S. Heister, W. Anderson School of Aeronautics & Astronautics

1. Rolls-Royce University Technology Center in High Mach Propulsion – Year 1 Review and Status Update I. Mudawar, P. Sojka School of Mechanical Engineering S. Heister, W. Anderson School of Aeronautics & Astronautics

2. Outline • UTC Overview & Year 1 Goals – Heister • Fuel/Air HEX Project Status – Mudawar • Supercritical Fuel Injection Project Status – Sojka • Afterburner Cooling Project Status – Anderson • Summary & Year 2 Plans - Heister

3. Senior UTC Personnel • Dr. Steve Heister, UTC Lead, propulsion, two-phase flows, engine cycles • Dr. Bill Anderson, combustors, fuel stability • Dr. Issam Mudawar, high heat-flux heat transfer • Dr. Paul Sojka, supercritical “atomizer” design & spray characterization • Dr. Jay Gore, IR spectroscopy • Mr. Scott Meyer, Senior Engineer, facilities & instrumentation • Ms. Melanie Thom (Baere Aerospace Consulting): over 15 years experience in fuel systems

4. Collaborators & Students in UTC • Fuel/air HEX project • Mr. John Tsohas, M.S. student • Mr. Neal Herring, Ph.D. student • Mr. Tim Kibbey, M.S. student and Rolls-Royce Fellowship recipient • Mr. Adam Finney, undergraduate student • A/B cooling project: • Mr. Tom Martin, M. S. student and Ross Fellowship recipient • Mr. Eric Briggs, M. S. student • Supercritical fuel injection project: • Mr. Greg Zeaton, M. S. student • Mr. Omar Morales, MARC/AIM program

5. High Mach Propulsion UTC 5 Year Plan Two-phase Fuel Injection Design injector(s) for two-phase fuel mixture flow into combustor • Test at least two injector designs to develop data base for mass-driven spray formation • Develop design models to treat mass-transfer driven spray formation • Predict mean drop size and drop size distribution in terms of atomizer operating conditions, nozzle geometry, and fuel physical properties • Build on existing effervescent atomizer model development • Include influence of fuel vaporization/cracking, which can produce liquid/vapor mixture • Develop design models to treat mass-transfer driven spray evolution • Predict patternation, cone angle, entrainment of surrounding air, and penetration • Build on existing effervescent atomizer model development (effervescent Diesel injection) • Eventually include vapor distribution as well as liquid distribution

6. 3.Supercritical Fuel (SCF) Injection Project Status

7. Supercritical Fluid (SCF) Injection Experiment Goal • Identify performance limitations for SCF injection and develop design guidelines for future high-Mach engines • A literature review of previous supercritical fluid injection studiessuggests fuel superheat, atomizer geometry, and gas/fluid density ratio are the key variables that effect • “Spray” cone angle • Patternation • “Spray” momentum rate distribution

8. SCF Injection – Fluid Selection • Jet fuel ruled out for initial experiments • HOQ is engineering approach to decision making • Surrogate “fuel” selected based on human factors and functional performance

9. SCF Injection – Fluid Selection • CO2 selected as surrogate “fuel” for first experiments • Relatively safe, inert, non-toxic • Inexpensive, readily available • Supercritical thermodynamic and transport properties are already well defined • Non-combustible so no need to redesign existing spray apparatus • Tc “low” so existing apparatus can be used

10. Baseline Injector and Preliminary Results

11. SCF Injection – Baseline Pressure Swirl Injector • Pressure swirl atomizer selected as baseline configuration for evaluation • Larger cone angles (better distribution of fuel mass in the combustion chamber) than demonstrated in previous experiments using plain orifice injectors with SCF’s • Injector geometry is easily modified to obtain desired spray characteristics

12. SCF Injection- Baseline Pressure Swirl Injector Design

13. SCF Injection - Preliminary flow visualizations • H2O-in-air (1) and H2O-in-H2O (2) flows demonstrate the influence of density ratio on spray evolution • A density ratio similarto H2O-in-H2O (near unity) will be present when SCF experiments are performed (2) (1) 9.2 g/s 9.2 g/s

14. SCF Injection - Preliminary flow visualization • An overall decrease in cone angle with increased density ratio was observed

15. SCF Injection - Experimental apparatus • Test vessel • CO2 supply system • Air supply system • DAQ system

16. SCF Injection – Test vessel • Originally used for Diesel injection • Recently upgraded to withstand pressures of 1500 psi (10.3 MPa) • Reconfigured for supercritical CO2 operation (O-rings, supply lines, etc.) Injector Windowed chamber

17. SCF Injection – CO2 supply system

18. SCF Injection – Co-flow air supply system

19. SCF Injection - Test rig PID heater controls CO2 heater Test vessel Air heater Metering valve Optical table Gas booster

20. SCF Injection – Test rig Dome regulator Co-flow air manifold Coriolis flow meter Test vessel TC probe

21. SCF Injection - DAQ & control SCXI interface Control output panel Analog input panel TC panel

22. SCF DAQ – optical patternator • Optical patternator developed at Purdue

23. SCF DAQ – Momentum rate probe • Technique refined at Purdue over the last ten years • Characterizes spray penetration via force balance • To be installed in test vessel

24. SCF Injection – Overview of system capabilities • Heat and pressurize CO2 above its critical T and p and inject into ambient environment whose p and T exceed critical CO2 values • Operate at any combination of p and T above CO2 critical values • Obtain shadowgraphs of spray cone angle • Uncertainty: +/-5 % • Obtain mass distribution data • Uncertainty: +/-0.5% • Obtain momentum rate data for spray penetration • Uncertainty: +/-1%

25. SCF Injection – Status • Facilities near completion • waiting on accumulator (to damp injection pressure pulsations) • TRR next week • DAQ software optimization • Configure optics • SCF experiments will begin by the end of January 2004

26. Gearing Status • Leveraging of UTC funds is a primary goal • Current Status • NASA MSFC “Risk Reduction for the ORSC Cycle” • ~ $0.5M w/ ~ 1/3 focused on thermal management • NASA GRC “Flow Boiling Critical Heat Flux in Reduced Gravity” (~$0.5M) • RR/AADC Industrial Affiliates Fellowship for Tim Kibbey • Purdue Ross Fellowship for Tom Martin • U/G Honors thesis project Adam Finney • MARC/AIM summer fellowship for Omar Morales • AFOSR MURI in Hypersonic Transition

27. Summary – High Mach UTC • Schedule on track to fulfill Year 1 goals • Research team in place • Fuel Thermal Management Lab nearly complete • Facility mods to spray diagnostics lab nearly complete • Gearing/leveraging efforts already successful, future efforts to explore projects with AFRL and/or NASA GRC