Characteristics of flow past elongated bluff bodies with underbody gaps due to varying inflow turbulence

2021 ◽  
Vol 33 (12) ◽  
pp. 125106
Author(s):  
Seyed Sobhan Aleyasin ◽  
Mark Francis Tachie ◽  
Ram Balachandar
Keyword(s):  
Bluff Bodies ◽  
Flow Past ◽  
Inflow Turbulence

Discussion of “Effect of Side Walls on Flow Past Bluff Bodies”

1971 ◽  
Vol 97 (10) ◽  
pp. 1782-1787
Author(s):  
B. C. Syamala Rao ◽  
D. V. Chandrasekhara
Keyword(s):  
Bluff Bodies ◽  
Flow Past ◽  
Side Walls

An approximate theory for the streaming motion past axisymmetric bodies at Reynolds numbers of from 1 to approximately 100

1977 ◽  
Vol 82 (3) ◽  
pp. 583-604 ◽  
Author(s):  
Michael S. Kolansky ◽  
Sheldon Weinbaum ◽  
Robert Pfeffer
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Pressure Gradient ◽  
Reynolds Numbers ◽  
Bluff Bodies ◽  
Approximate Theory ◽  
Viscous Term ◽  
Number Range ◽  
Curvature Effects ◽  
Flow Past

In Weinbaum et al. (1976) a simple new pressure hypothesis is derived which enables one to take account of the displacement interaction, the geometrical change in streamline radius of curvature and centrifugal effects in the thick viscous layers surrounding two-dimensional bluff bodies in the intermediate Reynolds number range O(1) < Re < O(102) using conventional Prandtl boundary-layer equations. The new pressure hypothesis states that the streamwise pressure gradient as a function of distance from the forward stagnation point on the displacement body is equal to the wall pressure gradient as a function of distance along the original body. This hypothesis is shown to be equivalent to stretching the streamwise body co-ordinate in conventional first-order boundary-layer theory. The present investigation shows that the same pressure hypothesis applies for the intermediate Reynolds number flow past axisymmetric bluff bodies except that the viscous term in the conventional axisymmetric boundary-layer equation must also be modified for transverse curvature effects O(δ) in the divergence of the stress tensor. The approximate solutions presented for the location of separation and the detailed surface pressure and vorticity distribution for the flow past spheres, spheroids and paraboloids of revolution at various Reynolds numbers in the range O(1) < Re < O(102) are in good agreement with available numerical Navier–Stokes solutions.

On the theory of hypersonic flow past plane and axially symmetric bluff bodies

1956 ◽  
Vol 1 (4) ◽  
pp. 366-387 ◽  
Author(s):  
N. C. Freeman
Keyword(s):  
Hypersonic Flow ◽  
The Body ◽  
Successive Approximations ◽  
Method Of Successive Approximations ◽  
Radius Of Curvature ◽  
Bluff Bodies ◽  
Axially Symmetric ◽  
Nose Radius ◽  
Flow Past ◽  
Past Plane

The ‘Newtonian-plus-centrifugal’ approximate solution (Busemann (1933) and Ivey (1948)) for hypersonic flow past plane and axially symmetric bluff bodies in gases with the ratio of the specific heats λ constant and equal to unity is rederived using ‘boundary layer’ techniques together with the von Mises variables x and ψ. A method of successive approximations then gives a closer approximation to this solution for ε (λ − 1)/(λ + 1) small and the free-strea Mach number infinite. Formulae for the streamlines, shock shape and pressure distribution are determined to this approximation. These formulae are valid for any plane or axially symmetric shape, giving the ‘stand-off’ distance of the shock wave from the body as ½εlog(4|3ε) and ε times the nose radius of curvature for plane and axially-symmetric flows respectively. Particular results are computed for a number of special shapes. For certain shapes, the theory has a singular point where the first approximation to the pressure vanishes (θ = 60° for a sphere). Actually, the theory is not applicable where the pressure becomes too small. The corresponding theory for gases of general thermodynamic properties is deduced, the approximation being valid provided the total energy of the gas is large compared with the energy contained in the translational modes of the gas molecules.

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