Thermal & Fluids Analysis Workshop TFAWS 2004 Jet Propulsion - - PowerPoint PPT Presentation

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Thermal & Fluids Analysis Workshop TFAWS 2004 Jet Propulsion - - PowerPoint PPT Presentation

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Thermal & Fluids Analysis Workshop TFAWS 2004 Jet Propulsion Laboratory Pasadena, CA. August 31, 2004 COMPARISON OF ENGINEERING LEVEL AND FULL NAVIER STOKES PREDICTIONS WITH TEST DATA AT THE NAVYS AIR BREATHING ENGINE AND AEROTHERMAL

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SLIDE 1

Thermal & Fluids Analysis Workshop TFAWS 2004

Jet Propulsion Laboratory Pasadena, CA. August 31, 2004

COMPARISON OF ENGINEERING LEVEL AND FULL NAVIER STOKES PREDICTIONS WITH TEST DATA AT THE NAVY’S AIR BREATHING ENGINE AND AEROTHERMAL TEST FACILITY T-RANGE

Ron Schultz & Dr. Warren Jaul Naval Air Warfare Center China Lake, CA

  • Dr. Gerald Russell

U.S. Army Aviation and Missile Research Development, and Engineering Center

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SLIDE 2

Overview

  • A comparison of engineering level and full Navier-Stokes predictions of

flow-field heating conditions was made for a series of aerothermal tests performed at the Naval Air Warfare Center Air Breathing Engine and Aerothermal Test Facility, T-Range, in China Lake CA.

  • Thin skin calorimeters were used to quantify the aerothermal boundary

conditions imparted to a test fixture.

  • The engineering level analysis code ATAC3D, developed under an Army

SBIR, was used to derive the local boundary conditions.

  • The full Navier-Stokes computational fluid dynamics code OVERFLOW

was used to quantify the relative flow field and resulting heat fluxes for comparison to the engineering predictions and data

  • This presentation will discuss the analytic and experimental methods

utilized to determine boundary conditions and possible flowfield effects on a complex test fixture.

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SLIDE 3

T-Range Capabilities

  • High-Pressure Air Blow Down

Facility

  • 2900 cu ft of air stored at 3000psia
  • Propane/Air combustion used to

raise enthalpy of air increased

  • Air exhausted to atmosphere at

2300 ft above sea level

  • Makeup oxygen used for engine

testing to replace that used in propane/air combustion

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SLIDE 4

T-Range Capabilities

  • Air, propane and O2 digitally

controlled by PC running LabView with full proportion-integral- differential gain control loops

  • Tt of air adjusted w/mass flow to

match hot wall heat fluxes and surface temperatures in flight

  • Free-jet nozzles: Pt in air heater

held constant so flow is perfectly expanded to avoid shocks and expansion waves

  • Direct-connect engines: Computer

control used to vary Pt and T to match variation due to missile altitude and velocity changes

Test article in nozzle free- jet Test article in nozzle free- jet

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SLIDE 5

T-Range Enhancements

  • New air heater and nozzle

being installed

– Capable of continuous

  • peration at 4500 °F

– Nozzle (13.4” exit) will

  • perate at Mach 3.65

– SUE burner uses a replaceable water-cooled liner to increase mass flow and Tt for both test cells

  • Additional air storage,

totaling 4650 cu. ft.

O P E R A T IN G E N V E L O P E

M O D E L 2 0 0 0 F L - 4 0 0 - 3 0 0 0 1 1 0 1 0 0 1 0 0 0 1 0 1 0 0 1 0 0 0 1 0 0 0 0

P r e s s u r e ( p s ia ) M a s s F lo w ( lb m /s e c )

2 0 0 0 R 3 0 0 0 R 4 0 0 0 R 5 0 0 0 R

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SLIDE 6

T-Range Enhancements

  • Stagnation heating rates

up to 1000 btu/ft2-sec (ref: 2-inch diameter hemisphere)

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SLIDE 7

T-Range Flow Conditions

  • Facility Conditions for Current Test

– Mach 1.9 Semi-Contoured Nozzle, PCHAMBER=90 psi (mass flow, mDOT, and TCHAMBER were variable to match transient environment of interest) – Facility channel labeled TPL-1 was used as a measure of chamber

  • temperature. The value of TPL-1 was used as the total temperature in

both ATAC3D and OVERFLOW

9” Nozzle Exit 4” Nozzle Throat 18”

Mach 1.9 Nozzle Contour

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SLIDE 8

Wedge Test Fixture

1.83” 2.29” 3.53” 5.0” 4.89” 1.34” 1.5” 0.03” Radius LE 3.35° Half Angle 15° Half Angle 12° Half Angle

Flat Plate Test Section Wedge Test Section Nozzle Exit

9”

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SLIDE 9

Thin Skin Calorimeter Design

3.5” 4.5” 5.0” 5.0”

A A Section A-A

0.187”

Thin Skin Wall Thickness 0.125” for Wedge Calorimeter Includes 2 Pressure Ports 9 Welded Backside Thermocouples 0.069” for Flat Calorimeter No Pressure Ports 9 Welded Backside Thermocouples

