What is the influence of lattice Pore size and shape on heat transfer?
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The influence of lattice pore size and shape on heat transfer is significant in various porous media studies. Different shapes like square, circular, star, triangular, elliptical, and rectangular pores impact heat transfer differently. For instance, in metal-organic frameworks (MOFs), smaller pores experience reduced thermal conductivity due to gas-phonon scattering, while larger pores are less affected by adsorbed gas . In porous media, sharp-cornered grains induce higher reverse flow, with rectangular grains causing the least pressure drop . The thermal conductivity of porous media increases with pore alignment, where the longest principal axis enhances thermal conductivity . Additionally, using porous media enhances heat transfer rates and creates fluctuations along the wall, affecting the overall heat transfer process .
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5 Citations | The lattice Boltzmann model shows that varying pore size and shape in porous media affect heat transfer, impacting fluid flow and rock permeability due to thermal convection effects. |
46 Citations | The pore shape in porous media affects thermal conductivity, with stronger effects at higher porosities. Spherical pores maximize thermal conductivity, while longer axes enhance heat transfer. |
| Pore size affects heat transfer in metal-organic frameworks (MOFs); smaller pores enhance thermal conductivity, while larger pores show less impact due to reduced gas-crystal collisions, influencing heat transfer efficiency. | |
11 Citations | The shape of porous media grains affects heat transfer. Sharp corners increase reverse flow, rectangular shape minimizes pressure drop, and star shape extends flame length compared to elliptical and triangular shapes. |
| Pore shape affects heat transfer in a porous cavity; star-shaped pores exhibit the highest local Nusselt number peaks, while circular pores show the lowest values. Square pores follow in between. |
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What are the mechanisms of natural convection in porous media?5 answersStep 1: Answer without citation
Natural convection in porous media is influenced by the Rayleigh number, pore size, and porosity. The Darcy–Oberbeck–Boussinesq (DOB) equations are commonly used for simulations, but they do not capture the nonlinear scaling trends observed in direct numerical simulations (DNS). The Sherwood number is found to have a nonlinear relationship with the Rayleigh number, depending on porosity and pore-scale parameters. Additionally, the boundary layer thickness is determined by the pore size, contrary to previous assumptions. The study also proposes a new correlation for the Sherwood number at large Rayleigh numbers, low Darcy numbers, and high Schmidt numbers, validated across various conditions.
Step 3: Answer with citation
Natural convection in porous media is influenced by the Rayleigh number, pore size, and porosity. The Darcy–Oberbeck–Boussinesq (DOB) equations are commonly used for simulations, but they do not capture the nonlinear scaling trends observed in direct numerical simulations (DNS). The Sherwood number is found to have a nonlinear relationship with the Rayleigh number, depending on porosity and pore-scale parameters. Additionally, the boundary layer thickness is determined by the pore size, contrary to previous assumptions. The study also proposes a new correlation for the Sherwood number at large Rayleigh numbers, low Darcy numbers, and high Schmidt numbers, validated across various conditions.