Numerical study on the effect of strategically placed multiple diathermal obstructions within a porous enclosure

A novel strategy to reduce the convection heat transfer across a differentially heated, fluid-saturated porous enclosure has been reported in the present investigation. This objective is achieved by sequentially and strategically embedding multiple diathermal obstructions within the enclosure. To describe it in short, the strategy is to identify the location of maximum convection strength and place a single obstruction at that location. This strategy is re-applied to find an updated location of maximum convection strength and placing another single obstruction at that newly updated location. Darcy flow model is used to describe the fluid flow in porous media and solved using Successive Accelerated Replacement scheme using finite difference method. The parameters under study are type of obstructions (horizontal, vertical, right-inclined, left-inclined, straight-crossed and inclined-crossed), number of obstructions (0 ⩽ 𝑁 ⩽ 10) and modified Rayleigh number (100 ⩽ 𝑅𝑎 ⩽ 2000). The size of obstruction (𝑍) has been fixed at 0.1. Flow and temperature distribution are plotted using streamlines and isotherms. The strength of convection is quantified using Nusselt number and maximum absolute stream function. It has been found that introducing obstructions within a differentially heated porous enclosure weakens the convection strength developed within it and the maximum reduction can be obtained for inclined-cross obstruction.

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Opracowanie rekordu ze środków MNiSW, umowa nr POPUL/SP/0154/2024/02 w ramach programu "Społeczna odpowiedzialność nauki II" - moduł: Popularyzacja nauki (2025)