1、NASA Contractor Report 4653Effects of Cavity Dimensions, Boundary Layer,and Temperature on Cavity Noise WithEmphasis on Benchmark Data To ValidateComputational Aeroacoustic CodesK. K. Ahuja and J. MendozaGeorgia Institute of Technology Atlanta, GeorgiaNational Aeronautics and Space AdministrationLan
2、gley Research Center Hampton, Virginia 23681-0001I IIPrepared for Langley Research Centerunder Contract NAS1-19061iApril 1995Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-This publication is available from the following sources:NASA Center for Aero
3、Space Information800 Elkridge Landing RoadLinthicum Heights, MD 21090-2934(301) 621-0390National Technical Information Service (NTIS)5285 Port Royal RoadSpringfield, VA 2216!-2171(703) 487-4650Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-FOREWORD/
4、ACKNOWLEDGMENTSThis report was prepared by the Acoustics, Aerodynamics, and AdvancedVehicles Division of the Aerospace Laboratory of Georgia Tech Research Institute(GTRI), a unit of Georgia Institute of Technology, for NASA Langley Research Center,Hampton, Virginia, under Contract NAS 1-19061, Task
5、Assignment 13.Mr. Earl Booth, Jr. was the Project Manager for NASA Langley Research Center.GTRIs Project Director was Dr. K. K. Ahuja. This program was initiated by Dr. JayHardin of NASA Langley Research Center who maintained close contact with theinvestigators of this program throughout the course
6、of this program.The authors would like to acknowledge the assistance of a number of GeorgiaTech students. They include Cori Thompson who constructed the water table for cavityflow visualization and performed much of the farfield acoustic data analysis; Rob Stokerwho developed a code to aid in the pr
7、essure contour analysis and assisted in pressurecontour data acquisition; Becky McGuinn who designed the initial nozzle/cavityconfiguration and conducted initial literature survey; and Mike Dewey, Eric Dreyer, ToddElsbernd, Josh Freeman, and Jack Manes for their assistance in the farfield acoustic d
8、ataacquisition process. Particular thanks are due to Jeff Hsu for his assistance in automationof the data acquisition process and to John Wiltze for his assistance in acquiringturbulence data.111Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provide
9、d by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TABLE OF CONTENTSSection1.1.11.21.31.42.2.12.1.12.1.23.3.13.1.13.1.23.23.2.13.2.23.2.33.2.43.2.53.2.63.33.3.13.3.24.4.14.24.34.44.54.5.14.5.24.5.34.5.4Title PageINTRODUCTION . 3PROGRAM OBJECTIVE . 3TYPES OF ME
10、ASUREMENTS MADE 3SUMMARY OF TECHNICAL APPROACH 4OUTLINE OF REPORT . 5CAVITY TONES AND PERTINENT EQUATIONS . 7CAVITY TONES AND THEIR CALCULATIONS 10Feedback Resonance . 11Cavity Acoustic Resonance 12TECHNICAL APPROACH AND TEST CONDITIONS 19FLOW QUALITY VALIDATION . 20Turbulence Flow . 20Flow Uniformi
11、ty . 22TASK DESCRIPTIONS . 23Task 1 - Cavity Model Design 23Task 2 - Flow Visualization 24Task 3 - Fluctuating-Pressure-Field Measurements 24Task 4 - Flow-Velocity Measurements . 25Task 5 - Upstream Boundary-Layer Measurements . 25Task 6 - Turbulence Measurements 25TEST CONDITIONS 26Unheated Flow Pr
12、ogram Chart . 26Heated Flow Program Chart . 27THE EFFECT OF WIDTH ON CAVITY NOISE . 41INTRODUCTION 41PREVIOUS WORK ON THE EFFECT OF WIDTH 41A NOTE ON 2-D AND 3-D CAVITY FLOWS . 42TERMINOLOGY . 42TEST FACILITY AND EXPERIMENTAL PROCEDURES 43Farfield-Noise Facility 43Nozzle and Cavity Configurations 43
13、Data Acquisition and Processing 44Test Parameters . 44P-J_Ct,_II_G PAI:d_ I_.ANK NOt FILMEDVINTENTIOIiALLYBLANKProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4.64.75.5.15.25.35.3.15.3.25.45.4.15.4.25.4.35.56.6.16.26.36.46.56.66.6.16.6.26.6.36.6.46.7
14、6.87.7.17.27.3IMPORTANT OBSERVATIONS AND DISCUSSION 45CONCLUDING REMARKS 47THE EFFECT OF LENGTH-TO-DEPTH RATIO ONCAVITY NOISE IN THE FARFIELD . 63INTRODUCTION 63TERMINOLOGY . 64TEST FACILITY AND EXPERIMENTAL PROCEDURES 65Test Set-Up . 65Test Conditions 65IMPORTANT OB SERVATIONS AND DISCUSSION 67Gene
