scholarly journals Visualization Techniques of Differentially Heated Lid-Driven Square Cavity

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Vekamulla Narayana
Keyword(s):  
Flow Field ◽  
Boundary Conditions ◽  
Computational Cost ◽  
Field Synergy ◽  
Governing Equations ◽  
Square Cavity ◽  
Field Synergy Principle ◽  
Visualization Techniques

In the present study, an attempt is made to explore the flow field inside the differentially heated lid-driven square cavity. The governing equations along with boundary conditions are solved numerically. The simulated results (100 ≤ Re ≤ 1000 and 0.001 ≤ Ri ≤ 10) are validated with previous results in the literature. The convection differencing schemes, namely, UPWIND, QUICK, SUPERBEE, and SFCD, are discussed and are used to simulate the flow using the MPI code. It is observed that the computational cost for all the differencing schemes get reduced tremendously when the MPI code is implemented. Plots demonstrate the influences of Re and Ri in terms of the contours of the fluid streamlines, isotherms, energy streamlines, and field synergy principle.

scholarly journals Analysis Of Field Synergy In Bottom Heated Lid Driven Cubical Cavity

2019 ◽  
Vol 128 ◽  
pp. 07007
Author(s):  
H.P. Rani ◽  
V. Narayana ◽  
Y. Rameshwar
Keyword(s):  
Forced Convection ◽  
Computational Cost ◽  
Convection Flow ◽  
Field Synergy ◽  
Governing Equations ◽  
Field Synergy Principle ◽  
Stream Functions ◽  
Forced Convective Flow ◽  
Volume Method ◽  
Cubical Cavity

This study presents an innovative visualization tool for the analysis of the mixed convection in a lid-driven air filled cubical cavity heated from below. The total energy of the flow in the cavity isvisualized based on the energy stream functions or energy streamlines. Also the heat transfer enhancement in the cavity is presented with an analogy between conduction and convection, namely, the field synergy principle. Flow is assumed to be driven by the vertical temperature gradient and by the top lid of the cavity, which is assumed to slide on its own plane at a uniform speed. The top and bottom walls are assumed to be isothermal and all other walls are thermally insulated. Non dimensional governing equations of this problem are solved by using the finite volume method. Established open source CFD package OpenFOAM is utilized to investigate the flow with respect to the control parameters arising in the system. The nonlinear terms arising in the governing equations are discretized with the NVD schemes. The convection differencing schemes namely, UPWIND, QUICK, SUPERBEE and SFCD discussed and are used to simulate the flow using MPI code. It is observed that the computational cost for all the differencing schemes get reduced tremendously when the MPI code is implemented. Also SFCD scheme gave the Nuseelt number values close to those available in the literature. Extensive numerical flow visualization is conducted for the Reynolds number (Re = 100, 400, 1000) and the Richardson number (Ri = 0.001, 1, 10), which categorize the free and forced convective flow, respectively. It is observed that for a fixed value of Re, as Ri increases, the average Nusselt number (Nu¯), decreases. This shows that the natural convection starts to prevail with an increasing of Ri. But, for a fixed Ri, as Re increases (Nu¯) increases and the forced convection mode becomes dominant, leading to a chaotic flow. Plots demonstrating the influences of Re and Ri in termsof the contours of the fluid streamlines, isotherms, vortex corelines, and field synergy principle. The synergy angle of buoyant-aiding flow is high while the buoyant-opposing flow is significantly less than that of forced convection flow.

Subsonic Turbulent Flow Past a Planar Fence

1979 ◽  
Vol 101 (3) ◽  
pp. 373-375
Author(s):  
M. L. Agarwal ◽  
P. K. Pande ◽  
Rajendra Prakash
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Flow Field ◽  
Boundary Conditions ◽  
Mean Flow ◽  
Governing Equations ◽  
Flow Past ◽  
Entire Flow ◽  
The Mean ◽  
Shape And Size

The mean flow past a fence submerged in a turbulent boundary layer is numerically simulated. The governing equations have been simplified by neglecting the convective effects of turbulence and solved numerically using experimental boundary conditions. The information obtained includes the shape and size of the upstream and downstream separation bubbles and the streamline pattern in the entire flow field. General agreement between the simulated and the experimental flow field was found.

