Flow behind the boundary layer separation point in a supersonic stream

1973 ◽  
Vol 6 (3) ◽  
pp. 378-384 ◽  
Author(s):  
V. Ya. Neiland
Keyword(s):  
Boundary Layer ◽  
Boundary Layer Separation ◽  
Separation Point ◽  
Supersonic Stream ◽  
Layer Separation

Detecting boundary-layer separation point with a micro shear stress sensor array

2007 ◽  
Vol 139 (1-2) ◽  
pp. 31-35 ◽  
Author(s):  
Kui Liu ◽  
Weizheng Yuan ◽  
Jinjun Deng ◽  
Binghe Ma ◽  
Chengyu Jiang
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Sensor Array ◽  
Boundary Layer Separation ◽  
Separation Point ◽  
Stress Sensor ◽  
Layer Separation ◽  
Shear Stress Sensor

Semiempirical method of estimating the heat transfer level behind the boundary-layer separation point

1984 ◽  
Vol 47 (4) ◽  
pp. 1134-1139 ◽  
Author(s):  
A. I. Leont'ev ◽  
V. I. Ivin ◽  
L. V. Grekhov
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Semiempirical Method ◽  
Boundary Layer Separation ◽  
Separation Point ◽  
Layer Separation

On quasi-steady boundary-layer separation in supersonic flow. Part 2. Downstream moving separation point

2020 ◽  
Vol 900 ◽  
Author(s):  
A. I. Ruban ◽  
A. Djehizian ◽  
J. Kirsten ◽  
M. A. Kravtsova
Keyword(s):  
Boundary Layer ◽  
Supersonic Flow ◽  
Boundary Layer Separation ◽  
Separation Point ◽  
Layer Separation ◽  
Flow Part ◽  
Image Position

Abstract

scholarly journals On unsteady boundary-layer separation in supersonic flow. Part 1. Upstream moving separation point

2011 ◽  
Vol 678 ◽  
pp. 124-155 ◽  
Author(s):  
A. I. RUBAN ◽  
D. ARAKI ◽  
R. YAPALPARVI ◽  
J. S. B. GAJJAR
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Supersonic Flow ◽  
Body Surface ◽  
Boundary Layer Separation ◽  
The Body ◽  
Separation Point ◽  
Coordinate Frame ◽  
Characteristic Time Scale ◽  
Layer Separation

This study is concerned with the boundary-layer separation from a rigid body surface in unsteady two-dimensional laminar supersonic flow. The separation is assumed to be provoked by a shock wave impinging upon the boundary layer at a point that moves with speed Vsh along the body surface. The strength of the shock and its speed Vsh are allowed to vary with time t, but not too fast, namely, we assume that the characteristic time scale t ≪ Re−1/2/Vw2. Here Re denotes the Reynolds number, and Vw = −Vsh is wall velocity referred to the gas velocity V∞ in the free stream. We show that under this assumption the flow in the region of interaction between the shock and boundary layer may be treated as quasi-steady if it is considered in the coordinate frame moving with the shock. We start with the flow regime when Vw = O(Re−1/8). In this case, the interaction between the shock and boundary layer is described by classical triple-deck theory. The main modification to the usual triple-deck formulation is that in the moving frame the body surface is no longer stationary; it moves with the speed Vw = −Vsh. The corresponding solutions of the triple-deck equations have been constructed numerically. For this purpose, we use a numerical technique based on finite differencing along the streamwise direction and Chebyshev collocation in the direction normal to the body surface. In the second part of the paper, we assume that 1 ≫ Vw ≫ O(Re−1/8), and concentrate our attention on the self-induced separation of the boundary layer. Assuming, as before, that the Reynolds number, Re, is large, the method of matched asymptotic expansions is used to construct the corresponding solutions of the Navier–Stokes equations in a vicinity of the separation point.

Detection of the boundary-layer separation point based on the flexible sensor arrays

2007 ◽  
Vol 14 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Kui Liu ◽  
Wei-zheng Yuan ◽  
Jin-jun Deng ◽  
Bing-he Ma ◽  
Cheng-yu Jiang
Keyword(s):  
Boundary Layer ◽  
Sensor Arrays ◽  
Boundary Layer Separation ◽  
Separation Point ◽  
Flexible Sensor ◽  
Layer Separation

The boundary layer separation from streamlined surfaces and new ways of its prevention in diffusers

2017 ◽  
Author(s):  
Arkady Zaryankin ◽  
Andrey Rogalev ◽  
Ivan Komarov ◽  
V. Kindra ◽  
S. Osipov
Keyword(s):  
Boundary Layer ◽  
Boundary Layer Separation ◽  
Layer Separation

scholarly journals Leading Edge Blowing to Mimic and Enhance the Serration Effects for Aerofoil

2021 ◽  
Vol 11 (6) ◽  
pp. 2593
Author(s):  
Yasir Al-Okbi ◽  
Tze Pei Chong ◽  
Oksana Stalnov
Keyword(s):  
Boundary Layer ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Boundary Layer Separation ◽  
Shear Instability ◽  
Vortical Flow ◽  
High Angle ◽  
High Angle Of Attack ◽  
Layer Separation ◽  
Aerodynamic Performances

Leading edge serration is now a well-established and effective passive control device for the reduction of turbulence–leading edge interaction noise, and for the suppression of boundary layer separation at high angle of attack. It is envisaged that leading edge blowing could produce the same mechanisms as those produced by a serrated leading edge to enhance the aeroacoustics and aerodynamic performances of aerofoil. Aeroacoustically, injection of mass airflow from the leading edge (against the incoming turbulent flow) can be an effective mechanism to decrease the turbulence intensity, and/or alter the stagnation point. According to classical theory on the aerofoil leading edge noise, there is a potential for the leading edge blowing to reduce the level of turbulence–leading edge interaction noise radiation. Aerodynamically, after the mixing between the injected air and the incoming flow, a shear instability is likely to be triggered owing to the different flow directions. The resulting vortical flow will then propagate along the main flow direction across the aerofoil surface. These vortical flows generated indirectly owing to the leading edge blowing could also be effective to mitigate boundary layer separation at high angle of attack. The objectives of this paper are to validate these hypotheses, and combine the serration and blowing together on the leading edge to harvest further improvement on the aeroacoustics and aerodynamic performances. Results presented in this paper strongly indicate that leading edge blowing, which is an active flow control method, can indeed mimic and even enhance the bio-inspired leading edge serration effectively.

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