Scramjets or Dual Mode Ramjets for High Speed Atmospheric Flight

The lecture of the RTO-AVT-VKI course “HIGH SPEED PROPULSION: ENGINE DESIGN – INTEGRATION AND THERMAL MANAGEMENT” was given at the Von Karman Institute in September 2010 and in the Wright State University in December 2010. The present lecture was focused first on the estimation of the heat loads on a scramjet or a dual-mode ramjet. Solutions to sustain such high energy are secondly described and the lecture addresses how to combine materials, cooling techniques and system requirements. A simple exercise was proposed to the attendees as an illustrative understanding of regeneratively cooled generic scramjet flying at Mach 7. The results are based on published information, and additional details, presented to the lecturers, can be found in the references. RESUME Le stage RTO-AVT-VKI “HIGH SPEED PROPULSION: ENGINE DESIGN – INTEGRATION AND THERMAL MANAGEMENT” fut donné à l’Institut Von Karman en septembre 2010 et à l’Université Wright de Dayton (Ohio, USA) en décembre 2010. Le présent cours aborde la tenue thermique. Il est basé sur des informations publiées, et des détails supplémentaires, présentés aux personnes qui suivaient le cours, pourront être trouvés dans les références bibliographiques. Trois aspects ont été discutés, avec éventuellement quelques calculs simples de compréhension : quelles sont les charges thermiques à supporter ? comment faire pour y résister ? quelles technologies font l’objet de travaux dans le monde ? CONTEXT Scramjets or Dual Mode Ramjets for High Speed Atmospheric Flight NASA, DOD, the U.S. industry and global community have studied scramjet-powered hypersonic vehicles for over 40 years [1] [10] [22]. In a large part of the flight regime, the air-breathing mode appears to be a good possible solution for future Reusable Space Launchers (RSL). Dual-mode ramjets have been studied to propel such TSTO (Two Stage To Orbit) or Single Stage To Orbit (SSTO) vehicles. For example, in the scope of the French PREPHA program, the study of a generic SSTO vehicle led to conclusion that the best type of airbreathing engine could be the dual-mode ramjet (subsonic then supersonic combustion). Airbreathing launchers could typically use hydrogen-fuelled DMR. Less energetic fuels like hydrocarbons could also be used at a Mach number lower than 8, to take advantage of their higher density. In this case, the engine must be able to manage two different fuels. Report Documentation Page Form Approved OMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE SEP 2010 2. REPORT TYPE N/A 3. DATES COVERED 4. TITLE AND SUBTITLE Scramjet Thermal Management (Tenue thermique des superstatoréacteurs) 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) MBDA France Rond-point Marcel Hanriot, route dIssoudun 18020 Bourges FRANCE 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release, distribution unlimited 13. SUPPLEMENTARY NOTES See also ADA564620. High Speed Propulsion: Engine Design Integration and Thermal Management (Propulsion a vitesse elevee : Conception du moteur integration et gestion thermique) 14. ABSTRACT The lecture of the RTO-AVT-VKI course HIGH SPEED PROPULSION: ENGINE DESIGN INTEGRATION AND THERMAL MANAGEMENT was given at the Von Karman Institute in September 2010 and in the Wright State University in December 2010. The present lecture was focused first on the estimation of the heat loads on a scramjet or a dual-mode ramjet. Solutions to sustain such high energy are secondly described and the lecture addresses how to combine materials, cooling techniques and system requirements. A simple exercise was proposed to the attendees as an illustrative understanding of regeneratively cooled generic scramjet flying at Mach 7. The results are based on published information, and additional details, presented to the lecturers, can be found in the references. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18. NUMBER OF PAGES 30 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b. ABSTRACT unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Scramjet Thermal Management 13 2 RTO-EN-AVT-185 High speed aircraft could use hydrogen, liquid hydrocarbon (kerosene or endothermic fuels like JP7) or methane. Hypersonic military applications and associated DMR or scramjets are typically associated with liquid hydrocarbons and a maximum Mach number of 8 (missiles). For most of these applications, the scramjet is not used alone but is generally one particular operation of a dual-mode ramjet (DMR): a ramjet able to operate in subsonic combustion (for a flight Mach number between 1.5 and 6 for example) then in supersonic combustion (for a flight Mach number over 6 for example). In a supersonic combustion ramjet, while heat release is equivalent to cross section decrease, the Mach number decreases (but remains supersonic) while the pressure and the temperature increase. 1D and 3D computational tools are used in connection of testing to optimize the engine. An example is given in [13], for a supersonic combustion chamber tested under Mach 6 flight conditions for two fuelling conditions. Two main challenges are attached to scramjet or DMR: 1) To ensure a sufficient aeropropulsive balance (which could lead to particular flow-path contours and to have variable geometries). 2) To ensure sufficient thermal and mechanical strength (topic of the present lecture). foyer Nozzle Thrust : T performance sensitivity M 2 : Net Thrust = 1 = 2 – 1 M 8 : Net Thrust = 1 = 7 – 6