Developments in Liquid Rocket Engine Technology

Transcription

1 Developments in Liquid Rocket Engine Technology Dr. Richard Cohn Chief, Liquid Rocket Engines Branch Propulsion Directorate Air Force Research Laboratory

2 Air Force Materiel Command MISSION Deliver war-winning... - Technology - Acquisition - Test - Sustainment... expeditionary capabilities to the warfighter Air Force Research Laboratory Mission: Leading the discovery, development and integration of affordable warfighting technologies for America's aerospace forces. 2

3 AFRL People & Facilities 5,400 Gov t Employees 3,800 On-site Contractors 10 Major R&D sites across US 40 Locations around the World 10 Technical Directorates Air Vehicles (RB) Directed Energy (RD) Human Effectiveness (RH) (711 HP Wing) Information (RI) Space Vehicles (RV) Munitions (RW) Materials & Manufacturing (RX) Sensors (RY) Propulsion (RZ) AF Office of Scientific Research (AFOSR) 3

4 Space and Missile R&D Building Block Process

5 AFRL Propulsion Directorate Associate Director Edwards Site CC Col(S) Mike Platt DIRECTOR Mr. Doug Bowers Deputy Director Col Bill Hack Chief Scientist Dr. Dick River Corporate Development Corporate Information Finance Contracts Ms. Mary Donohue-Perry Ms. Cheryl Skipper Mr. Phil Mitchell Mr. Dave Blasius Aerospace Propulsion Office Initiates, Plans, Promotes and Conducts R&D Programs in Adv Engine Science & Technology Mr. Tom Jackson Turbine Engine Division Engine Components Gas Generators Engine Demos IHPTET Mgt Mr. Bill Koop Space & Missile Propulsion Division Aerophysics Analysis Engines Materials Motors Operations Propellants Spacecraft Energy, Power & Thermal Division Aircraft & Missile Power Special Power Thermal Management Plasma Research Dr. Rick Fingers Integration & Operations Division Administration Civilian Personnel Computer Support Facility Support Front Office Support Mr. John Fedon Mr. Mike Huggins Edwards AFB WPAFB As of: 25 Jun 10 5

6 RZ-West Organization RZ Propulsion Directorate Mr. DOUG BOWERS ASSOC DIRECTOR SITE COMMANDER COL(S) MIKE PLATT RZ DET 7 RZS SPACE & MISSILE PROPULSION DIVISION MR. MIKE HUGGINS RZO (Deputy) INTEGRATION & OPS DIVISION (WEST) MR. K. VANDERDHYDE RZFB FINANCE BRANCH (WEST) MS. RUTH DECOY CCE EXECUTIVE OFFICER 1ST LT ERIC MILLER CCF (Add l Duty) FIRST SERGEANT TSGT CARLOS LABRADOR CHIEF OF SAFETY MS. DEB FULLER QUALITY ASSURANCE TSGT TIMOTHY ROWE SE QA RZSO EXPERIMENTAL DEMO MS. JULIE CARLILE RZSP PROPELLANTS DR. STEVEN SVEDJA RZSS SPACECRAFT DR. JAMES HAAS PAYOFF STUDIES MR. ROY HILTON RZST RZSA AEROPHYSICS DR. INGRID WYSONG MOTORS CAPT KRISTEN CLARK ENGINES DR. RICHARD COHN MATERIALS APPS MAJ(S) A. DUGAS RZSB RZSE RZSM BUSINESS RZOF OPERATIONS CAPT MATT PASTEWAIT/TJ TURNER INFORMATION TECHNOLOGY MR. CARL OUSLEY RZOI AFFTC/PK CONTRACTS MS. LUCY CASTEL Det 7 RZ (Edwards) As of: 1 Jun 09 Other 6

7 RZ-West People Overall Advanced Degrees 13% PhD 11% MS Military (65) Civil Service (175) On-site Contractors (240) Approx. 475 on-site personnel RZSE Advanced Degrees 27% PhD 36% MS 5 in Student Programs 7

