Near-body vorticity dynamics of a square cylinder subjected to an inline pulsatile free stream flow

2016 ◽  
Vol 28 (9) ◽  
pp. 093605 ◽  
Author(s):  
Hrisheekesh Krishnan ◽  
Amit Agrawal ◽  
Atul Sharma ◽  
John Sheridan
Keyword(s):  
Stream Flow ◽  
Free Stream ◽  
Square Cylinder ◽  
Vorticity Dynamics

Numerical Study of the Laminar Flow Past a Rotating Square Cylinder at Low Spinning Rates

2014 ◽  
Vol 137 (2) ◽  
Author(s):  
Dipankar Chatterjee ◽  
Satish Kumar Gupta
Keyword(s):  
Rotational Speed ◽  
Stream Flow ◽  
Free Stream ◽  
Stokes Equations ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Low Frequency ◽  
Square Cylinder ◽  
Rotating Circular Cylinder ◽  
Critical Rotational Speed

The fluid dynamic interaction between a uniform free stream flow and the rotation induced flow from a sharp edged body is numerically investigated. A two-dimensional (2D) finite volume based computation is performed in this regard to simulate the laminar fluid flow around a rotating square cylinder in an unconfined medium. Body fitted grid system along with moving boundaries is used to obtain the numerical solution of the incompressible Navier–Stokes equations. The Reynolds number based on the free stream flow is kept in the range 10≤Re≤200 with a dimensionless rotational speed of the cylinder in the range 0≤Ω≤5. At low Re=10, the flow field remains steady irrespective of the rotational speed. For 50≤Re≤200, regular low frequency Kármán vortex shedding (VS) is observed up to a critical rate of rotation (Ωcr). Beyond Ωcr, the global flow shows steady nature, although high frequency oscillations in the aerodynamic coefficients are present. The rotating circular cylinder also shows likewise degeneration of Kármán VS at some critical rotational speed. However, significant differences can be seen at higher rotation. Such fluid dynamic transport around a spinning square in an unconfined free stream flow is reported for the first time.

Aspects of Shear Layer Unsteadiness in a Three-Dimensional Supersonic Wake

2005 ◽  
Vol 127 (6) ◽  
pp. 1085-1094 ◽  
Author(s):  
Alan L. Kastengren ◽  
J. Craig Dutton
Keyword(s):  
Shear Layer ◽  
Stream Flow ◽  
Free Stream ◽  
Angle Of Attack ◽  
Three Dimensional ◽  
Base Flow ◽  
Recirculation Region ◽  
Side View ◽  
Near Wake ◽  
Supersonic Wake

The near wake of a blunt-base cylinder at 10° angle-of-attack to a Mach 2.46 free-stream flow is visualized at several locations to study unsteady aspects of its structure. In both side-view and end-view images, the shear layer flapping grows monotonically as the shear layer develops, similar to the trends seen in a corresponding axisymmetric supersonic base flow. The interface convolution, a measure of the tortuousness of the shear layer, peaks for side-view and end-view images during recompression. The high convolution for a septum of fluid seen in the middle of the wake indicates that the septum actively entrains fluid from the recirculation region, which helps to explain the low base pressure for this wake compared to that for a corresponding axisymmetric wake.

scholarly journals Effect of wavelength of fish-like undulation of a hydrofoil in a free-stream flow

Sadhana ◽  
2017 ◽  
Vol 42 (4) ◽  
pp. 585-595 ◽  
Author(s):  
Thekkethil Namshad ◽  
Mukul Shrivastava ◽  
Amit Agrawal ◽  
Atul Sharma
Keyword(s):  
Stream Flow ◽  
Free Stream

A Note Related to the Pressure Inside an Inflating Parachute Canopy

1977 ◽  
Vol 28 (4) ◽  
pp. 271-277
Author(s):  
P R Payne ◽  
E G U Band
Keyword(s):  
Analytic Function ◽  
Stream Flow ◽  
Free Stream ◽  
Internal Flow ◽  
The Other ◽  
Virtual Mass ◽  
Ram Pressure ◽  
Parachute Canopy ◽  
Mass Terms ◽  
Internal Pressures

SummaryIf a canopy is idealised as a cylinder with one end open to the free-stream flow, and the other end closed, then the internal flow during inflation is given by a simple analytic function. In this note the function is derived and then the internal pressures and corresponding forces associated with inflation are determined. It is found that, in addition to ram pressure and the von Kármán “virtual mass” terms in the pressure equations, there are other transient terms associated with radial velocity and acceleration.

Numerical study on the fluid flow pass a square cylinder: The temperature-viscosity dependence

2014 ◽  
Vol 25 (03) ◽  
pp. 1350101
Author(s):  
Jianhua Lu ◽  
Sheng Li ◽  
Zhaoli Guo ◽  
Baochang Shi
Keyword(s):  
Fluid Flow ◽  
Free Stream ◽  
Numerical Study ◽  
Effect Of Temperature ◽  
Square Cylinder ◽  
Efficient Tool ◽  
Multiple Relaxation Time ◽  
Upward Velocity ◽  
Drag And Lift ◽  
Viscosity Dependence

In this paper, the 2D fluid flow pass a heated/cooled square cylinder exposed to a constant free-stream upward velocity is simulated via a multiple relaxation time (MRT) lattice-Boltzmann (LB) method. The buoyancy effect on the drag and lift coefficients as well as Nusselt number related is compared with the results in the existing literatures to validate the code used. The effect of temperature-viscosity dependence is then investigated to test whether the effect can be neglected or not for the mixed convection case. It is shown that the effect cannot be ignored when |Ri| > 0.15. Fortunately, the effect can be captured by using an effective temperature formula [J. M. Shi, D. Ferlach, M. Breuer, G. Biswas and F. Durst, Phys. Fluids16, 4331 (2004)] in a rather large range of Ri. All the numerical results, from another angle, also demonstrate that the MRT method is an efficient tool in simulating the problems such as the present one.

An Empirical Formula for Stagnation Point Velocity Gradient for Spheres and Circular Cylinders in Hypersonic Flow

1965 ◽  
Vol 69 (654) ◽  
pp. 407-408 ◽  
Author(s):  
D. R. Topham
Keyword(s):  
Stagnation Point ◽  
Velocity Gradient ◽  
Stream Flow ◽  
Free Stream ◽  
Circular Cylinders ◽  
Stream Velocity ◽  
Flow Properties ◽  
Transfer Rates ◽  
Point Velocity ◽  
Image Position

When stagnation heat transfer rates are expressed in terms of free stream flow properties, the following combination of terms is found to occur: —where ps pressure at the stagnation pointp∞free stream pressureU∞free stream velocityDnose diameterßstagnation point velocity gradient.

Unified hydrodynamics study for various types of fishes-like undulating rigid hydrofoil in a free stream flow

2018 ◽  
Vol 30 (7) ◽  
pp. 077107 ◽  
Author(s):  
Namshad Thekkethil ◽  
Atul Sharma ◽  
Amit Agrawal
Keyword(s):  
Stream Flow ◽  
Free Stream

Flow past a transversely oscillating square cylinder in free stream at low Reynolds numbers

2009 ◽  
Vol 61 (6) ◽  
pp. 658-682 ◽  
Author(s):  
A. P. Singh ◽  
A. K. De ◽  
V. K. Carpenter ◽  
V. Eswaran ◽  
K. Muralidhar
Keyword(s):  
Free Stream ◽  
Reynolds Numbers ◽  
Square Cylinder ◽  
Low Reynolds Numbers ◽  
Flow Past ◽  
Low Reynolds ◽  
Oscillating Square Cylinder
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