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Guggenheim Aeronautical Laboratory~://; California R.ES~.LttCH REPCRT GUGGENHEIM AERONAUTICAL LABORATORY ~://; CALIFORNIA INSTITUTE OF TECHNOLOGY HYPERSC»JIC RESEARCH PROJECT Memorandum No. 47 December 15, 1958 AN EXPERIMENTAL INVESTIGATION OF THE EFFECT OF EJECTING A COOLANT GAS AT THE NOSE OF A BLUNT BODY by C. Hugh E. Warren ARMY ORDNANCE CONTRACT NO. DA-04-495-0rd-19 GUGGENHEIM AERONAUTICAL LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY Pasadena1 California HYPERSONIC RESEARCH PROJECT Memorandum No. 4 7 December 151 1958 AN EXPERIMENTAL INVESTIGATION OF THE EFFECT OF EJECTING A COOLANT GAS AT THE NOSE OF A BLUNT BODY by C. Hugh E. Warren ~~C!a r~:Ml ia:nl bil'eCtOr Guggenheim Aeronautical Laboratory ARMY ORDNANCE CONTRACT NO. DA-04-495-0rd-19 Army Project No. 5B0306004 Ordnance Project No. TB3-0118 OOR Project No. 1600-PE ACKNOWLEDGMENTS The author wishes to express his appreciation to Professor Lester Lees for his assistance1 guidance and encouragement during this work1 to Mr. Howard McDonald and other members of the Aeronautics Machine Shop for fabricating and maintaining the models and other items of equipment1 to Mr. Paul Baloga and the staff of the Hypersonic Wind Tunnel for their assistance and advice during testing~ to Mrs. Betty Laue for much computational work1 and to Mrs. Gerry Van Gieson for typing the manuscript and piloting the report through after the author 1 s departure. Most of the work was done while the author was in receipt of a Harkness Fellowship of the Commonwealth Fund of New York1 to whom thanks are due for the opportunity to spend a year on such an instructive and interesting program in such congenial surroundings. ii ABSTRACT An experimental investigation has been made of the effe ct of ejecting nitrogen and helium coolant gases at the nose of a blunt body in the GALCIT 5 inch x 5 inch hype r sonic wind tunnel at a nominal Mach number of 5. 8. The gases wer e ejected with "swirl", to encourage them to flow tangentially to the model surface at ejection, and also st-raight out. Measurements were made of pre ssure, temperature and heat flux on the surface of the model at incidences of 0, 4, 8 degrees, and for a range of coolant gas flows. It was found that ejection with swirl did not in fact lead to an easement of the heating problem, because the high tangential velocity with which the ·coolant was injected into the boundary layer so increased the wall shear stress, and hence by the Reynolds analogy, the heat flux, that it predominated over the reduced driving temperature difference associated with the cooled boundary layer. With straight-out ejection it was found that the heat alleviation capabilities of the ejected coolant were reduced considerably if the momentum flow was sufficiently high that the bow shock wave was bulged out. For the size of ejection orifice in the present study it was possible to eject only nitrogen coolant without disturbing the external flow appreciably. The results suggest, however, that straight-out ejection could provide an effective way of reducing the heat flux provided that the external flow is not disturbed, and tests with a larger ejection orifice are indicated. A technique is proposed for making steady-state heat-flux measurements by measuring t h e temperature difference across a uniformly thin skin of uniform, low thermal conductivity. iii TABLE OF CONTENTS PART PAGE Acknowledgments ii Abstract iii Table of Contents iv List of Tables vi List of Figures ix List of Symbols xii 1. Introduction 1 2. Description of the Models 3 3. Experimental Equipment 8 3. 1. Description of Wind Tunnel and Mounting of the Model 8 3. 2. Metering of the Coolant Gas 9 3. 3. Measurement of Pressure 10 3. 4. Measurement of Temperature 10 3. 5. Measurement of Heat Flux and Calibration of Heatmeter s 11 4. Reduction of Data 15 5. Results 16 6. Discussion 17 6. 1. Pressure Distributions with No Ejection 17 6. 2. Temperature and Heat-Flux Distributions with No Ejection 18 6. 3. Effect of Ejection on the Flow Pattern 23 6. 4. Effect of Ejection on Pressure 26 iv 6. 5. Effect of Eje ction with Swirl on Temperature and Heat Flux 27 6. 6. Effect of Straight-Out Ejection on Temperature and Heat Flux 29 6. 