Developments in Liquid Rocket Engine Tech - Richard Cohn.pdf

Developments in Liquid Rocket Engine Technology

Dr. Richard CohnChief, Liquid Rocket Engines Branch

Propulsion Directorate

Air Force Research [email protected]

661-275-5198

Distribution A Approved for Public Release. Distribution Unlimited. PA Clearance #10439

2Air 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.


3AFRL People & Facilities

5,400 Govt 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)Distribution A Approved for Public Release. Distribution Unlimited. PA Clearance #10439

4Space and Missile R&D Building Block Process

6.1 6.2 6.3


5AFRL Propulsion Directorate

Corporate

InformationContracts

Turbine Engine

Division

Engine

Components

Gas Generators

Engine Demos

IHPTET Mgt

Energy, Power &

Thermal Division

Aircraft & Missile Power

Special Power

Thermal Management

Plasma Research

Space & Missile

Propulsion Division

Aerophysics

Analysis

Engines

Materials

Motors

Operations

Propellants

Spacecraft

Aerospace

Propulsion Office

Initiates, Plans,

Promotes and

Conducts R&D

Programs in Adv

Engine Science &

Technology

FinanceCorporate

Development

Integration &

Operations Division

Administration

Civilian Personnel

Computer Support

Facility Support

Front Office Support

As of: 25 Jun 10

WPAFBEdwards AFB

DIRECTORMr. Doug Bowers

Associate DirectorEdwards Site CC

Col(S) Mike Platt

Chief Scientist Dr. Dick River

Deputy DirectorCol Bill Hack

Mr. Dave BlasiusMr. Phil MitchellMs. Cheryl SkipperMs. Mary Donohue-Perry

Mr. John FedonMr. Bill Koop

Mr. Tom Jackson

Dr. Rick Fingers

Mr. Mike Huggins


6RZ-West Organization

INTEGRATION & OPS

DIVISION (WEST)

MR. K. VANDERDHYDE

RZO (Deputy)

FINANCE

BRANCH (WEST)

MS. RUTH DECOY

RZFB

BUSINESS

OPERATIONS

CAPT MATT

PASTEWAIT/TJ

TURNER

RZOF

INFORMATION

TECHNOLOGY

MR. CARL OUSLEY

RZOI

CHIEF OF SAFETY

MS. DEB FULLER

SE

QUALITY

ASSURANCE

TSGT TIMOTHY

ROWE

QA

EXECUTIVE

OFFICER

1ST LT ERIC MILLER

CCE

FIRST SERGEANT

TSGT CARLOS

LABRADOR

CCF (Addl Duty)

SPACE & MISSILE

PROPULSION DIVISION

MR. MIKE HUGGINS

AEROPHYSICS

DR. INGRID WYSONG

RZSA

MOTORS

CAPT KRISTEN CLARK

ENGINES

DR. RICHARD COHN

MATERIALS APPS

MAJ(S) A. DUGAS

RZSM

PROPELLANTS

DR. STEVEN SVEDJA

RZSP

SPACECRAFT

DR. JAMES HAAS

RZSS

EXPERIMENTAL DEMO

MS. JULIE CARLILE

RZSO

PAYOFF STUDIES

MR. ROY HILTON

RZST

CONTRACTS

MS. LUCY CASTEL

AFFTC/PK

ASSOC DIRECTOR

SITE COMMANDER

COL(S) MIKE PLATT

RZ

RZSRZ

DET 7

RZ (Edwards)Det 7 Other

RZSB

RZSE

As of: 1 Jun 09

Propulsion Directorate

Mr. DOUG BOWERS


7RZ-West People

Civil Service

(175)

Military

(65)

On-site

Contractors

(240)

Overall

Advanced Degrees

13% PhD

11% MS

Approx. 475 on-site personnel

RZSE

Advanced Degrees

27% PhD

36% MS

5 in Student Programs


8Edwards AFB

Edwards AFB is located about 120 miles North of LAXMap from Google Maps


9MOJAVE

BORONHWY 58

LANCASTER

AVENUE E

HIG

HW

AY

14

LA

NC

AS

TE

R B

LV

D.

14

0th

ST

RE

ET

EA

ST

RESERVATION BOUNDARY

0 5 10

SCALE IN MILES

HWY 395

ROSAMOND BLVD.

MERCURY BLVD.

RO

CK

ET

SIT

E R

OA

D

EDWARDS AIR FORCE BASE Air Force

Research

Laboratory

Site

ROGERS

DRY LAKE

ROSAMOND

DRY LAKE

AFFTC

Edwards AFB

HWY 58

D.C.