8 Edwards AFB Edwards AFB is located about 120 miles North of LAX Map from Google Maps 8

9 140th STREET EAST HIGHWAY 14 LANCASTER BLVD. ROCKET SITE ROAD Edwards AFB MOJAVE HWY 58 BORON D.C. EDWARDS AIR FORCE BASE ROSAMOND BLVD. AFFTC ROGERS DRY LAKE MERCURY BLVD. Air Force Research HWY 58 Laboratory Site HWY 395 ROSAMOND DRY LAKE RESERVATION BOUNDARY AVENUE E SCALE IN MILES LANCASTER 9

10 High Thrust Facilities NINETEEN LIQUID ENGINE STANDS TO 8,000,000 LBS THRUST THIRTEEN SOLID ROCKET MOTOR PADS TO 10,000,000 LBS THRUST 10

11 Facilities: Bench-Scale Labs 11

12 History 1939 Rocket research begins at Power Plant Lab, Wright Field OH 1947 Edwards AFB selected for rocket testing 1959 Rocket scientists move from WPAFB to Edwards 1997 AF labs consolidated into AFRL Key Accomplishments Saturn V F-1 engine development Minuteman ICBM silo basing XLR-129 engine (for Shuttle main engine) Peacekeeper ICBM development Missile defense interceptor HOVER tests Titan IV solid rocket motor upgrade RS-68 engine for Delta IV EELV 12

13 AIAA s 1 st Historical Aerospace Sites (2000) 1. Rocket Site 2. Aerojet Pasadena, CA 3. Goddard First Auburn, MA 4. Dutch Flats San Diego, CA 5. Tranquility Base 6. Huffman Prairie, OH and Kitty Hawk, NC Helped to Advance the Arts, sciences and technology of aeronautics and astronautics, and promoted the professionalism of those engaged in these pursuits. -AIAA 13

14 AFRL Edwards Rocket Site: Liquid Rocket Technology Development On-Demand Launch (RBS) RS 68- A/B ARES Military Space Plane & SOV Air Force Programs Air Force Proposed Other Programs Space Vector 1 DC-X Centaur Upper Stage J2X X-33 Concept Engine AFRL HCB AFRL IPD AFRL Thrust Cell Program XRS-2200 SSME Space Shuttle RL-10 X-15 AFRL Aerospike Tech AFRL XLR-129 AFRL XLR-99 CL-400 Suntan Four Decades of Leadership in Rocket Engine Technology 14

15 Key Rocket Parameters Key components of rocket engines Main Thrust Chamber Most catastrophic failures Preburner/Gas Generator Most tech challenges, harshest environment Turbopump Most likely to delay development, increase costs Booster Engines Booster stages provide initial thrust to lift vehicles off the launch pad Booster engines require high thrust Flow-rates can exceed 1000 lbs/s of propellant F-1 engine flow-rate ~650 gal/s 1.5 Swimming Pools/minute Upper Stages Final thrust to transfer orbit Moderate thrust, high performance requirements Critical parameters for rockets include Specific Impulse Thrust to weight Throttle Operability Reusability Reliability 15

16 Differences between Rocket & Jet Engine Rockets use pure oxygen as oxidizer Operate at significantly hotter combustion temperatures Pumps need to operate at cryogenic conditions Oxygen Blanching Oxygen ignition of materials Rockets may use liquid hydrogen as a fuel Extreme cryogenic conditions Hydrogen embrittlement Potentially very high pressures Can exceed psi in some components Extremely high heat fluxes Operate at 100% throttle during most of mission Total operational time measured in minutes 16

17 Comparison of Rocket and Turbojet 500,000 lbf 50,000 lbf Power density 10X greater in rocket compared to turbojet 17

18 Liquid Engine Branch Current Objectives Technology focused Develop the technologies needed to develop next generation of flight liquid rocket engines Do not develop a solution to a particular point design but attempt to increase design space Do develop integrated technology demonstrator engines Tools are a critical part of that mission Systems engineering approach Both in execution and selection of technology to develop Current focus Reusable Boost Stage Expendable Upper Stage Future focus Reusable upper stage 18

