Heat-Transfer Measurements in an Inexpensive Supersonic Wind Tunnel: 1—Apparatus and Results for a Laminar Boundary Layer Based on a Simple One-Dimensional Flow Model

1955 ◽  
Vol 22 (3) ◽  
pp. 289-296
Author(s):  
Joseph Kaye ◽  
J. H. Keenan ◽  
G. A. Brown ◽  
R. H. Shoulberg
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Reynolds Number ◽  
Laminar Boundary Layer ◽  
Flow Model ◽  
Transfer Coefficients ◽  
Supersonic Wind Tunnel ◽  
One Dimensional ◽  
Heat Transfer Coefficients ◽  
Dimensional Flow

Abstract Reliable experimental data, obtained at relatively low cost, are presented in the form of heat-transfer coefficients for air moving at supersonic speeds in a round tube. These data are analyzed, interpreted, and compared with available data in the literature. The experimental local heat-transfer coefficients are for laminar, transitional, and turbulent boundary layers. The data for a laminar boundary layer, comprising 17 runs, are discussed here for Mach numbers at tube inlet of 2.8 and 3.0. The range of values of diameter Reynolds number covered is from 20,000 to 100,000 for these laminar-flow tests, while the length Reynolds number extends to about 4,000,000. The computed quantities are obtained on the basis of a simple one-dimensional flow model, but a companion paper will analyze the same data in greater detail on the basis of a two-dimensional flow model.

Heat-Transfer Measurements in an Inexpensive Supersonic Wind Tunnel: 2—Results for a Laminar Boundary Layer Based on a Two-Dimensional Flow Model

1955 ◽  
Vol 22 (3) ◽  
pp. 297-304
Author(s):  
Joseph Kaye ◽  
G. A. Brown
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Supersonic Flow ◽  
Laminar Boundary Layer ◽  
Flow Model ◽  
Two Dimensional ◽  
Round Tube ◽  
One Dimensional ◽  
Dimensional Flow ◽  
Two Dimensional Flow

Abstract Reliable experimental data on local heat-transfer coefficients for supersonic flow of air in a round tube are reanalyzed in detail with the aid of an approximate two-dimensional flow model. The results are compared with similar results based on a one-dimensional flow model and with the theoretical predictions for supersonic flow over a flat plate and for flow in the entrance region of a tube when a laminar boundary layer is present. The two-dimensional flow model yields a better understanding of the phenomena which occur for diabatic supersonic flow of air in a round tube than that obtained with the aid of the one-dimensional flow model. The two-dimensional flow model shows that the core Mach number is nearly constant along the length of test section for a range of values of the inlet diameter Reynolds number. For a laminar boundary layer the values of the local Stanton number agree within a few per cent with the theoretical values for plate flow at the largest values of the inlet diameter Reynolds number.

Measurement of Recovery Factors and Friction Coefficients for Supersonic Flow of Air in a Tube: 1—Apparatus, Data, and Results Based on a Simple One-Dimensional Flow Model

1952 ◽  
Vol 19 (1) ◽  
pp. 77-96
Author(s):  
J. Kaye ◽  
J. H. Keenan ◽  
K. K. Klingensmith ◽  
G. M. Ketchum ◽  
T. Y. Toong
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Reynolds Number ◽  
Mach Number ◽  
Flow Model ◽  
Supersonic Stream ◽  
Round Tube ◽  
Adiabatic Wall ◽  
One Dimensional ◽  
Dimensional Flow

Abstract For the past few years a program has been under way to obtain reliable data on the rate of heat transfer to air moving at supersonic speeds. The investigation was limited to air flowing at supersonic speeds in a round tube. The program was divided into two separate parts, the first for measurement of the adiabatic wall temperatures of a supersonic stream and the second for the heat-transfer rate. The first part of this program is described here. The details of three experimental test combinations used to measure the adiabatic wall temperature and local state of a supersonic stream of air are presented. The experimental data for forty runs, in the form of measured pressure and temperature distributions, are included. The range of diameter Reynolds number covered is from 0.15 × 105 to 5 × 105. The length Reynolds number extends to 120 × 105. The Mach number at the inlet to the round tube is about 2.6. The calculated quantities such as the local apparent friction coefficient, recovery factor, local Mach number, and so forth, are obtained from the simple one-dimensional flow model for which the properties of the stream are uniform at any cross section of the tube and boundary-layer effects are ignored. A subsequent paper deals with the calculation of these quantities when account is taken of the boundary-layer growth in the tube on the basis of a two-dimensional flow model.