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


11

Facilities: Bench-Scale Labs


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


13

AIAAs 1st Historical Aerospace Sites (2000)

1. Rocket Site2. 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


14

AFRL Edwards Rocket Site: LiquidRocket Technology Development

Air Force Programs

Air Force Proposed

Other Programs

X-33

XRS-2200

On-Demand Launch

(RBS)

Space Vector 1

AFRL Aerospike Tech

AFRL Thrust

Cell Program

Military Space

Plane & SOV

AFRL IPD

Concept

Engine

AFRL XLR-129

Space

Shuttle

SSME

X-15

AFRL XLR-99

RL-10

Centaur Upper Stage

CL-400 Suntan

DC-X

J2X

RS 68- A/B ARES

Four Decades of Leadership in Rocket Engine Technology

AFRL HCB


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


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 6000+ psi in some components

Extremely high heat fluxes

Operate at 100% throttle during most of mission Total operational time measured in minutes


17

Comparison of Rocket and Turbojet

500,000 lbf 50,000 lbf

Power density 10X greater in rocket compared to turbojet


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


19

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

SMV/SOV

Air-to-Air Missiles

High Energy

Upper Stages

ELVs ICBMs

SLBMs Satellites

Micro-Satellites

Integrated High Payoff Rocket Propulsion Technology (IHPRPT)

Ground/Surface

Launched Missiles


20

Liquid Rocket Engine Technology Efforts

Rocket Engine Technology Demonstration Programs1. 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


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 Engine: E1 Test Stand NASA SSC, Test

014TA: Standard Start to 85%PL, (Actual 89%PL) w/

Steady State; Test Profile SA, December 15th, 2005

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 10th, 2005


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


23

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

Current SOA

High Pressure LOX/LH2

Booster

Space Shuttle Main Engine

Fuel Rich Staged Combustion

Benefits of IPD Full Flow Cycle

Successful Test Program with one set of hardware

Incorporation of large amounts of Modeling and Simulation tools

Tools drive the test process


24

2. Upper Stage Engine Technology (USET)

RL-10 Engine initially developed in the 1950s 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

All

operational

DoD

satellites

lifted by

EELV

Atlas V

Upper stage

RL10-A-4-2

Delta IV

Upper

stage

RL10-B-2

Turbopump

Assembly

Identify Issues


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 dataModels & design tools applicable to other Liquid Boost & OTV Applications

- Range of Thrust - Range of Propellants - Range of Engine Cycles


26

USET Output

Validation Turbopump

System Tool

Thrust Chamber Tools

Turbopump Tools

Modeling & Simulation

USET

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


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 integrationDistribution A Approved for Public Release. Distribution Unlimited. PA Clearance #10439

28

USET AccomplishmentsAFRL Test Stand - Facility Readiness Review (FRR)

Activation with GN2 and LN2 Complete

Hydrogen Vents, Drains, and Flarestacksystem 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

Testing to complete in FY2011

Pump Supply Line

Test Stand 2A Activation

USET Validation TPA

inside of Test Skid


29

USET Tool Improvement

(Pump Performance Methodology)

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 CavitationOptimization

Enabled Improvement of Off-Design USET Performance

Lower Test Risk

Reduced Design Iteration Late in Development

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


30

3. Hydrocarbon Boost

Hydrocarbon Boost establishes the required

tech base/knowledge base for domestic ORSC engine

Developing new Liquid Oxygen/Kerosene staged combustion engine 250k skid based brass board demo engine for simplified test stand operations

12 year development effort (2007-2019) Aerojet Prime contractor


31

Hydrocarbon Boosters: State of the Industry

Increased Life + Operability + Performance =

HC Boost Demo Will Redefine Global State-of-the-Art

270

280

290

300

310

320

330

340

350

0 200,000 400,000 600,000 800,000 1,000,00 1,200,00 1,400,00 1,600,00 1,800,00 2,000,0

Thrust (Klbf)

Isp

(V

ac)

MA -5

Atlas I/II

1963

RS -27

Delta II/III

1972

H -1

Saturn I

1961

US Technology Base

Gas Generator Cycle

RD -170

Zenit

1987

F -1

Saturn V

1967

NK -33

N -1

Never Flown Russian Technology Base

Ox -Rich Stage Combustion Cycle

RD -180

Atlas V

1999

200 400 600 800 1000 1200 1400 1600 1800 2000

270

280

290

300

310

320

330

340

350

0 200,000 400,000 600,000 800,000 1,000,00 1,200,00 1,400,00 1,600,00 1,800,00 2,000,0