0.625” 2.500” 4.375” 3.700” 1.375” Pressure Port 1.750” 1,11 2,12 3,13 4,14 5,15 6,16 7,17 8,18 9,19

Flow

Thermocouples #s correspond to Wedge,Flat

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SLIDE 10

3-D Finite Element Analysis

FEA provided comparison of 1-D versus 3-D thermal response of calorimeter Detailed FEA provided confidence in calorimeter thermostructural response

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SLIDE 11

ATAC3D Analysis Configurations

  • 0.03” Radius LE
  • 3.35° Fin Leading Edge Half Angle
  • 15° 2nd Wedge
  • 12° Test Section Wedge
  • 0.03” Radius LE
  • 3.35° Fin Leading Edge Half Angle
  • 15° 2nd Wedge
  • Flat Test Section Wedge

Plane of Symmetry Plane of Symmetry

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SLIDE 12

Comparison of Thin Skin Data and Predictions Profile 3 Wedge

Data Compared With Predictions for Profile 3 Wedge Thin Skin Tests Using TPL-1 Chamber Condition 0.125" & 0.069" Thin Skin 100 200 300 400 500 600 700 800 900 1000 1100 5 10 15 20 25 30 35 40 Time (sec) Temperature (F) Data Profile 3 Wedge 0.125" Data Profile 3 Wedge 0.069" ATAC3D 069 TC6 ATAC3D 125 TC6

Acceptable agreement between analysis and measured test data for wedge configuration

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SLIDE 13

Comparison of Thin Skin Data and Predictions Profile 4 Wedge

Data Compared With Predictions for Profile 4 Wedge Thin Skin Tests Using TPL-1 Chamber Condition 0.125" & 0.069" Thin Skin 100 200 300 400 500 600 700 800 5 10 15 20 25 30 Time (sec) Temperature (F) Data Profile 4 Wedge 0.125" Data Profile 4 Wedge 0.069" ATAC3D Wedge 0.069" ATAC3D Wedge 0.125"

Acceptable agreement between analysis and measured test data for wedge configuration

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SLIDE 14

Profile 1 Predictions and Data Flat Test Section

TC15 Baseline Analysis Prediction TC16 Data TC15 Modified h/cp Prediction

100 200 300 400 500 600 700 800 900 1000 5 10 15 20 25 30 35 40 Time (sec) Temperature (F) Data Thin Skin TC16 CMA 55% of h/cp Baseline Prediction

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SLIDE 15

Profile 2 Predictions and Data Flat Test Section

TC11,15 Baseline TC15 55% Modified h/cp TC15 100 200 300 400 500 600 700 800 900 1000 5 10 15 20 25 30 35 40 45

Time (sec) Temperature (F)

Data Profile 2 TC15 ATAC3D Baseline DATA Thin Skin TC11 CMA 55% h/cp

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SLIDE 16

Predictions and Data Comparison

  • Why does ATAC3D provide good agreement for the

12 degree wedge calorimeter data but over predicts the thermal response for the flat configuration?

– Laminar versus Turbulent flow? – Flow separation? – Prandlt-Meyer expansion fan causing below ambient pressure distribution? – Need to assess engineering method for predicting heating

  • CFD was utilized to visualize the flowfield over the 2

configurations and provide a more rigorous characterization of the aerothermal environment

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SLIDE 17

CFD Modeling Assumptions

  • OVERFLOW full Navier-Stokes code
  • 3-dimensional flow
  • Real gas effects
  • Nozzle contour modeled
  • Boundary layer resolved for various

chamber and wall temperatures of interest: (1200°F-300°F,600°F:1800°F-300°F, 800°F)

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SLIDE 18

Velocity Contours

Non-dimensionalized by the free-stream speed of sound (337.9 m/s, 1108.6 ft/s)

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SLIDE 19

Mach Number Profile

T0=1200F, Twall = 300F Boundary Layer well resolved at the wall for both velocity and temperature. No Flow Separation & Verified Uniform Flow

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SLIDE 20

Static Pressure (P amb. = 1.0)

Low pressure on the bottom, flat, surface

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SLIDE 21

Static Temperature (T amb. = 511R).

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SLIDE 22

CFD Static Pressure on Flat Test Fixture

0.5<Ps (atm)<2.5 0.5<Ps (atm)<1.0

Sub-ambient and variable pressure at calorimeter station

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SLIDE 23

CFD Surface Static Pressure (psia)

FLAT WEDGE

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SLIDE 24

CFD Surface Recovery Temperature

FLAT WEDGE

Note: Trec is computed by extrapolating from two isothermal wall solutions (300F and 600F) to the adiabatic wall temperature.