15、ral Observations on the Cavity Noise Spectra 67Shallow-Cavity Tones Versus Deep Cavity Tones . 67Directivity of Cavity Tones . 71CONCLUDING REMARKS 72EFFECTS OF TEMPERATURE ON CAVITY TONEFREQUENCIES 139INTRODUCTION 139PREVIOUS WORK ON THE EFFECTS OF REYNOLDSNUMBER 139A NOTE ON CAVITY SOUND PRESSURE
16、LEVELS INTHIS INVESTIGATION 140A NOTE ON CAVITY TONE PREDICTION AT ELEVATEDTEMPERATURES . 141TERMINOLOGY 142TEST FACILITY AND EXPERIMENTAL PROCEDURES 142Hot-Flow Facility 142Nozzle and Cavity Configuration . 143Data Acquisition and Processing 143Test Parameters . _44IMPORTANT OBSERVATIONS AND DISCUS
17、SION 144CONCLUDING REMARKS 146EFFECTS OF UPSTREAM BOUNDARY LAYERTHICKNESS ON CAVITY NOISE . 167INTRODUCTION 167A SUMMARY OF PREVIOUS WORK 168TERMINOLOGY . 168viProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-7.47.4.17.4.27.4.37.57.5.17.5.27.67.78.8.1
18、8.28.38.48.58.5.18.5.28.5.38.68.6.18.6.28.79.9.19.29.39.3.19.3.29.3.39.49.59.69.79.8TEST FACILITY 169Flow-VisualizationFacility.169Nozzle and Cavity Configuration.169TestConditions.170DATA ACQUISITIONS AND PROCESSING .170Acoustic Data 170Boundary Layer ProfileData 170IMPORTANT OBSERVATIONS AND DISCU
19、SSION 172CONCLUDING REMARKS 173CHARACTERIZATION OF THE EXCITED INSTABILITYWAVES AND TURBULENCE IN THE SHEAR LAYER OFA CAVITY 183INTRODUCTION 183A NOTE ON TAYLORS HYPOTHESIS 184TERMINOLOGY . 185TEST SET-UP . 185DATA ACQUISITION AND PROCESSING 185Convection Velocities . 185Wave Number Spectra 186Test
20、Conditions 187IMPORTANT OBSERVATIONS AND DISCUSSION 187Instability Wave Convection Velocity 187Instability-Wave Growth Rate 188CONCLUDING REMARKS 190NEARFIELD PRESSURE CONTOURS OF CAVITY NOISE 201INTRODUCTION . 201TERMINOLOGY . 201TEST FACILITY 202Farfield-Noise Facility 202Water-Table Facility . 20
21、2Cavity-Flow Simulation Nozzle and Cavity Configurations 202DATA ACQUISITION AND PROCESSING 203TEST CONDITIONS 204A WORD OF CAUTION .204IMPORTANT OBSERVATIONS AND DISCUSSION 205CONCLUDING REMARKS 210viiProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
22、10.11.OVERALL CONCLUSIONS . 247REFERENCES 249APPENDIX A: NOMENCLATURE 253APPENDIX B: COMPATIBILITY BETWEEN FACILITIES 255!oVIIIProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-LIST OF FIGURES2.12.22.32.42.53.13.23.33.43.53.63.73.83.93.103.113.12Schema
23、tic of the cavity air flow receptivity between the shear layerinstability wave and the sound wave disturbances 14Non-dimensional cavity feedback frequencies, predicted by Rossitersequation, as a function of Mach number. 15Calculated Strouhal numbers for feedback (solid lines) and depth modelresonanc
24、e as a function of Mach number for L/D = 0.5, D = 5.08 cm (2.0in) 16Calculated Strouhal numbers for feedback (solid lines) and depth modelresonance as a function of Mach number for L/D = 1.0., D = 5.08 cm (2.0in) 17Calculated Strouhal numbers for feedback (solid lines) and depth modelresonance as a
25、function of Mach number for L/D = 1.5, D = 5.08 cm (2.0in) 18Four test facilities used in the present program 28Boundary layer probe used in the Flow-Visualization Facility 29Schematic of the cavity and boundary layer probe for data acquisition ofvelocity profiles . 30Velocity profile for cavity flo
26、w a the nozzle centerline and 0.3175 _m(0.125 in) upstream of the cavityVelocity profile for cavity flow(0.125 in) upstream of the cavityVelocity profile for cavity flowleading edge for M = 0.26 . 31a the nozzle centerline and 0.3175 cmleading edge for M = 0.4 . 32a the nozzle centerline and 0.3175
27、cm(0.125 in) upstream of the cavity leading edge for M = 0.53 . 33Velocity profiles of the wall jet with the cavity closed . 34Core length comparison between different Mach numbers using a probetraversed along the nozzle centerline 35Total pressure distribution at the nozzle centerline along the fre
28、estreamdirection for L/D = 0.5, L = 2.54 cm (1.0 in), and M = 0.26 36Total pressure distribution at the nozzle centerline along the freestreamdirection or L/D = 1.0, L = 5.08 cm (2.0 in), and M = 0.26 . 37Total pressure distribution at the nozzle centerline along the freestreamdirection for L/D = 1.