Darryl E. Metzger Memorial Session Paper: Comparison of Calculated and Measured Heat Transfer Coefficients for Transonic and Supersonic Boundary-Layer Flows

1995 ◽  
Vol 117 (2) ◽  
pp. 248-254 ◽  
Author(s):  
C. Hu¨rst ◽  
A. Schulz ◽  
S. Wittig
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Reynolds Number ◽  
High Speed ◽  
Three Dimensional ◽  
Supersonic Boundary Layer ◽  
Nozzle Wall ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Three Dimensional Finite Element

The present study compares measured and computed heat transfer coefficients for high-speed boundary layer nozzle flows under engine Reynolds number conditions (U∞=230 ÷ 880 m/s, Re* = 0.37 ÷ 1.07 × 106). Experimental data have been obtained by heat transfer measurements in a two-dimensional, nonsymmetric, convergent–divergent nozzle. The nozzle wall is convectively cooled using water passages. The coolant heat transfer data and nozzle surface temperatures are used as boundary conditions for a three-dimensional finite-element code, which is employed to calculate the temperature distribution inside the nozzle wall. Heat transfer coefficients along the hot gas nozzle wall are derived from the temperature gradients normal to the surface. The results are compared with numerical heat transfer predictions using the low-Reynolds-number k–ε turbulence model by Lam and Bremhorst. Influence of compressibility in the transport equations for the turbulence properties is taken into account by using the local averaged density. The results confirm that this simplification leads to good results for transonic and low supersonic flows.

The Calculation of Heat Transfer Coefficients from Skin Friction Coefficients in the Compressible Laminar Boundary Layer on an Aerofoil

1968 ◽  
Vol 19 (3) ◽  
pp. 243-253 ◽  
Author(s):  
R. E. Luxton
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Pressure Gradient ◽  
Skin Friction ◽  
Laminar Boundary Layer ◽  
Strong Dependence ◽  
Transfer Coefficients ◽  
Friction Coefficients ◽  
Heat Transfer Coefficients ◽  
Similar Solutions

SummaryIn this note a relation is established between the correlation parameters obtained by Cohen and Reshotko from similar solutions of the compressible laminar boundary layer, and the Pohlhausen-type pressure gradient parameter used in the approximate methods devised by Luxton and Young. A simple graphical procedure is presented to allow heat transfer coefficients to be obtained from known skin friction coefficients in the presence of a pressure gradient. In view of the restrictions of the similar solutions it cannot be claimeda priorithat the method gives accurate results. It does, however, reflect the strong dependence of the heat-transfer skin-friction relation on the pressure gradient and, by reference to calculated results published previously, it is suggested that the method may give adequate accuracy under quite severe conditions.

Comparison of Calculated and Measured Heat Transfer Coefficients for Transonic and Supersonic Boundary-Layer Flows

1994 ◽  
Author(s):  
C. Hürst ◽  
A. Schulz ◽  
S. Wittig
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Reynolds Number ◽  
High Speed ◽  
Three Dimensional ◽  
Supersonic Boundary Layer ◽  
Nozzle Wall ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Three Dimensional Finite Element

The present study compares measured and computed heat transfer coefficients for high speed boundary layer nozzle flows under engine Reynolds-number conditions (U∞ = 230 ÷ 880 m/s, Re* = 0.37 ÷ 1.07 · 106). Experimental data have been obtained by heat transfer measurements in a two-dimensional, non-symmetric, convergent-divergent nozzle. The nozzle wall is convectively cooled using water passages. The coolant heat transfer data and nozzle surface temperatures are used as boundary conditions for a three-dimensional finite-element code which is employed to calculate the temperature distribution inside the nozzle wall. Heat transfer coefficients along the hot gas nozzle wall are derived from the temperature gradients normal to the surface. The results are compared with numerical heat transfer predictions using the low Reynolds-number k-ε turbulence model by Lam and Bremhorst. Influence of compressibility in the transport equations for the turbulence properties is taken into account by using the local averaged density. The results confirm that this simplification leads to good results for transonic and low supersonic flows.