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SLIDE 25

CFD Convective Heat Flux at Twall = 300°F

FLAT WEDGE

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SLIDE 26

CFD Shear Stress

FLAT WEDGE

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SLIDE 27

ATAC3D Shear Stress

1200 F Total Temperature Wall Shear at 300 F Wall

10 12 14 16 18 20 22 24 26 28 30 2 4 6 8 10 12 14 16 Axial Station (in) Wall Shear (psf)

Wedge ATAC3D Flat ATAC3D

CFD Wedge : 17 psf CFD Flat: 13 psf

Cal Plate Center for Wedge Cal Plate Center for Flat

Plane of Symmetry

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SLIDE 28

ATAC3D Edge Pressure

1800 F Total Temperature Edge Pressure

6 8 10 12 14 16 18 20 2 4 6 8 10 12 14 16 Axial Station (in) E d g e P ressu re (psi) Wedge ATAC3D Flat ATAC3D

CFD Wedge : 17 psi CFD Flat: 9 psi

Cal Plate Center for Wedge Cal Plate Center for Flat

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SLIDE 29

Heat Flux Comparison of ATAC3D and CFD

1200 F Total Temperature Heat Flux 300 F Wall

10 20 30 40 50 60 70 80 2 4 6 8 10 12 14 16

Axial Station (in) C old W all H eat Flux (B tu/ft2-sec)

Flat CFD Wedge CFD Wedge ATAC3D Flat ATAC3D

Cal Plate Center for Wedge Cal Plate Center for Flat

Plane of Symmetry Plane of Symmetry

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SLIDE 30

Heat Flux Comparison of ATAC3D and CFD

1200 F Total Temperature Wall Heat Flux 600 Wall

5 10 15 20 25 30 35 40 45 50 2 4 6 8 10 12 14 16

Axial Station (in) Heat Flux (Btu/ft2-sec)

Flat CFD Wedge CFD Wedge ATAC3D Flat ATAC3D

Cal Plate Center for Wedge Cal Plate Center for Flat

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SLIDE 31

Heat Flux Comparison of ATAC3D and CFD

1800 F Total Temperature Wall Heat Flux 300 F Wall

20 40 60 80 100 120 2 4 6 8 10 12 14 16

Axial Station (in) H eat Flux (B tu/ft2-sec) Flat CFD Wedge CFD Wedge ATAC3D Flat ATAC3D

Cal Plate Center for Wedge Cal Plate Center for Flat

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SLIDE 32

Heat Flux Comparison of ATAC3D and CFD

1800 F Total Temperature Heat Flux 800 F Wall

10 20 30 40 50 60 70 80 2 4 6 8 10 12 14 16

Axial Station (in) Heat Flux (B tu/ft2-sec) Flat CFD Wedge CFD Wedge ATAC3D Flat ATAC3D

Cal Plate Center for Wedge Cal Plate Center for Flat

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SLIDE 33

Assessment of ATAC3D Cone/Cylinder Heat Flux

Conical Model 3.35°/15°/12° Cones 3.35°/15°/0° Cones/Cylinder

10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Axial Station (in) Cold Wall Heat Flux (Btu/ft2-sec)

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0

Radial Station (in)

1200 F Case 15 to 12 degree 1200 F Case 3-15-0 geometry 15-12 geometry 15-0

ATAC3D axisymmetric model predicts similar heat flux reduction as measured in wedge tests and CFD predictions Angle Change : 15°/12°-20% drop : 15°/0°- 50% drop

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SLIDE 34

Summary

  • An aerothermal test series was conducted and calorimetry was

utilized to verify boundary conditions delivered by the NAWC T-Range Facility to a wedge test fixture

  • This effort is representative of the process which should be

used for all aerothermal test and evaluation efforts

– Quantify flight boundary conditions – Select appropriate aerothermal test facility/facilities – Design and analyze appropriate test fixture to ensure predictable environments are imparted to test specimens – Design and test calorimeters in position of interest – Verify predicted conditions with measured calorimeter data – Utilize CFD if flow fields are complex or uncertainties exist in aerothermal boundary conditions

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SLIDE 35

Summary Continued

  • Calorimeters

– Thin skin calorimeters provided accurate thermal response data for quantifying convective boundary conditions – Pressure gages provided verification of uniform flow for wedge configuration (were not integrated into flat test fixture)

  • Boundary Condition Predictions

– Wedge: ATAC3D provided reasonable agreement for 12 degree wedge configuration where angle change between the two wedges was small (15 degree to 12 degree) – Flat Plate: ATAC3D predictions over predicted the calorimeter data by approximately 45% – Overflow Code (CFD) provided detail predictions of flowfield variation

  • ver test fixture in agreement with measured data and verified reduced

ATAC3D boundary condition prediction were necessary – ATAC3D axisymmetric model for a cone/cylinder provided more realistic heat flux drops for the given angle changes suggesting confidence in the ATAC3D predictions for missile shapes – The ATAC3D 3-dimensional wedge model predictive techniques needs to be investigated and modified

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SLIDE 36

Future Efforts

  • Verify/modify ATAC3D analytic method for predicting

aerothermal environments on wedges

  • Modify ATAC3D to support stagnation lines on cylinders

in cross-flow

  • Continue simplification of geometry builder for ATAC3D
  • Couple ATAC3D with CFD solutions for corrected edge

conditions in complex flow regimes

  • Continue development of material database interface for

ATAC3D

  • Provide guidance to T-Range customers on test fixture

requirements to ensure acceptable and predictable flow fields and aerothermal environments