April 4 - 5, 2000

at Lewis FieldGLENN RESEARCH CENTER

Aero-Space Propulsion Simulation and Modeling

Dr. John K. Lytle

Chief, Computing and Interdisciplinary Systems Office

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Provide next generation design tools and experimental aircraft to increase design confidence, and cut the development cycle time for aircraft in half.

NASA Goals Directly Supported by Simulation and Modeling

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• High Fidelity, Physics-based Simulations•Combustion•Turbomachinery• Aeroelasticity• Probabilistic Methods• Full System

• Virtual Design Environment, Life Cycle Simulation

Outline

Advanced Space Transportation Program (MSFC)

High Performance Computing and Communications Program (ARC)

Intelligent Synthesis Environment Program (LaRC)

Intelligent Systems Program (ARC)

Information Technology R&T Base Program (ARC)

Aero-Space Propulsion and Power R&T Base (GRC)

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Fuel Nozzle Flow

Cold and Hot Isotherm Interactions

Midplane Temperature Contour

Midplane Total Pressure Contour

The National Combustion Code is an integrated system of computer codes that takes advantage of solid modeling and automated meshing of complex geometries.

The National Combustion Code uses unstructured meshes and parallel computing. Physical models include: a turbulence module containing the nonlinear k-epsilon models; conventional reduced chemical kinetics or the Intrinsic Low Dimensional Manifold (ILDM) approach; a spray module; and a joint probability density function for species and enthalpy.

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APNASA 21 Blade Row Compressor Simulation Turnaround Time Reduced by a Factor of 400:1

COMPUTER HARDWAREIMPROVEMENTS

BASELINE ANALYSIS1992

PARALLELPROCESSING

ALGORITHMICCHANGES

INCREASEDRESOLUTION

~ ÷ 40

~ 2.4 X

~ ÷ 6

Factors Influencing Turnaround TimeEstimated Turnaround TimeEstimated Turnaround Time

Ho

urs

~ ÷ 4

6

0.29

0.3

0.31

0.32

0.33

0.34

0.35

0 200 400 600 800 1000 1200 1400 1600 1800

time step

Dynamic Stress Prediction

Unsteady Aerodynamic Loading

Forced Response

Aeroelastic Analysis using TURBO

• TURBO version for fluid-structure interaction analysis being developed

– three-dimensional, viscous, unsteady aerodynamics– Purge flow, real gas effects, K-Baldwin-Lomax

turbulence models

– phase-lagged boundary conditions reduce computational domain to one blade passage per blade row

– dynamic grid deformation to simulate blade vibration

• Code validated for flutter analysis– Pratt & Whitney, Honeywell and Rolls-Royce Allison used

code on in-house data to predict flutter

• Validation in progress for forced response– GE validating the code using in-house data

Mass Flow

FlutterMode 1Mode 2

Aer

o-D

amp

ing

No FlutterFlutter

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Probability of Failure

Response (stress)

Resistance (strength)

Structural Response

Probabilistic Loads

P

Mechanical

P

Thermal

Information for Reliability

& Risk Assessment

Probability of Occurrence

Probabilistic Materials Behavior

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Geometry and Material

Multidisciplinary Probabilistic Heat Transfer/Structural analysis code

Probabilistic Simulation of Component Reliabilityusing NESTEM

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Validated Models

Fluids Heat Transfer Combustion Structures Materials Controls Manufacturing Economics

Rapid AffordableComputation of:

Performance Stability Cost Life CertificationRequirements

Integrated Interdisciplinary Analysisand Design of Propulsion Systems

High Performance Computing

Parallel Processing Object-oriented Architecture Expert Systems Interactive 3-D Graphics High Speed Networks Database Management Systems

A Numerical Test Cell for Aerospace Propulsion SystemsA Numerical Test Cell for Aerospace Propulsion Systems

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Aero-Space Propulsion Simulation and Modeling

Government•NASA

•ARC•LaRC•MSFC

•Air Force Research Laboratory•Naval Air Research Center•Arnold Engineering and Development Center•Department of Energy

Industry•General Electric•Pratt&Whitney•Honeywell•Rolls-Royce Allison•Williams Intl.•Teledyne Continental•Boeing•Lockheed-Martin

A Government/Industry/University Partnership

University•Stanford•Cleveland State•Winston-Salem•IUPUI•Mississippi State

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• Numerical Zooming and Geometry Access Standards through NPSS for physics based modeling

• NPSS Common System Model expected to save Aircraft Industry $50M/year

Simulation Environment

•Computationally efficient (cross-platform operation, parallel processing)