19 Integrated High Payoff Rocket Propulsion Technology (IHPRPT) Joint government and industry effort focused on developing affordable technologies for revolutionary, reusable and/or rapid response military global reach capability, sustainable strategic missiles, long life or increased maneuverability spacecraft capability and high performance tactical missile capability ELVs ICBMsSLBMs Satellites Micro-Satellites SMV/SOV High Energy Upper Stages Air-to-Air Missiles Ground/Surface Launched Missiles 19

20 Liquid Rocket Engine Technology Efforts Rocket Engine Technology Demonstration Programs 1. IPD (Lox/LH2 Booster) 2. USET (Lox/LH2 Upper Stage) 3. Hydrocarbon Boost (Lox/RP-2 Booster) 4. 3GRB (Lox/LCH4 Booster) Core Technology Efforts Drive towards Modeling and Simulation Most common conference to present programs JANNAF ITAR restrictions It is open to people from academia Must be a US citizen 20

21 1. Integrated Powerhead Demo (IPD) Joint program between AF, NASA, and Industry Supports sortie-like launch for Operationally Responsive Space (ORS) Payoffs: 200 Mission Life (20X improvement) 100 MTBOH First known full scale demonstration of Full Flow Staged Combustion Cycle in the World! IPD Ground Demonstrator Engine installed in E1 Complex Cell 1 IPD Ground Engine: E1 Test Stand NASA SSC, Test 013TA: Standard Start to 80%PL, 87%PL w/ Short Hold; Test Profile RA, November 10 th, 2005 IPD Ground Engine: E1 Test Stand NASA SSC, Test 014TA: Standard Start to 85%PL, (Actual 89%PL) w/ Steady State; Test Profile SA, December 15th,

22 IPD Program IPD program sought to improve the nations technological capability in Liquid Hydrogen/Liquid Oxygen (LH2/LOX) booster engines Design began by examining the failure modes of the SSME Sought to eliminate these failures through the use of a new engine cycle Full Flow Staged Combustion Program executed by team consisting of: AFRL NASA Rocketdyne (now Pratt & Whitney Rocketdyne) Aerojet 22

23 Benefits of IPD Full Flow Cycle Current SOA High Pressure LOX/LH2 Booster Space Shuttle Main Engine Fuel Rich Staged Combustion Benefits Provided Reduced Turbine temperatures Improve turbine life and increases reliability Eliminates of two criticality 1 failure modes Turbopump interpropellent seal Heat exchanger to pressurize propellant tanks. Thermally gentle start sequence increases turbine life Successful Test Program with one set of hardware Incorporation of large amounts of Modeling and Simulation tools Tools drive the test process 23

24 2. Upper Stage Engine Technology (USET) RL-10 Engine initially developed in the 1950 s and first flew in 1961 RL-10 engine is currently used on both EELV AFRL USET program seeks to allow the creation and transition of a modern upper stage engine Focus on developing critical tools Two contractor teams Aerojet Northrop Grumman Delta IV Upper stage RL10-B-2 All operational DoD satellites lifted by EELV Turbopump Assembly Identify Issues Atlas V Upper stage RL10-A

25 USET Objective Objective: Develop and demonstrate the next generation Model Driven Design (MDD) tools on an upper stage engine component Selected Turbopump Approach: Link commercial design tools with rocket specific empirical data, rocket specific material & propellant libraries, and user defined functions Replace targeted legacy design tools with physics based tools Enable Multi-Disciplinary Models, Time Accurate Solutions & Interconnected Models Reduced design time, more design iterations Higher fidelity analysis earlier in process Multi-disciplinary optimization Use Tools to design validation turbopump assembly Validation: provide sealed envelope predictions to compare with test data Models & design tools applicable to other Liquid Boost & OTV Applications - Range of Thrust - Range of Propellants - Range of Engine Cycles 25

26 USET Output System Tool Thrust Chamber Tools Turbopump Tools USET Modeling & Simulation Validation Turbopump Tools Pump and Inductor Performance Cavitation Integrated Vibration Tool Bearings Turbine Performance Axial Thrust Critical Fits Clearances Transient Engine Start Margin Linked Coolant Combustion System Sizing Tool 26

