taking into account differcnt possibilities of combined propulsion. All these results will be integratcd into thc scramjct topic allowing full test from inlet to nozzle up to Mach X in ONERA Modanc wind tunnel S4MA (fig. 6), which is the main objective of current approved program. Four engine concepts were chosen (fig. IO). Performance loops for each one arc computed to check their capability and provide parametric entries for intcgration into the generic vehicle. We intend, ncxt year, to limit thc number of these concepts. 2.2.2. Numerical methods Improvment of computational codcs is one of our prioritics. A synthcsis of Prepha codcs is prcscnted on fig. 7. Existing internal and external aerodynamic codcs are modified for Prepha applications. 2.2.5. Test facilities During the first year, we bcgan to study and apply modifications in our existing test facilities (fig. 11). Fundamental research tests on combustion are performed in ONERA Palaiseau ( A D test ccll and LAERTE laboratory), CHAMOIS combustion chamber test takcs place in Aerospatiale Subdray and final scramjet test up to Mach 8 in ONERA Modane S4 wind tunncl. For combustion codcs. main French fundamcntal research laboratorics from National Agcncy for Scientific Research (CNRS) arc involved in this topic, in closc coopcration with the five Prcpha industrial participants. All combustion physical models will be compared to results of experiment conducted in aerothermodynamics test cell in ONERA Palaiseau and in basic rescarch laboratories. In parrallel, studies on advanced measurements tcchnics bavc begun to improve the test results explanations. such as optical measurement and visualisation, laser velocimetry and tomography, gas amlysis and others. 2.2.3. Materials Improvment of materials is necessary before designing useful vehicles. Prepha supplcmcnts otlicr programs likc Hcrmes as regards particular environncment in pressure, tcmperaturc, oxydation. 2 W CW 3. CONCLUSION The Prepha program was officially launchcd in 1991 and thc first contracts awardcd in may 1992. Aftcr morc than onc ycar work, Prepha has rcached cruise speed and coopcration betwccn industry, rcsearch agcncies and laboratories, stecring and cxccutive agencies is wcll cstablished. First tcchnical rcsults begins to producc answers and next main progress stcp will be thc first run of CHAMOIS combustion chamber tcst at Mach 6 in april 1994. To conclude it is important to come back on the main fcaturcs of Prcpha : - Prcpha docs not aim at a pratical application with well dcfincd operational specification, it is purcly a rcsearch program on the supcrsonic combustion ramjct and its intcgration into a vehiclc cnabling us to get answers on the tcchnicdl feasibility of thc scramjet and its application on an airbreathing space transportation systcm. - Prepha tries to combinc harmonously tcst rcsults and computation mcthods. e - Prepha is a four year French national program but we are open to discuss on cooperation for post-Prepha activities beyond 1995. [ 1 ] B. Dcbout : Frcnch rescarch and technology programm on advanced hypcrsonic propulsion (paper AIAA 91-5003 presented on AIAA 3rd Aerospacc planes conferencc, decembcr 199 1). [ 2 ] B. Debont and C. Mathieu : French Prepha program, status rcport (papcr AIAA 92 - presentcd on AIAA 4th Acrospace planes conferencc, dcccmber 1992). 3 Fig. 1 Forebody shapes A I H INTAKE CONCEPTS FOR S I N G L E uuc'r PROPULSION 1 ---> SELECTION OF 2 DIFFERENT CONFIGURATION SERN 2 D AFTERBODY 7, - 1'1-OW COMPU'TA'I'IONS Fig. 3 ,. -- ----- SERN AXISYMETRIC AFIERBODY Lb 21) CONFIGURAIION 'IO 131: 'I'IW'ED IN 1994 Nozzle and afterbody configuration FIHST I NJ ECTO It CON C E PTS - I % : .' '..\ * .< Fig. 4 Injector optimization Fig. 5 CHAMOIS combustion chamber test ONERA MODANE S4 t ' huriier \ heater MODIFICATION FOR MACH 8 SIMULATION BL extraction \ '51 .. '-. 5ngne inlet scramjet inlet 7D nozzle' w m j e t Fig. 6 Scramjet test installation 6 scram,jet exit cooled vacuum diffuser trumps NUMERICAL METHODS Fig. 7 Numerical codes MODEL FOR C/C OXIDAfION BEHAVIOUR ASSUMPTIONS C/C CONSIDERED AS A I D POROUS MEDIUM (PROTECTED OR NOT) CONSERVATION LAWS FOR MASS SPECIES., MOMENTI .-. ..-. . 1M AND ENERGY A R E WRITTEN FOR A COMPRESSIBLE. CII~:MICAI.l.Y RIIACIING GAS I:LOW CllliMlSTRY IIASID ON KINIi'I'ICS d Fig. 8 Material behavior prediction 7 60830 JAW c t I 68030 Fig. 9 Generic vehicle design Ill'( I ,\ I1 \ 11111110.11 I S( 'l<.\bI.lt: I II . .~ . .. u0I'lit:l' ... Fig. 10 Combined propulsion concepts 8 . . v UASIC HESEAHCIIS : ONERA LAERI'E (LABORATOIRE POUR LES ECOULEMENTS REACTIFS ET LES TECIINIQUES D'ETUDES) ' IN.IK("I'ION I4,OWS hllXlN(: SIII'F:HSONl('('OMllIISI'ION Wl'l'll 112 Fig. 11 Test facilities 9