Calculation of Diffuser Efficiency for Two-Dimensional Flow

1947 ◽  
Vol 14 (3) ◽  
pp. A213-A216
Author(s):  
R. C. Binder
Keyword(s):  
Boundary Layer ◽  
Incompressible Flow ◽  
Potential Flow ◽  
Layer Growth ◽  
Two Dimensional ◽  
Dimensional Flow ◽  
Check Calculation ◽  
Two Dimensional Flow ◽  
Boundary Layer Growth ◽  
Potential Velocity

Abstract A method is presented for calculating the efficiency of a diffuser for two-dimensional, steady, incompressible flow without separation. The method involves a combination of organized boundary-layer data and frictionless potential-flow relations. The potential velocity and pressure are found after the boundary-layer growth is determined by a trial-and-check calculation.

On the Two-Dimensional Theory of Incompressible Flow Over Inlets

1986 ◽  
Vol 53 (4) ◽  
pp. 947-951
Author(s):  
A. Sanz
Keyword(s):  
Incompressible Flow ◽  
Potential Flow ◽  
Two Dimensional ◽  
Dimensional Theory ◽  
Dimensional Flow ◽  
Two Dimensional Flow

The linearized solution for the two-dimensional flow over an inlet of general form has been derived, assuming incompressible potential flow. With this theory suction forces at sharp inlet lips can be estimated and ideal inlets can be designed.

Two-Dimensional Flow Through a Diffuser With an Exit Length

1953 ◽  
Vol 20 (3) ◽  
pp. 390-392
Author(s):  
K. R. Galle ◽  
R. C. Binder
Keyword(s):  
Cross Section ◽  
Static Pressure ◽  
Pressure Rise ◽  
Layer Growth ◽  
Two Dimensional ◽  
Dimensional Flow ◽  
Two Dimensional Flow ◽  
Uniform Cross Section ◽  
Flow Through ◽  
Boundary Layer Growth

Abstract A diffuser with an “exit length” is one with a channel of uniform cross section following the diffuser. Tests were made of different diffusers with and without exit lengths. The data were for steady, incompressible, two-dimensional flow. The performance of each diffuser was improved by the presence of an exit length. As compared to flow without an exit length, flow with an exit length is characterized by a reduced boundary-layer growth, by a small decrease in the pressure rise across the diverging section, and by a decrease in the static-pressure gradient at the diffuser inlet.

Two-Dimensional Flow With Standing Vortexes in Ducts and Diffusers

1960 ◽  
Vol 82 (4) ◽  
pp. 921-927 ◽  
Author(s):  
Friedrich O. Ringleb
Keyword(s):  
Wind Tunnel ◽  
Potential Flow ◽  
Separation Control ◽  
Two Dimensional ◽  
Dimensional Flow ◽  
Princeton University ◽  
Two Dimensional Flow ◽  
Flow Through ◽  
Trapping Devices

The conditions for the equilibrium of two vortexes in a two-dimensional flow through a duct or diffuser are derived. Potential-flow considerations and a few basic results from viscous-flow theory are used for the discussion of the role of cusps as separation control and trapping devices for standing vortexes. The investigations are applied to cusp diffusers especially with regard to the wind tunnel of the James Forrestal Research Center of Princeton University.

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.

Some Measurements of Boundary-Layer Growth in a Two-Dimensional Diffuser

1959 ◽  
Vol 81 (3) ◽  
pp. 285-294 ◽  
Author(s):  
J. F. Norbury
Keyword(s):  
Boundary Layer ◽  
Static Pressure ◽  
Momentum Equation ◽  
Layer Growth ◽  
Area Ratio ◽  
Momentum Thickness ◽  
Two Dimensional ◽  
Static Pressure Distribution ◽  
Boundary Layer Growth ◽  
Flow Experiments

Low-speed experiments were carried out in a two-dimensional diffuser having a square throat and an area ratio of two to one. Measurements were made of static pressure distribution, velocity contours at throat and outlet, and boundary-layer growth along the four wall center lines. Visual flow experiments were performed using tufts and smoke filaments. Similar experiments were carried out with the throat boundary layers artificially thickened by means of round rods placed on the walls upstream. Disparities between the measured growth of momentum thickness and that predicted by the simple momentum equation are discussed, as well as the effect of the artificial thickening on diffuser efficiency.