27 USET Validation Turbopump Challenges Design and Fabrication of Highly Instrumented Pump Over 100 measurements Full shaft position measurement system Pump has arrived at AFRL for test stand integration 27

28 USET Accomplishments AFRL Test Stand - Facility Readiness Review (FRR) Activation with GN2 and LN2 Complete Hydrogen Vents, Drains, and Flarestack system upgraded to comply with recent changes in NFPA code Successfully passed Facility Readiness Review (FRR) Facility permitted to load Hydrogen First LH2 loaded on 2 Feb 10 Test Stand 2A Activation Testing to complete in FY2011 USET Validation TPA inside of Test Skid Pump Supply Line 28

29 USET Tool Improvement (Pump Performance Methodology) USET Improvement 3-D CFD Verification of Design Performance CFD Based Optimization Cavitation Performance Optimization Assessment of Off-Design Stability and Performance Early in Design Process Description Enables 3-D Pump Component Design & Performance Analysis Early in Development CFD Based Verification of Pump Efficiency, Head Coefficient, and Cavitation Current Methodology Meanline Empirical Design Limited CFD Late in Design Process Impact Better Performance Verification Earlier in Design Process (Fidelity Forward) Enabled USET Cavitation Optimization Enabled Improvement of Off-Design USET Performance Lower Test Risk Reduced Design Iteration Late in Development 29

30 3. Hydrocarbon Boost Developing new Liquid Oxygen/Kerosene staged combustion engine 250k skid based brass board demo engine for simplified test stand operations 12 year development effort ( ) Aerojet Prime contractor Hydrocarbon Boost establishes the required tech base/knowledge base for domestic ORSC engine 30

31 Isp (Vac) Hydrocarbon Boosters: State of the Industry NK-33 NK -33 N-1 N -1 Never Flown Never Flown Merlin 1C (100k) Falcon (1&9) 2008 RS -27 FS-27 Delta II/III Delta II/III H-1 H -1 Saturn I Saturn I RD-191 RD-180 RD-170 RD -180 RD -170 Naro-1 Atlas V Zenit Atlas V Zenit Russian Russian Technology Technology Base Base Ox-Rich -Stage Rich Stage Combustion Cycle MA -5 Atlas I/II MA Atlas I/II 1963 FF-1 Saturn Saturn VV US Technology Base US Technology Base Gas Gas Generator Generator Cycle Cycle , , , ,000 1,000, ,200, ,400, ,600, ,800, ,000, Thrust (Klbf) Increased Life + Operability + Performance = HC Boost Demo Will Redefine Global State-of-the-Art 31

32 Program Objectives Develop a 250K-lbf thrust, oxidizer-rich staged combustion cycle LOX/Kerosene Liquid Rocket Engine Show scalability of technology up to very large thrust levels Develop technology to meet operability objectives Baseline fuel is advanced rocket grade kerosene Demonstrate goal achievement through testing and analysis Isp Thrust to Weight Failure Rate Production Costs Throttleability Mean Time Between Overhauls Mean Time Between Replacement 32

33 Systems Engineering Approach to Operational HC Engine Development Modeling, Simulation and Analysis Vision Engine TRL 3 Subscale / Rig Testing TRL 4 Component Testing TRL 5 Integrated Engine Cycle Testing (250K) TRL 5 Component TRL Green System TRL Purple Flight weight Engine TRL 9 Prototype Engine TRL 6 33

34 Subscale Ox-Rich Preburner Assembly Instrumentation Ring Calorimeter Chamber Throat Injector LOX Inlet Igniter Diluent Chamber L Chamber 34

35 The objectives of the test are to provide validation data for the tools used to design the hardware and evaluate the operation of the hardware. For each injector design evaluate: Combustion performance via axial energy release distribution Combustion stability characteristics High-frequency transverse modes Chug & longitudinal modes Injector face, acoustic cavity, & chamber wall thermal compatibility Steady-state temperature uniformity of preburner exhaust gas Ignition characteristics Subscale ORPB Rig Test Test Objectives Start transient characteristics/low-throttle operation 35

