A Numerical Study of Sinusoidal Oscillatory Flows Around a Vertical Wall-Mounted Circular Cylinder

A two-dimensional, mathematical model is adopted to investigate the development of buoyancy driven circulation patterns and temperature contours inside a rectangular enclosure filled with a compressible fluid (Pr=1.0). One of the vertical walls of the enclosure is kept at a higher temperature then the opposing vertical wall. The top and the bottom of the enclosure are assumed insulated. The physics based mathematical model for this problem consists of conservation of mass, momentum (two-dimensional Navier-Stokes equations) and energy equations for the enclosed fluid subjected to appropriate boundary conditions. The working fluid is assumed to be compressible through a simple ideal gas relation. The governing equations are discretized using second order accurate central differencing for spatial derivatives and first order forward finite differencing for time derivatives where the computation domain is represented by a uniform orthogonal mesh. The resulting nonlinear equations are then linearized using Newton’s linearization method. The set of algebraic equations that result from this process are then put into a matrix form and solved using a Coupled Modified Strongly Implicit Procedure (CMSIP) for the unknowns (primitive variables) of the problem. A numerical experiment is carried out for a benchmark case (driven cavity flow) to verify the accuracy of the proposed solution procedure. Numerical experiments are then carried out using the proposed compressible flow model to simulate the development of the buoyancy driven circulation patterns for Rayleigh numbers between 103 and 105. Finally, an attempt is made to determine the effect of compressibility of the working fluid by comparing the results of the proposed model to that of models that use incompressible flow assumptions together with Boussinesq approximation.

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Vortex lock-on for a rotationally oscillating circular cylinder — a BEM numerical study

Engineering Analysis with Boundary Elements ◽

10.1016/0955-7997(95)00027-l ◽

1995 ◽

Vol 15 (3) ◽

pp. 235-247 ◽

Cited By ~ 2

Author(s):

M.M. El-Refaee

Keyword(s):

Circular Cylinder ◽

Numerical Study

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An experimental and numerical study of the resonant flow between a hull and a wall

Journal of Fluid Mechanics ◽

10.1017/jfm.2021.877 ◽

2021 ◽

Vol 930 ◽

Author(s):

I.A. Milne ◽

O. Kimmoun ◽

J.M.R. Graham ◽

B. Molin

Keyword(s):

Vortex Shedding ◽

Particle Image ◽

Numerical Study ◽

Numerical Models ◽

Vertical Wall ◽

Liquefied Natural Gas ◽

Narrow Gap ◽

Image Velocimetry ◽

High Degree ◽

Wave Induced

The wave-induced resonant flow in a narrow gap between a stationary hull and a vertical wall is studied experimentally and numerically. Vortex shedding from the sharp bilge edge of the hull gives rise to a quadratically damped free surface response in the gap, where the damping coefficient is approximately independent of wave steepness and frequency. Particle image velocimetry and direct numerical simulations were used to characterise the shedding dynamics and explore the influence of discretisation in the measurements and computations. Secondary separation was identified as a particular feature which occurred at the hull bilge in these gap flows. This can result in the generation of a system with multiple vortical regions and asymmetries between the inflow and outflow. The shedding dynamics was found to exhibit a high degree of invariance to the amplitude in the gap and the spanwise position of the barge. The new measurements and the evaluation of numerical models of varying fidelity can assist in informing offshore operations such as the side by side offloading from floating liquefied natural gas facilities.

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Effect of Periodic Imposed Heat Flux on Three-Dimensional Natural Convection in a Partially Heated Cubical Enclosure

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.831.83 ◽

2016 ◽

Vol 831 ◽

pp. 83-91

Author(s):

Lahoucine Belarche ◽

Btissam Abourida

Keyword(s):

Heat Transfer ◽

Natural Convection ◽

Numerical Study ◽

Control Volume ◽

Vertical Wall ◽

Three Dimensional ◽

Maximum Temperature ◽

Cubical Enclosure ◽

Simplec Algorithm ◽

Volume Method

The three-dimensional numerical study of natural convection in a cubical enclosure, discretely heated, was carried out in this study. Two heating square sections, similar to the integrated electronic components, are placed on the vertical wall of the enclosure. The imposed heating fluxes vary sinusoidally with time, in phase and in opposition of phase. The temperature of the opposite vertical wall is maintained at a cold uniform temperature and the other walls are adiabatic. The governing equations are solved using Control volume method by SIMPLEC algorithm. The sections dimension ε = D / H and the Rayleigh number Ra were fixed respectively at 0,35 and 106. The average heat transfer and the maximum temperature on the active portions will be examined for a given set of the governing parameters, namely the amplitude of the variable temperatures a and their period τp. The obtained results show significant changes in terms of heat transfer, by proper choice of the heating mode and the governing parameters.

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