New Higher-Order Boundary-Layer Equations for Laminar and Turbulent Flow Past Axisymmetric Bodies.

1982 ◽  
Author(s):  
C. Kleinstreuer ◽  
A. Eglima ◽  
J. E. Flaherty
Keyword(s):  
Boundary Layer ◽  
Turbulent Flow ◽  
Higher Order ◽  
Boundary Layer Equations ◽  
Flow Past ◽  
Laminar And Turbulent Flow ◽  
Axisymmetric Bodies

Thermophoretic Deposition of Particles in Natural Convection Flow From a Vertical Plate

1985 ◽  
Vol 107 (2) ◽  
pp. 272-276 ◽  
Author(s):  
M. Epstein ◽  
G. M. Hauser ◽  
R. E. Henry
Keyword(s):  
Boundary Layer ◽  
Turbulent Flow ◽  
Simple Expression ◽  
Convection Flow ◽  
Convection Boundary Layer ◽  
Boundary Layer Equations ◽  
Fixed Set ◽  
Laminar And Turbulent Flow ◽  
The Heat Transfer Coefficient ◽  
Free Convection Boundary Layer

An analysis is made for thermophoretic transport of small particles through a free-convection boundary layer adjacent to a cold, vertical deposition surface. The gas-particle, boundary layer equations are solved numerically for both laminar and turbulent flow. The numerical results indicate that, for a fixed set of boundary conditions and physical properties, the particle concentration at the wall in the laminar flow is very close to that in turbulent flow. A simple expression is suggested relating the particle transport rate to the heat transfer coefficient for the laminar and turbulent flow regimes.

Laminar and Turbulent Flow Past a Hydrofoil Predicted by a Distributed Vorticity Method

2020 ◽  
Author(s):  
Chunlin Wu ◽  
Spyros A. Kinnas
Keyword(s):  
Turbulent Flow ◽  
Eddy Viscosity ◽  
Current Method ◽  
Reynolds Numbers ◽  
Synchronous Communication ◽  
Coupling Scheme ◽  
Computational Domain ◽  
Computationally Efficient ◽  
Flow Past ◽  
Laminar And Turbulent Flow

Abstract A distributed viscous vorticity equation (VISVE) method is presented in this work to simulate the laminar and turbulent flow past a hydrofoil. The current method is proved to be more computationally efficient and spatially compact than RANS (Reynolds-Averaged Navier-Stokes) methods since this method does not require unperturbed far-field boundary conditions, which leads to a small computational domain, a small number of mesh cells, and consequently much less simulation time. To model the turbulent flow, a synchronous coupling scheme is implemented so that the VISVE method can resolve the turbulent flow by considering the eddy viscosity in the vorticity transport equation, and the eddy viscosity is obtained by coupling VISVE with the existing turbulence model of OpenFOAM, via synchronous communication. The proposed VISVE method is applied to simulate both the laminar flow at moderate Reynolds numbers and turbulent flow at high Reynolds numbers past a hydrofoil. The velocity and vorticity calculated by the coupling method agree well with the results obtained by a RANS method.

Assessment of Real Gas Effects on Approximate and Boundary Layer Equations for Hypersonic Laminar Flow over Axisymmetric Bodies

2014 ◽  
Vol 1016 ◽  
pp. 534-539
Author(s):  
Ramin Kamali Moghadam ◽  
Seyed Amir Hosseini
Keyword(s):  
Boundary Layer ◽  
Body Region ◽  
Integral Matrix ◽  
Real Gas ◽  
Boundary Layer Equations ◽  
Blunt Bodies ◽  
Real Gas Effects ◽  
Efficient Code ◽  
Computational Procedures ◽  
Axisymmetric Bodies

Two efficient computational procedures based on the boundary layer equations and approximate relations areassessedin prediction of the laminar hypersonic flowfield for both the perfect gas and equilibrium air around the axisymmetric blunt body configurations. For the boundary layer procedure, the boundary layer equationsutilize the integral matrix solution algorithm for the blunt nose and after body region by using a space marching technique. The integral matrix procedure able us to create accurate and smooth results using the minimum grid in the boundary layer and minimize the computational costs. Applying the approximate method creates a robust and efficient code for heating calculations over the blunt bodies which flies in hypersonic regimes. These algorithms are highly appropriate to design of hypersonic reentry vehicles. The effects of real gas on the flowfield characteristics are also studied in two procedures.

scholarly journals On the solution of the laminar boundary layer equations.

1938 ◽  
Vol 164 (919) ◽  
pp. 547-579 ◽  
Author(s):  
Leslie Howarth ◽  
Leonard Bairstow
Keyword(s):  
Boundary Layer ◽  
Circular Cylinder ◽  
Pressure Distribution ◽  
Elliptic Cylinder ◽  
Accurate Solution ◽  
Boundary Layer Equations ◽  
Flow Past ◽  
Method Of Solution ◽  
Calculated Distribution ◽  
Accelerated Flow

For some years after its suggestion an approximate method of solution of the boundary layer equations due to Kármán and Pohlhausen was thought to be reasonably accurate. The present writer (1934) recommended it for general use because it agreed with experiment as far as the point of separation for the flow past a circular cylinder (when the observed pressure distribution was used in the theoretical solution). There seems to be little doubt that this method gives a reasonably accurate solution in a region of accelerated flow, but more recently its adequacy in a region of retarded flow has been questioned. The flow past a circular cylinder is not an exhaustive test for a retarded region because the pressure rises very rapidly from its minimum value leaving little doubt as to the position of separation. Schubauer (1935) has measured the pressure distribution around an elliptic cylinder of fineness ratio 2∙96:1 and also observed, by introducing smoke just beyond the separation point, the actual position of separation. On applying Pohlhausen’s method to his observed pressure distribution Schubauer fails to find any separation at all. By measurements of the velocity distribution in the boundary layer he finds that Pohlhausen’s method agrees reasonably with the observed one up to a point about five-sevenths of the way between the pressure minimum and the observed point of separation; the calculated distribution then diverges from the observed one.

scholarly journals Sensitivity of aerodynamic forces in laminar and turbulent flow past a square cylinder

2014 ◽  
Vol 26 (10) ◽  
pp. 104101 ◽  
Author(s):  
Philippe Meliga ◽  
Edouard Boujo ◽  
Gregory Pujals ◽  
François Gallaire
Keyword(s):  
Turbulent Flow ◽  
Square Cylinder ◽  
Aerodynamic Forces ◽  
Flow Past ◽  
Laminar And Turbulent Flow

Navier-Stokes solution of complete turbulent flow past finite axisymmetric bodies

AIAA Journal ◽  
1991 ◽  
Vol 29 (6) ◽  
pp. 998-1001 ◽  
Author(s):  
Seok Ki Choi ◽  
Ching Jen Chen
Keyword(s):  
Turbulent Flow ◽  
Navier Stokes ◽  
Flow Past ◽  
Axisymmetric Bodies
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