Developments in Liquid Rocket Engine Technology in Liquid Rocket... · Developments in Liquid...

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

mailto:[email protected]

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.


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

4

Space and Missile R&D Building Block Process

6.1 6.2 6.3


5

AFRL 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


6

―RZ-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 (Add’l 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


7

RZ-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


8

Edwards AFB

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


9

MOJAVE

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


http://www.pr.afrl.af.mil/images/50Yrs_4x6.jpg

13

AIAA’s 1st 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


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

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

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

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


http://en.wikipedia.org/wiki/Image:USS_Badger_(FF-1071)_Launching_Harpoon.jpg

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


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 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

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 data

Models & 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 Cavitation

Optimization

– 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 – Green

System 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 1—Complete

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 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


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 Rrho

•Reacting flows

•Subsonic Flows

•Penetration

•Vortex Generation

Well Understood, Extensive Literature

Available

Themis Simulations

•Supersonic Flows

(Ramjet/ Scramjet)

•Atomization

•Aeration of Jets

•Residence Time

•Weber 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 Technology in Liquid Rocket... · Developments in Liquid...

Documents

Transcript of Developments in Liquid Rocket Engine Technology in Liquid Rocket... · Developments in Liquid...