Thrust (Klbf)

Isp

(V

ac)

Russian Technology Base

Ox-Rich Stage Combustion Cycle

200 400 600 800 1000 1200 1400 1600 1800 2000

US Technology Base

Gas Generator Cycle

RD-170

Zenit

1987

RD-180

Atlas V

1999

RD-191

Naro-1

2009

NK-33

N-1

Never Flown

Merlin 1C (100k)

Falcon (1&9)

2008FS-27

Delta II/III

1972

MA-5

Atlas I/II

1963

H-1

Saturn I

1961

F-1

Saturn V

1967


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


33

Vision

EngineTRL 3

Subscale /

Rig Testing

TRL 4Component

Testing

Integrated Engine

Cycle Testing (250K)

TRL 5

Systems Engineering Approach to Operational HC Engine Development

Component TRL GreenSystem TRL Purple

TRL 6

Flight weight

Engine

TRL 9Prototype Engine

Modeling, Simulation and Analysis

TRL 5


3434

Subscale Ox-Rich Preburner Assembly

LOX Inlet

Injector

Calorimeter Chamber

Diluent Chamber

L Chamber

Instrumentation Ring

Throat

Igniter


3535

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

Start transient characteristics/low-throttle operation

Subscale ORPB Rig Test

Test Objectives


36

Structural & Thermal Analysis:

Finite Element Analysis (Commercial)

Combustion device M&S design roadmap

CoDR PDR CDR

CFD Approach (Commercial)

Mixing Flow,

No Chemistry

Mixing Of Two Streams

r=r(Yi,T)

Estimate Heat

Release Profile

One Step Chemistry

-r=r(Yi,T)

pdf, Equilibrium

-r=r(f,f)

Refine Heat Release

Profile

One Step Chemistry

Multi Steps Chemistry

Reduced Mechanism

Need Test Data To

Guide CFD Model

Refine Chemistry To

Account For RP

Decomposition

Multi Steps Chemistry

Droplet Combustion (?)


37

Example of CoDR Level CFD Analysis


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-32207 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


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


40

3GRB Roadmap

FY 09 FY 10 FY 11 FY 12 FY 13 FY 14 FY 15

Task Order 1Aerojet

Task Order 1Pratt and Whitney

Rocketdyne

Task Order 1WASK

Initial Risk Reduction

Component Demonstration

Vision Engine

Development

Vision Engine

Development

Vision Engine

Development

Initial Risk Reduction

Task Order 2Contractor TBD



IDIQ competition

Task Order competition

Task Order competition

3 Awards Task Order 1Complete

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

1 Awards Task Order 3

Further Risk Reduction and ValidationDistribution A Approved for Public Release. Distribution Unlimited. PA Clearance #10439

41

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

Aerojet Vision Engine Overview

Fuel Inlet

LOX Inlet

OX Isolation

Valve

Preburner

Fuel Cooling Manifolds


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 PreburnerNo moisture / contaminatesEliminates 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


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


44

Drive Towards Model Driven Development

There is a need to improve 30-40 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)


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-LCH4 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


46

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

Temperature uniformity

Concentration uniformity

Flow uniformity

Injector Diluent Injection

Low MR

High T

Mixing

Tu

rbin

e

Goal: T uniformity

High MR

Low T

Supercritical Fluid Flows

Multiple Jets/Jet Systems interaction

3D configuration constrained

Extreme Pressure

High J

High RrhoReacting flows

Subsonic Flows

Penetration

Vortex Generation

Well Understood, Extensive Literature

Available

Themis Simulations

Supersonic Flows(Ramjet/ Scramjet)

AtomizationAeration of JetsResidence TimeWeber Number Relations

JICF Literature

Not capable of

comparison in

a cold flow

experiment


47

Preburner Mixing ProcessesMultiple 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

Incre

asin

g r

ele

van

ce

Decre

asin

g a

ccess


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

RP-1

Fuel 1

Fuel 2

Fuel 3

C* RP-1

C* Fuel 1

C* Fuel 2

C* Fuel 3


49

Improve Current Fuels

RP-1, Standard

GradeTS-5 RP-2, Advanced

Grade

Led development of new grade of rocket propellant


50

Thermal ManagementTranspiration 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


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


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


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


Developments in Liquid Rocket Engine Tech - Richard Cohn.pdf

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