36 Combustion device M&S design roadmap CFD Approach (Commercial) CoDR PDR CDR Mixing Flow, No Chemistry Mixing Of Two Streams Estimate Heat Release Profile One Step Chemistry Refine Heat Release Profile One Step Chemistry Multi Steps Chemistry Refine Chemistry To Account For RP Decomposition Multi Steps Chemistry r=r(yi,t) -r=r(yi,t) pdf, Equilibrium -r=r(f,f ) Reduced Mechanism Need Test Data To Guide CFD Model Droplet Combustion (?) Structural & Thermal Analysis: Finite Element Analysis (Commercial) 36

37 Example of CoDR Level CFD Analysis 37

38 4. 3GRB Advancement of the state of the art Innovative cycles/ component technologies Pursue IHPRPT Hydrocarbon Boost Phase III and Operability Goals Fuel Choice Rocket Grade Methane MIL-PRF is the baseline fuel Methane has high potential as fuel for booster stage rocket engines Database and experience on pump fed methane engines is lacking in US AFRL to leverage existing pressure fed activities (NASA) Develop rocket engine components Component and/or breadboard validation in laboratory environment No integrated demonstration 38

39 Program Objectives Develop component technology for a high performance next generation LOX/LCH4 liquid rocket engine Show scalability of technology up to very large thrust levels Develop technology to meet operability objectives Baseline fuel is advanced rocket grade methane Demonstrate goal achievement through testing and analysis Isp Thrust to Weight Failure Rate Production Costs Throttleability Mean Time Between Overhauls Mean Time Between Replacement 39

40 3GRB Roadmap Task Order 1 Aerojet Task Order 1 Pratt and Whitney Rocketdyne Task Order 1 WASK Task Order 2 Contractor TBD Task Order 2 Contractor TBD FY 09 FY 10 FY 11 FY 12 FY 13 FY 14 FY 15 IDIQ competition Vision Engine Development Vision Engine Development Vision Engine Development Initial Risk Reduction Initial Risk Reduction 3 Awards Task Order 1 Complete Task Order competition Trade studies Vision engine development Technology Identification Risk reduction Plan 2 Awards Task Order 2 Initial Risk Reduction -- In source selection Mitigate critical risks identified in TO 0001 through M&S Task Order competition Task Order 3 Contractor TBD Component Demonstration 1 Awards Task Order 3 Further Risk Reduction and Validation 40

41 Aerojet Vision Engine Overview Staged Combustion Cycle Low Preburner Gas Temperature Assures Long Life Multiple Thrust Chamber Assemblies Small TCAs improve High Frequency Combustion Stability Center of Mass Pulled Close to Vehicle Interface Small TCAs Lower Development and Test Costs Compact TPA Preburner Fuel Inlet LOX Inlet OX Isolation Valve Fuel Cooling Manifolds 41

42 PWR Vision Engine Expander-Heat Exchanger Cycle (Ex-Hex) HEX reduces system pressures Enables higher Pressure Ratio turbine Reduces heat required to run cycle Significantly reduces Turbopump power Ex-Hex Eliminates Preburner No moisture / contaminates Eliminates drying / flushing Significantly reduces Ground-Ops Low CH4 Hot Gas Temp Reduced hot gas system complexity Benign fluid environment Improved turbine drive system life Lower Engine pressures Existing test facility infrastructure 42

43 WASK Vision Engine Staged Combustion Cycle Low Preburner Gas Temperature Assures Long Life Modular engine design Small TCAs Lower Development and Test Costs Altitude compensating nozzle Innovative TPA Eliminates boost pumps Single shaft 43

44 Drive Towards Model Driven Development There is a need to improve year old modeling, simulation, & analysis (MS&A) tools Existing tools old and empirically based and require hundreds of tests Industry losing grey beards and thus design and analysis capability Could not handle new technologies like hydrostatic bearings Current and future computational capabilities allow use of physics-based tools to supplement testing Testing drives the cost of rocket programs Necessary Need to be smart Test Driven Development (TDD) Model Driven Development (MDD) 44