•Modular design (object-oriented:“Plug-n-Play” system model assembly, easily modified and expanded)

•Provide a common modeling tool for U.S. Government, aerospace industry, and academia

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The Road to Full 3D Overnight Engine Simulation

Full 3-D Primary Flow PathScheduled for Completion

2Q FY2001

High Pressure CoreScheduled for Completion

3Q FY2000

Compressor SimulationCompleted 1998

Combustion SubsystemCompleted 4Q FY1999

Turbine SubsystemCompleted FY1998

Single StageCompleted 1990

Single Blade RowCompleted 1985

CD-00-79981

Fan/BoosterScheduled for Completion3Q FY2000

NPSS for Space Transportation

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Engine-Airframe Structural Simulations Provide High Fidelity Analysis and Assessment of Blade-Out Event

NASA Glenn, General Electric Aircraft Engines, Pratt & Whitney, and Boeing have teamed to develop new simulation tools for engine-airframe structural systems. Development of these tools will enable high-fidelity

analyses of blade-out events, more credible design of engine containment systems and improvements in blade-out margin-of-safety predictions.

Mathematical Modeling of Turbomachine Rotors

Physics Based Blade Loss Modeling

Industry/Government Standard Simulation

Procedures

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ISE Vision and Long-Term Goal

VisionTo effect a cultural change that integrates into practice widely-

distributed science, technology and engineering teams to rapidly create innovative, affordable products

VisionTo effect a cultural change that integrates into practice widely-

distributed science, technology and engineering teams to rapidly create innovative, affordable products

Long-Term GoalTo develop the capability for personnel at dispersed geographic

locations to work together in a virtual environment, using computer simulations to model the complete life-cycle of a product/mission with near real-time response time before

commitments are made to produce physical products

Long-Term GoalTo develop the capability for personnel at dispersed geographic

locations to work together in a virtual environment, using computer simulations to model the complete life-cycle of a product/mission with near real-time response time before

commitments are made to produce physical products

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ISE Will Enable Tomorrow What Cannot Be Easily Done Today

•Comprehensive life-cycle trade-studies to: – reduce design cycle time and testing– reduce redesign and rework, – reduce maintenance costs– increase performance and safety

• Bound uncertainties arising from assumptions, scarcity of knowledge and unknowns

• Comprehensive and rapid mission life-cycle simulations will minimize the risks and maximize the benefits

• Provide a means for productive teaming of the best and brightest people and capabilities

• Create and assess new innovative design options and new technologies from anywhere and at anytime

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SummaryRevolutionary advances in simulation and modeling will lead to increased design confidence that translates into significant reductions in aerospace propulsion:

• Development, manufacturing and certification time and cost• Maintenance and operations costs

Greater opportunities to introduce advanced technologies that “buy their way” into new products

Government/Industry/University partnerships are required to accomplish these goals and to ensure technology transfer

Useful products must be delivered throughout the Program on a frequent basis to sustain interest

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EngineeringEngineering ApplicationsApplications

Computing TestbedsComputing Testbeds

SimulationSimulationEnvironmentEnvironment

• Code Parallelization• 3–D Subsystems/System

Gov’t/Industry Collaborative Effort Object - Oriented Programming CAD Geometry Interface

Coupled Aero-Thermal-Structural Analysis

Multi-physics Methods

0–D Engine/1–D Compressor

0–D Core/3–D LP Subsystem

High-Speed Networks PC Cluster Metacenter Computing

Seamless Integration ofData, Analysis Tools andComputing Resources

High Fidelity, Large Scale Simulations

Low-Cost, DistributedParallel Computing

Major Elements of NPSS

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APNASA Coupled Flow Simulation of High Pressure-Low Pressure Turbines Results in Significant Fuel Savings

Objective:Create a high-fidelity computer simulation of the flow through a full modern high bypass ratio turbofan engine.

Approach:Using a modular approach to the full engine simulation goal, a flow simulation of the tightly coupled high pressure and low pressure turbines has been completed. The computer simulation was performed using NASA’s 3-D average passage approach (APNASA). The simulation was done using 121 processors of a Silicon Graphics Origin cluster with a parallel efficiency of 87% in 15 hours.

Significance:The accurate and rapid simulation of a large turbine subsystem enabled designers to reduce turbine interaction losses in dual-spool engines by 50%. This will result in a $3 million/year savings in fuel costs for a typical fleet of commercial aircraft.

Point of Contact: Joseph P. Veres (216)433-2436

Low PressureTurbine

High Pressure Turbine

Transition Duct