29、5, L = 7.62 cm (3.0 in), and M = 0.26 38Test program chart for unheated cavity flow operating conditions(Larger unfilled circles indicate data points presented in this report) . 39ixProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3.134.14.24.34.44.54
30、.64.74.84.94.104.114.124.134.145.15.25.3Test program chart for high temperature cavity flow operation conditions.(Cavity depth is assumed to be 5.08 cm (2.0 in) . 40Flow visualization using nylon fluorescent mini-tufts for L/D = 0.5, L =2.54 cm (1.0 in), L/W = 0.25, and M = 0.16 . 49Cavity flow (wid
31、th effects) terminology . 50Farfield-Noise Facility at GTRI 51Cavity model design for rectangular nozzle . 52Cavity blocks used for effects of width study where the colored blockscorrespond to the following L/Ws; (a) bottom left - I_,/W = 0.47, (b) top left- L/W = 0.63, (c) top right - L/W = 1.88, (
32、d) bottom right - L/W = 3.75 . 53Effect of L/W on unheated cavity flow narrow band (Af = 128 Hz) noisespectra for L = 4.763 (1.875 cm), L/D = 3.75, M = 0.400, and O = 90 54Effect of L/W on unheated cavity flow narrow band (Af = 128 Hz) norsespectra for L = 4.763 (1.875 cm), L/D = 3.75, M = 0.530, an
33、d O = 90 54Effect of L/W on unheated cavity flow narrow band (Af = 128 Hz) noisespectra for L = 4.763 (1.875 cm), L/D = 3.75, M = 0.672, and O = 90 55Effect of L/W on unheated cavity flow narrow band (Af = 128 Hz) noisespectra for L = 4.763 (1.875 cm), L/D = 3.75, M = 0.260, and O = 90 56Effect of L
34、/W on unheated cavity flow narrow band (Af = 128 Hz) noisespectra for L = 4.763 (1.875 cm), L/D = 3.75, M = 0.800, and O = 90 57Effect of L/W on unheated cavity flow narrow band (Af = 128 Hz) noisespectra for L = 4.763 (I.875 cm), L/D = 3.75, M = 0.900, and O = 90 58Effect of L/W on unheated cavity
35、flow narrow band (Af = 128 Hz) noisespectra for L = 4.763 (1.875 cm), L/D = 3.75, M = 1.000, and O = 90 59Effect of L/W on directivity for a fixed L/D = 3.75, L = 4.78 cm (1.88in), M = 0.53, and f = 2800 Hz . 60Narrow band (Af = 128 Hz) noise spectra of cavity flow for M = 0.400,Re = 4.9 x 105, and
36、L/D = 1.0 61Cavity flow terminology for the investigation of the farfield acoustics . 74Test conditions for the farfield acoustic study of cavity flows . 75(Larger unfilled circles indicate data points discussed in this section.)Narrow band (Af = 128 Hz) noise spectra of cavity flow for M = 0.260,Re
37、 = 1.60 x 105, L/D = 0.5, L = 2.54 cm (1.0 in), W/D = 2.0, and L/W =0.250 76Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-5.45.55.65.75.85.95.105.115.125.135.145.15Narrowband(Af = 128Hz) noisespectraof cavity flow for M = 0.400,Re= 2.40x 105,L/D =
38、0.5, L = 2.54cm (1.0in), W/D = 2.0, andL/W =0.250.,77Narrowband(Af = 128Hz) noisespectraof cavity flow for M = 0.530,Re= 3.20x 105,L/D = 0.5, L = 2.54cm (1.0in), W/D = 2.0,andL/W =0.25078Narrow band (15_f= 128 Hz) noisespectraofcavityflow forM = 0.672,Re = 4.00 x 105,L/D = 0.5,L = 2.54cm (I.0in),W/D
