scholarly journals Discussion: “Measurement of Recovery Factors and Friction Coefficients for Supersonic Flow of Air in a Tube: Part 1—Apparatus Data and Results Based on a Simple One-Dimensional Flow Model” (Kaye, J., Keenan, J. H., Klingensmith, K. K., Ketchum, G. M., and Toong, T. Y., 1952, ASME J. Appl. Mech., 19, pp. 77–96)

1953 ◽  
Vol 20 (1) ◽  
pp. 149
Author(s):  
Richard Scherrer
Keyword(s):  
Supersonic Flow ◽  
Flow Model ◽  
Friction Coefficients ◽  
One Dimensional ◽  
Dimensional Flow

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.

An Evaluation of the Average Flow Model [1] for Surface Roughness Effects in Lubrication

1980 ◽  
Vol 102 (3) ◽  
pp. 360-366 ◽  
Author(s):  
J. L. Teale ◽  
A. O. Lebeck
Keyword(s):  
Surface Roughness ◽  
Flow Model ◽  
Two Dimensional ◽  
Roughness Effects ◽  
Important Conclusion ◽  
Average Flow ◽  
One Dimensional ◽  
Dimensional Flow ◽  
Two Dimensional Flow ◽  
Average Flow Model

The average flow model presented by Patir and Cheng [1] is evaluated. First, it is shown that the choice of grid used in the average flow model influences the results. The results presented are different from those given by Patir and Cheng. Second, it is shown that the introduction of two-dimensional flow greatly reduces the effect of roughness on flow. Results based on one-dimensional flow cannot be relied upon for two-dimensional problems. Finally, some average flow factors are given for truncated rough surfaces. These can be applied to partially worn surfaces. The most important conclusion reached is that an even closer examination of the average flow concept is needed before the results can be applied with confidence to lubrication problems.

Numerical Simulation of Supersonic Combustion in Quasi One-Dimensional Flow

1991 ◽  
Author(s):  
T. Gary Yip
Keyword(s):  
Flow Model ◽  
Cone Angle ◽  
Initial Pressure ◽  
Supersonic Combustion ◽  
Propulsion Systems ◽  
One Dimensional ◽  
Hypersonic Propulsion ◽  
Dimensional Flow ◽  
Conical Shock ◽  
Shock System

Abstract Supersonic combustion induced by a two-shock system has been studied using a chemical nonequilibrium, quasi one-dimensional flow model. The combustion of stoichiometric, premixed H2-air is described by a chemistry model which consists of 11 species and 28 reactions. The freestream Mach numbers used in this calculations are 8, 10 and 12. The initial pressure is 0.01 atm and temperature 300 K. The first of the two shocks is a conical shock and the second is its reflection. Supersonic combustion has been predicted to occur at combustor pressures between 0.8 and 2.9 atmospheres, and temperatures between 1500 and 3000 K. The Mach number of the flow in the combustor is between 1.7 and 4. These combustor conditions are typical of the future hypersonic propulsion systems. The results also show the changes in the composition of the flow during the induction and heat release phases. The two-shock system is assumed to be generated by a cone. For Mach 8, 10 and 12, the minimum cone angle for generating a strong enough two-shock system to induce supersonic combustion has also been identified.

Measurement of Recovery Factors and Friction Coefficients for Supersonic Flow of Air in a Tube: 2—Results Based on a Two-Dimensional Flow Model for Entrance Region

1952 ◽  
Vol 19 (2) ◽  
pp. 185-194
Author(s):  
J. Kaye ◽  
T. Y. Toong ◽  
R. H. Shoulberg
Keyword(s):  
Boundary Layer ◽  
Supersonic Flow ◽  
Laminar Boundary Layer ◽  
Flow Model ◽  
Variable Mass ◽  
Entrance Region ◽  
Two Dimensional ◽  
Dimensional Flow ◽  
Change Of State ◽  
Two Dimensional Flow

Abstract The first part of a program to obtain reliable data on the rate of heat transfer to air moving at supersonic speeds in a tube has been devoted to measurements made on adiabatic supersonic flow of air in a tube. The details of these measurements have been described in a previous paper. The calculated quantities such as the local apparent friction coefficient, recovery factor, Mach number, and so forth, were obtained from the simple one-dimensional flow model for which the properties of the stream are uniform at any section, and boundary-layer effects are ignored. The analysis of some of the same data given in the previous paper is undertaken here with the aid of a simplified two-dimensional flow model. The supersonic flow in the tube is divided into a supersonic core of variable mass with the fluid remaining in the core undergoing a reversible adiabatic change of state, and a laminar boundary layer of variable mass. The compressible laminar boundary layer increases in thickness in the direction of flow, and then undergoes a transition to a turbulent boundary layer. The two-dimensional flow model is limited here to the region where a laminar boundary layer appears to be present in the entrance region of the tube. The results of the analysis based on the two-dimensional flow model indicate that where the flow in the tube boundary layer appears to be laminar, the measured pressures and temperatures in the tube for adiabatic supersonic flow of air could have been predicted, with sufficient accuracy for engineering problems, from measured data for supersonic flow of air over a flat plate with a laminar boundary layer, and with zero pressure gradient.

scholarly journals Predicted response of the calving glacier Svartisheibreen, Norway, and outbursts from it, to future changes in climate and lake level

1997 ◽  
Vol 24 ◽  
pp. 16-20 ◽  
Author(s):  
Michael Kennett ◽  
Tron Laumann ◽  
Bjarne Kjøllmoen
Keyword(s):  
Mass Balance ◽  
Lake Level ◽  
Flow Model ◽  
Peak Discharge ◽  
Northern Norway ◽  
One Dimensional ◽  
Dimensional Flow ◽  
Glacier Front

The Svartisheibreen glacier in northern Norway has been investigated since 1988 in connection with a proposed hydropower scheme. The scheme includes regulation of the lake into which the glacier calves. A one-dimensional flow model has been used to estimate the response of the glacier to changes in mass balance and lake level. The model predicts that a net balance, excluding calving, of 0 m a−1 will cause the glacier to retreat approximately 400 m over 50 years if lake level is maintained at 774 m a.s.l., but that the glacier front will not move significantly if lake level is lowered to 720 m a.s.l. In 1989 and 1991, lake outbursts occurred beneath the glacier. The 1991 outburst was monitored, and culminated in a peak discharge of only 3.5 m3 s−1, much less than for other reported outbursts. This outburst can be explained in a model in which the outburst tunnel passes over a subglacial threshold approximately 70 m behind the 1991 calving front. The model shows that outbursts will probably increase dramatically in size if the front retreats beyond this threshold.

scholarly journals The Effect of the Flow Distribution on the Thermal Efficiency of a Solar Collector

1986 ◽  
Vol 39 (6) ◽  
pp. 945 ◽  
Author(s):  
MJ O'Keefe ◽  
JLA Francey
Keyword(s):  
Flat Plate ◽  
Thermal Efficiency ◽  
Solar Collector ◽  
Flow Model ◽  
Flow Distribution ◽  
Isothermal Flow ◽  
One Dimensional ◽  
Dimensional Flow ◽  
Uniform Flow Distribution ◽  
Flat Plate Solar Collector

An isothermal one-dimensional flow model is used to calculate the flow distribution across the manifold of a flat plate solar collector in order to quantify the effect of a non-uniform flow distribution on the thermal efficiency for a variety of manifold geometries. The predictions of this flow model are found to compare favourably with measured isothermal flow distributions.

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