7 0 Effect of Straight-Out Ejection on an Uncooled Model 34 7. Conclusions 36 References 39 Appendix 1 Construction of Oven 40 Appendix 2 Heat Flow in the Skin 42 Tables 44 Figures 85 v LIST OF T ABLES NUMBER PAGE 1 Model Ordinat e s, and Location of Pressure Orifice s, The r moc oupl es and Heatmeters 44 2 Pertinent Data on Tun ne l and Model 45 3 Gas Properties 46 4 Silver-Consta ntan T hermocouple Calibration (from Ref eren c e 2, F igure 5) R eference Junction 70°F 47 5 Plenum Chamber Pre ssure and Tem perature Pressure Model 48 6 Plenum Cham.ber Pre s s ure and Tempe rature Heat-Flux Model, Swirler at 45° 49 7 Plenum Chambe r Pre ssure and Tempe rature Heat-Flux Model, Swirler at 90° 50 8 Plenum C ha mber Pre s s ure and Tem p e rature Heat-Flux Model, Swirler R emoved 51 Pressure, No Eje cti on, C . 0 52 9 m = 10 Pressure, Nitrogen Ejected with Swirl, C . 0. 002 53 m = 11 Pressure, Nitrogen Ejected with Swirl, C m. = 0. 004 54 12 Pressure, Nitrogen Ejected with Swirl, C • 0. 006 55 m = 13 Pressure, Nitrogen Ejected with Swirl, C . = 0. 008 56 n1 14 Pressure, Helium Eje cted with Swirl, Zero Incidence 57 15 Temperature and Heat ·Flux, No Eje ct ion, = 0 58 c m. 16 Temperature and H eat Flux, Nitrog en Ejected with Swirler at 45°, C . 0. 0021 59 m = 17 Temperature a n d Hea t Flux, Nitrogen Eje cted with Swirler at 4 5° , C . 0. 004 2 60 m = 18 Temperature and Heat F-lux, Nitrogen Eje cte d with Swirle r at 45°, C • = 0. 0063 61 n J. Vl 19 Temperature and Heat Flux, Nitrogen Ejected with Swirler at 45°, C • = 0. 0084 62 m 20 Temperature and H eat Flux , H elium Ejected with Swirler at 45°, C . 0. 0021 63 m = 21 Tempe rature a nd H eat Flux, Heliwn Ejected with Swirler at 45°, C . = 0. 0032 64 m 22 Temperature a nd Heat Flux, Heliwn Ejected with Swirler at 45°, C • = 0. 0042 65 m 23 Temperature and H eat Flux, Heliwn Ejected with Swirler at 45°, C . = 0. 0049 66 m 24 Temperature and Heat Flux, Nitrogen Ejected with Swirler at 90°, C . 0. 002 m = 67 25 Temperature and Heat Flux, Nitrogen Ejected with Swirler at 90°, C . = 0. 001 68 m 26 Temperature and Heat Flux, Nitrogen Ejected with Swirler at 90°, C • 0. 006 69 m = .27 Temperature and Heat Flux, Nitrogen Ejected with Swirler at 90°, C • 0. 008 70 m = 28 Temperature and Heat Flux, Heliwn Ejected with Swirler at 90°, C . = 0. 002 71 m 29 Temperature and Heat Flux, Heliwn Ejected with Swirler at 90°, C . 0. 003 72 m = 30 Temperature and Heat Flux, Heliwn Ejected with Swirler at 90°, C . 0. 004 73 m = 31 Temperature and H eat Flux, Heliwn Ejected with Swirler at 90°, C . 0. 005 74 m = 32 Temperature and Heat Flux, Nitrogen Ejected Straight Out, C . 0. 002 75 m = 33 Temperature and H eat Flux, Nitrogen Ejected Straight Out, C . 0. 004 76 m = 34 Temperature and Heat Flux, Nitrogen Ejected Straight Out, C . 0. 006 77 m = vii 35 Temperature and Heat Flux, Nitrog en Ejected Straight Out, = 0. 008 78 c.m 36 Temperature and Heat Flux, H elium Ejected Straight Out, C.=O. OOl m 79 37 Temperature and Heat Flux, Helium Ejected Straight Out, = 002 80 c m. o. 38 Temperature and Heat Flux, Helium Ejected Straight Out, = 0. 004 81 c m. 39 Temperature and Heat Flux, Heli\lrn Ejected Straight Out, = 005 82 c m. o. 40 Temperature and Heat Flux with No Coolant Water Flow, Nitrog en Ejected Straight Out, Zero Incidence 83 41 Temperature and Heat FlW<: with No Coolant Water Flow, Helium Ejected Straight Out, Zero Incidence 84 viii LIST OF FIGURES NUMBER PAGE la Photograph of the Model Pressure Model 85 lb Photograph of the Model Heat-Flux Model 85 2 Construction of Models 86 3 Geometry of Models 87 4 Diagram of Calibration Oven 88 5 Distributions of Pressure, Temperature and Heat Flux in the Plane of Incidence with No Ejection (C • 0) 89 m = 6 Effect of Incidence on Pressure in the Plane of Incidence with No Ejection (C • 0) 90 m = 7 Distributions of Pressure, Temperature and Heat Flux in the Meridian Plane Normal to the Plane of Incidence with No Ejection (C • = 0) 91 m 8 Comparison.of Measurements of Heat Flux with TheorJ., No Ejection (Crh = 0), Zero Incidence (a. = 0 ) 92 9 Effect of Ejection on Plenum Chamber Pressure 93 lOa Schlieren Photograph -- Nitrogen Ejected Straight Out, C m. = 0. 004; a. = 0° 94 lOb Schlieren Photograph -- Nitrogen Ejected with Swirl, C • 0. 006; a 0° 94 m = = lOc Schlieren Photograph Helium Ejected Straight Out, C . 0. 002; a. 0° 95 m = = lOd Schlieren Photograph -- Helium Ejected with Swirl, C • = 0. 002; a. = 0° m 95 lOe Schlieren Photograph -- Nitrogen Ejected Straight Out, C • 0. 004; a 8° m = = 96 lOf Schl~eren Photograph -- Nitro5en Ejected Stratght Out, C . 0. 006; a. 8 m = = 96 lOg S~hlier~n Photograph -- Hel&um Ejected Wlth Swtrl, C .
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