45 Preburner Research In-House projects within RZSE Research needs identified to support external efforts Exploratory Gain a more fundamental understanding of design space Themis High pressure hydrocarbon propellants LOX-RP, LOX-LCH 4 Staged combustion cycles Focus on Ox-Rich Preburner Highest component risk to Hydrocarbon Boost effort Gain understanding of preburner environment Lack of basic understanding Not an optimization or demonstration of a single design Encompassing approach Not a single experiment or facility Both experiments and CFD Water visualization, cryogenic cold flow, hot fire testing Provides early validation data for Hydrocarbon Boost 45

46 Turbine Preburner Research Focus Combustion devices are focus Preburner is first priority Configuration of interest is significantly different than typical rocket hot gas devices Combustion device requires good mixing High density diluent injection Multiple flush ports injecting the fluid Simplification of geometry results in JICF configuration Jet-In-Crossflow (JICF) Available literature is extensive Most research has been done at academia Understanding at relevant environment and integrated configuration is low Injector Low MR High T JICF Literature Supersonic Flows (Ramjet/ Scramjet) Atomization Aeration of Jets Residence Time Weber Number Relations Diluent Injection Mixing Temperature uniformity Concentration uniformity Flow uniformity Subsonic Flows Penetration Vortex Generation Goal: T uniformity High MR Low T Themis Simulations Supercritical Fluid Flows Multiple Jets/Jet Systems interaction 3D configuration constrained Extreme Pressure High J High R rho Reacting flows Well Understood, Extensive Literature Available Not capable of comparison in a cold flow experiment 46

47 Increasing relevance Decreasing access Preburner Mixing Processes Multiple Confined Transverse Jets Understand mixing of LOX with combustion gases From transverse jet literature Importance of entrainment in governing jet trajectory Scaling laws, confined and unconfined Phased research process Water-visualization facility Explore mixing efficiency and scaling laws for relevant geometry Low-speed variable gas facility Employ different gases to achieve relevant density ratio and mass flow ratio regime High-pressure cold-flow facility Liquid N2 injection into He/Ar gas Supercritical fluid mixing phenomena (dilatation, transport property variations, etc.) Hot-fire test facility Sub-scale preburner configurations Explore combustion/mixing interactions Tools Experimental: LDV, PLIF, flow visualization, PIV, temperature and pressure sensors Computational: CFD and linear stability analysis 47

48 High Performance Hydrocarbon Fuels Develop and transition new fuels Feedback to chemists to improve fuel performance Tailor fuel properties Density Energy Vapor Pressure Thermal Stability Energy density of advanced synthetic fuels offers potential for: Use of advanced fuels as additives to improve performance for specialized missions Improved performance for volume constrained applications C* RP-1 C* Fuel 1 C* Fuel 2 C* Fuel 3 RP-1 Fuel 1 Fuel 2 Fuel 3 48

49 Improve Current Fuels RP-1, Standard Grade TS-5 RP-2, Advanced Grade Led development of new grade of rocket propellant 49

50 Thermal Management Transpiration Cooling AFRL in a joint program with Northrop- Grumman and Rolls Royce Liberty Works performed some of the first experiments examining transpiration cooling in a rocket engine environment Utilized several Lamilloy samples to determine applicability for rocket engine applications Lamilloy currently in use for turbine applications First application in rocket environment Seven months from concept initiation to program completion Demonstrated feasibility of using Lamilloy Need to design specifically for rocket engine applications Within experience base Sample Lamilloy Sheet Test Section 50

51 Combustion Instabilities Combustion Instabilities are a key risk to any rocket engine development program Can be extremely destructive and can destroy the engine and the test stand Complex interaction between many phenomena 51

52 Materials Research Spearheaded development of Mondaloy, a new, high strength, oxygen compatible metal Spearheaded development of nano-aluminum which has greater strength than typical aluminum alloys Bulging indicates ductile failure mode In both std and NP Al 52

53 Conclusions AFRL/RZS is leading the development of the next generation of rocket engine technology Focused efforts examining Cryo-Boost, HC Boost, and Upper Stage Rocket Propulsion Aggressive goals lead to unique vision engines Tool development is crucial Developing the critical demonstration programs as well as the key underlying technologies Improving Modeling and Simulation Tools essential for the next stage in rocket engine development 53