Lubrication Theory for Micropolar Fluids

1971 ◽  
Vol 38 (3) ◽  
pp. 646-650 ◽  
Author(s):  
S. J. Allen ◽  
K. A. Kline
Keyword(s):  
Flow Field ◽  
Differential Equations ◽  
Boundary Conditions ◽  
Two Dimensional ◽  
Slider Bearing ◽  
Governing Equations ◽  
Micropolar Fluids ◽  
Linear Ordinary Differential Equations ◽  
Two Dimensional Flow ◽  
Order Of Magnitude

The equations governing the flow of a fluid with rigid, spherical substructure are summarized. A two-dimensional flow field is considered and applied to the geometry of a slider bearing. Order-of-magnitude arguments are used which reduce the governing equations to a system of coupled, linear, ordinary differential equations. The equations are solved subject to appropriate boundary conditions and the effects of substructure discussed with the help of a specific numerical example.

Fluid flow field synergy principle and its application to drag reduction

2008 ◽  
Vol 53 (11) ◽  
pp. 1768-1772 ◽  
Author(s):  
Qun Chen ◽  
JianXun Ren ◽  
ZengYuan Guo
Keyword(s):  
Fluid Flow ◽  
Flow Field ◽  
Drag Reduction ◽  
Field Synergy ◽  
Field Synergy Principle

ASPECT RATIO EFFECTS ON BOTTOM HEATED 2D CAVITY USING ENERGY STREAMLINES AND FIELD SYNERGY PRINCIPLE

2019 ◽  
Vol 50 (1) ◽  
pp. 41-46
Author(s):  
Hari Ponnamma Rani ◽  
Narayana Vekamulla ◽  
Yadagiri Rameshwar ◽  
Sergey Vladimirovich Starchenko
Keyword(s):  
Transfer Rate ◽  
Velocity Vector ◽  
Field Synergy ◽  
Convective Term ◽  
Field Synergy Principle ◽  
Velocity Magnitude ◽  
Aspect Ratios ◽  
Vertical Walls ◽  
Higher Temperature ◽  
Visualization Techniques

In the present work free convective air flow in the two-dimensional cavity with three different aspect ratios (AR) are investigated using direct numerical simulation. The bottom wall is assumed to be kept at a uniform higher temperature than that of the top wall and the other two vertical walls are assumed to be thermally insulated. The computations are conducted for Rayleigh number (Ra) values from 103 to 106. Convective schemes are compared and Self Filtered Central Differencing Scheme is used to discretize convective term. Parallel computing MPI code is adapted to run the simulations. An attempt has been made to gather the visualization techniques such as streamlines, isotherms, energy streamlines and field synergy principle to analyse the flow behaviour inside the cavity. When Ra is small, the vertical energy streamlines are observed in the cavity. As Ra further increased, the free energy streamlines observed at the boundary and the trapped energy streamlines at the centre in the horizontal direction. For a fixed Ra, and increasing AR, the average synergy angle increases. This indicates synergy or the coordination between velocity magnitude and temperature field gets decreased and leads to the growth of heat transfer rate. The field synergy principle implies by enhancing the synergy between the velocity vector and temperature gradient.

Application of field synergy principle to analysis of flow field in underhood of LPG bus

2014 ◽  
Vol 103 ◽  
pp. 186-192
Author(s):  
Jia-Jie Ou ◽  
Li-Fu Li ◽  
Tao Cui ◽  
Zi-Ming Chen
Keyword(s):  
Flow Field ◽  
Field Synergy ◽  
Field Synergy Principle
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