Elastico-viscous boundary-layer flows I. Two-dimensional flow near a stagnation point

1964 ◽  
Vol 60 (3) ◽  
pp. 667-674 ◽  
Author(s):  
D. W. Beard ◽  
K. Walters
Keyword(s):  
Boundary Layer ◽  
Stagnation Point ◽  
Solid Boundary ◽  
Two Dimensional ◽  
Boundary Layer Flows ◽  
Viscous Boundary Layer ◽  
Boundary Layer Equations ◽  
Dimensional Flow ◽  
Two Dimensional Flow ◽  
Viscous Boundary

AbstractThe Prandtl boundary-layer theory is extended for an idealized elastico-viscous liquid. The boundary-layer equations are solved numerically for the case of two-dimensional flow near a stagnation point. It is shown that the main effect of elasticity is to increase the velocity in the boundary layer and also to increase the stress on the solid boundary.

scholarly journals Chemical Reaction Influence on General Fluid

2019 ◽  
Vol 9 (2) ◽  
pp. 808-813
Keyword(s):  
Boundary Layer ◽  
Chemical Reaction ◽  
Radiation Effects ◽  
Two Dimensional ◽  
Permeable Plate ◽  
Electrically Conducting ◽  
Dimensional Flow ◽  
Perturbation Procedure ◽  
Two Dimensional Flow ◽  
Fluid Parameters

This paper focuses on unsteady, two-dimensional, flow boundary layer of a incompressible viscous electrically conducting and absorbing heat fluid along a semi-infinite vertical moving permeable plate in the presence of Chemical reaction and radiation effects. The dimensionless equations are analytically solved using perturbation procedure. The effects of the different flow fluid parameters on velocity, temperature and concentration fields with in the boundary layer have been examined with the help of graphs.

Pressure Distributions and Forces on Rectangular and D-shaped Cylinders

1972 ◽  
Vol 23 (1) ◽  
pp. 1-6 ◽  
Author(s):  
B R Bostock ◽  
W A Mair
Keyword(s):  
Boundary Layer ◽  
Circular Cylinder ◽  
Drag Coefficient ◽  
Pressure Distribution ◽  
Two Dimensional ◽  
Dimensional Flow ◽  
Pressure Distributions ◽  
Two Dimensional Flow ◽  
Rectangular Cylinders ◽  
Shaped Section

SummaryMeasurements in two-dimensional flow on rectangular cylinders confirm earlier work of Nakaguchi et al in showing a maximum drag coefficient when the height h of the section (normal to the stream) is about 1.5 times the width d. Reattachment on the sides of the cylinder occurs only for h/d < 0.35.For cylinders of D-shaped section (Fig 1) the pressure distribution on the curved surface and the drag are considerably affected by the state of the boundary layer at separation, as for a circular cylinder. The lift is positive when the separation is turbulent and negative when it is laminar. It is found that simple empirical expressions for base pressure or drag, based on known values for the constituent half-bodies, are in general not satisfactory.

Theory of the Slat in a Two-Dimensional Flow

1936 ◽  
Vol 40 (310) ◽  
pp. 681-708
Author(s):  
V. V. Golubev
Keyword(s):  
Boundary Layer ◽  
Two Dimensional ◽  
Marked Influence ◽  
Dimensional Flow ◽  
Two Dimensional Flow ◽  
Important Progress

The theory of the aerofoil has now been studied to such an extent that, from this province, it is hardly possible to expect further material improvement in its aerodynamical qualities : profiles differing but little from an inverse of a parabola (Joukovski profile) would appear to be the theoretical ideal. Subsequent important progress in that respect may be sought only in another direction, viz., in the application of a series of supplementary contrivances having a marked influence on the properties of the flow around the aerofoil. Here we are referring to such devices as the sucking away of the boundary layer (Absaugeflügel), or the insertion of appliances on the aerofoil itself. Nevertheless, up to the present, only one of the very earliest attempts in this direction, namely, the slotted wing, has developed sufficiently to be in any way widely adopted in contemporary aircraft construction.

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