Numerical solutions of the supersonic, laminar flow over a two-dimensional compression corner

Author(s):  
James E. Carter
1960 ◽  
Vol 7 (1) ◽  
pp. 53-80 ◽  
Author(s):  
Hiroshi Sato

A study was made of the transition of a two-dimensional jet. In the region where laminar flow becomes unstable, two kinds of sinusoidal velocity fluctuation have been found; one is symmetrical and the other is anti-symmetrical with respect to the centre line of the jet. The fluctuations grow exponentially at first and develop into turbulence without being accompanied by abrupt bursts or turbulent spots.The response characteristics of laminar jets to artificial external excitation were investigated in detail by using sound as an exciting agent. The effect of excitation was seen to be most remarkable when the frequency of excitation coincides with that of self-excited sinusoidal fluctuations.Numerical solutions of equation of small disturbances superposed on laminar flow were obtained assuming the Reynolds number as infinity. Theoretical eigenvalues and eigenfunctions are in good agreement with experimental results, thus verifying the existence of a region of linear disturbance in the two-dimensional jet.


2002 ◽  
Vol 29 (3) ◽  
pp. 436-447 ◽  
Author(s):  
Y Yang ◽  
A G Straatman ◽  
R J Martinuzzi ◽  
E K Yanful

The evolution to fully developed laminar flow in low aspect ratio, two-dimensional, lid-driven cavities has been studied experimentally and numerically. Velocity measurements were made in water in a moving-lid apparatus using a laser Doppler velocimeter (LDV). Numerical solutions for the cavity flow were obtained by solving the two-dimensional mass-momentum equation set in a finite-volume framework. The measured and predicted results were in excellent agreement. Fully developed cavity flow is said to exist when the main regions of the flow field become independent of the aspect ratio. When fully developed conditions prevail, a region of countercurrent flow (CCF) separates the end structures, which are decoupled. The extent of the end regions is shown to grow linearly with increasing Reynolds number Re, based on the lid speed and the cavity height. Consequently, the critical aspect ratio for the onset of fully developed flow is also linearly dependent on Re. Above a critical Reynolds number, Re [Formula: see text] 300, the flow becomes unsteady, and a lower-wall, tertiary vortex appears, which is thought to be associated with the onset of hydrodynamic instability.Key words: lid-driven cavity, laminar flow, shallow water cover, countercurrent flow.


1964 ◽  
Vol 15 (3) ◽  
pp. 299-310 ◽  
Author(s):  
Thein Wah

SummaryThe flow in a two-dimensional channel with porous walls through which fluid is uniformly injected or extracted is considered. Following Berman, a solution is obtained giving a fourth-order non-linear differential equation which depends on a suction Reynolds number R. Numerical solutions of this equation have been obtained. Series solutions of this equation for small and large Reynolds number are given and are shown to give good agreement with the numerical solutions.


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