TY - JOUR

T1 - Aspect ratio effects on bottom heated 2D cavity using energy streamlines and field synergy principle

AU - Rani, H. P.

AU - Narayana, null

AU - Rameshwar, Y.

AU - Starchenko, S. V.

N1 - Publisher Copyright: © 2020 Plapiqu. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/1/1

Y1 - 2020/1/1

N2 - 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 10(3) to 10(6). 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.

AB - 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 10(3) to 10(6). 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.

KW - Energy streamlines

KW - Field synergy angle

KW - MPI

KW - NATURAL-CONVECTION

KW - RECTANGULAR ENCLOSURES

KW - BOUNDARY-CONDITIONS

KW - Field synergy an-gle

UR - http://www.scopus.com/inward/record.url?scp=85089009137&partnerID=8YFLogxK

M3 - Article

VL - 50

SP - 41

EP - 46

JO - Latin american applied research

JF - Latin american applied research

SN - 0327-0793

IS - 1

ER -