A note on expansions for the two-dimensional, compressible, laminar boundary layer equations near a point of zero skin friction

1983 ◽  
Vol 94 (1-2) ◽  
pp. 93-96 ◽  
Author(s):  
G. Wilks
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Skin Friction ◽  
Laminar Boundary Layer ◽  
Two Dimensional ◽  
Transfer Coefficients ◽  
Boundary Layer Equations ◽  
Heat Transfer Coefficients

SynopsisThe first non-arbitrary coefficient, α12, of the Buckmaster expansions is evaluated in the context of the extended Goldstein-Stewartson theory. Leading terms of the next order contributions to the skin friction and heat transfer coefficients are also obtained.

Influence of Mainstream Turbulence on Heat Transfer Coefficients From a Gas Turbine Blade

1994 ◽  
Vol 116 (4) ◽  
pp. 896-903 ◽  
Author(s):  
L. Zhang ◽  
J.-C. Han
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Reynolds Number ◽  
Heat Transfer Coefficient ◽  
Gas Turbine ◽  
Surface Heat ◽  
Transfer Coefficients ◽  
Suction Surface ◽  
Heat Transfer Coefficients ◽  
The Heat Transfer Coefficient

The influence of mainstream turbulence on surface heat transfer coefficients of a gas turbine blade was studied. A five-blade linear cascade in a low-speed wind tunnel facility was used in the experiments. The mainstream Reynolds numbers were 100,000, 200,000, and 300,000 based on the cascade inlet velocity and blade chord length. The grid-generated turbulence intensities at the cascade inlet were varied between 2.8 and 17 percent. A hot-wire anemometer system measured turbulence intensities, mean and time-dependent velocities at the cascade inlet, outlet, and several locations in the middle of the flow passage. A thin-foil thermocouple instrumented blade determined the surface heat transfer coefficients. The results show that the mainstream turbulence promotes earlier and broader boundary layer transition, causes higher heat transfer coefficients on the suction surface, and significantly enhances the heat transfer coefficient on the pressure surface. The onset of transition on the suction surface boundary layer moves forward with increased mainstream turbulence intensity and Reynolds number. The heat transfer coefficient augmentations and peak values on the suction and pressure surfaces are affected by the mainstream turbulence and Reynolds number.

scholarly journals Effect of Integrating Metal Wire Mesh with Spray Injection for Liquid Piston Gas Compression

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3723
Author(s):  
Barah Ahn ◽  
Vikram C. Patil ◽  
Paul I. Ro
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Enhancement ◽  
Metal Wire ◽  
Wire Mesh ◽  
Transfer Enhancement ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Gas Compression ◽  
Liquid Piston

Heat transfer enhancement techniques used in liquid piston gas compression can contribute to improving the efficiency of compressed air energy storage systems by achieving a near-isothermal compression process. This work examines the effectiveness of a simultaneous use of two proven heat transfer enhancement techniques, metal wire mesh inserts and spray injection methods, in liquid piston gas compression. By varying the dimension of the inserts and the pressure of the spray, a comparative study was performed to explore the plausibility of additional improvement. The addition of an insert can help abating the temperature rise when the insert does not take much space or when the spray flowrate is low. At higher pressure, however, the addition of spacious inserts can lead to less efficient temperature abatement. This is because inserts can distract the free-fall of droplets and hinder their speed. In order to analytically account for the compromised cooling effects of droplets, Reynolds number, Nusselt number, and heat transfer coefficients of droplets are estimated under the test conditions. Reynolds number of a free-falling droplet can be more than 1000 times that of a stationary droplet, which results in 3.95 to 4.22 times differences in heat transfer coefficients.

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