39、 = 2.0,and L/W -0.25079Narrow band (_ff= 128 Hz) norsespectraofcavityflow forM = 0.260,Re = 2.40 x 105,L/D = 0.75,L = 3.81cm (1.5in),W/D = 2.0,and L/W =0.37580Narrow band (Lff= 128 Hz) no_sespectiaofcavityflow forM = 0.400,Re = 3.70 x 105,L/D = 0.75,L = 3.81cm (1.5in),W/D = 2.0,and L/W =0.375.81Narr
40、ow band (Z_d“= 128 Hz) nolsespectraofcavityflowforM = 0.530,Re = 4.80 x 105,I_/D= 0.75,L = 3.81cm (1.5in),W/D = 2.0,and I./W =0.37582Narrow band (Zkf= 128 Hz) nolsespectraofcavityflow forM = 0.672,Re = 6.00x 105,IJD = 0.75,L = 3.81cm (1.5in),W/D = 2.0,and I./W =0.37583Narrow band (Af= 128 Hz) noises
41、pectraofcavityflow forM = 0.260,Re = 3.20x 105,L/D = 1.0,L = 5.08cm (2.0in),W/D = 2.0,and L/W =0.50 84Narrow band (Af = 128 Hz) noise spectra of cavity flow for M = 0.400,Re = 4.90 x 105, L/D = 1.0, L = 5.08 cm (2.0 in), W/D = 2.0, and L/W =0.50 . . 85Narrow band (Af= 128 Hz) noise spectra of cavity
42、 flow for M = 0.530,Re = 6.40 x 105, L/D = 1.0, L = 5.08 cm (2.0 in), W/D = 2.0, and L/W =0.50 86Narrow band (Af = 128 Hz) noise spectra of cavity flow for M = 0.672,Re - 8.00 x 105, L/D = 1.0, L = 5.08 cm (2.0 in), W/D = 2.0, and L/W =0.50 _. 87Narrow band (Af = 128 Hz) noise spectra of cavity flow
43、 for M = 0.260,Re = 1.13 x 105, I_/D = 1.5, L = 1.905 cm (0.75 in) W/D = 8.0, andL/W = 0.1875 “ 88xiProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-5.165.175.185.195.205.215.225.235.245.255.265.27Narrow band (Af = 128 Hz) noise spectra of cavity flow
44、 for M = 0.400,Re = 1.73 x 105, L/D = 1.5, L = 1.905 cm (0.75 in) W/D = 8.0, andL/W = 0.1875 89Narrow band (Af = 128 Hz) noise spectra of cavity flow for M = 0.530,Re = 2.26 x 105, L/D = 1.5, L = 1.905 cm (0.75 in) W/D = 8.0, andI_,/W = 0.1875 90Narrow band (Af = 128 Hz) noise spectra of cavity flow
45、 for M = 0.672,Re = 2.82 x 105, L/D = 1.5, L = 1.905 cm (0.75 in) W/D = 8.0, andL/W = 0.1875 91Narrow band (Af = 128 Hz) noise spectra of cavity flow for M = 0.260,Re = 1.89 x 105, L/D = 2.5, L - 3.175 cm (1.25 in), W/D = 8.0,and L/W = 0.3125 . 92Narrow band (Af = 128 Hz) noise spectra of cavity flo
46、w for M = 0.400,Re = 2.88 x 105, L/D = 2.5, L = 3.175 cm (1.25 in), W/D = 8.0,and L/W = 0.3125 . 93Narrow band (Af= 128 Hz) noise spectra of cavity flow for M = 0.530,Re = 3.77 x 105, L/D = 2.5, L = 3.175 cm (1.25 in), W/D = 8.0,and L/W = 0.3125 . 94Narrow band (Af = 128 Hz) noise spectra of cavity
47、flow for M = 0.672,Re = 4.70 x 105, L/D = 2.5, L = 3.175 cm (1.25 in), W/D = 8.0,and L/W = 0.3125 . 95Narrow band (Af = 128 Hz) noise spectra of cavity flow for M = 0.260,Re = 2.83 x 105, L/D = 3.75, L = 4.775 cm (1.88 in), W/D = 8.0,and L/W = 0.47 . 96Narrow band (Af = 128 Hz) noise spectra of cavi
48、ty flow for M = 0.400,Re = 4.32 x 105, L/D = 3.75, L = 4.775 cm (1.88 in), W/D = 8.0,and I_/W = 0.47 . 97Narrow band (Af = 128 Hz) noise spectra of cavity flow for M = 0.530,Re = 5.65 x 105, L/D = 3.75, L = 4.775 cm (1.88 in), W/D = 8.0,and L/W = 0.47 . 98Narrow band (Af = 128 Hz) no_se spectra of cavity flow for M = 0.672,Re = 7.06 x 105, L/D = 3.75, L = 4.775 cm (1.88 in), W/D = 8.0,and L/W = 0.47 99Narrow band (Af = 128 Hz) noise spectra of cavity flow for M = 0.260,Re = 2.27 x 105, L/D = 6.0, L = 3.81 cm (1.5 in), W/D = 16.0,and L/W = 0.
