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ABSTRACT
The present study reports an optimized configuration of multijets impinging through porous passages, providing a viable solution for applications requiring localized heat transfer. The cascaded collision lattice Boltzmann numerical method is initially validated with the in-house experimental results of single jet impinging through a porous passage configuration. A multiobjective optimization study using Kriging-GA algorithm is conducted on a single jet impinging through a porous passage at a Reynolds number of 400, considering Darcy number, porosity, and porous passage height as variables and Nusselt number, nondimensional pressure drop as the conflicting objectives. The optimal parameters from the generated pareto plot are chosen attributing equal weightage to Nusselt number and nondimensional pressure drop. Finally, an optimal pitch for multijets impinging through optimized porous passages is determined to maximize heat transfer performance.
Nomenclature
| Da | = | Darcy number |
| F | = | body force (N) |
| fi | = | density distribution function |
| gfi | = | fluid temperature distribution function |
| gsi | = | solid temperature distribution function |
| hv | = | interfacial heat transfer coefficient (W/m2/K) |
| kef | = | effective thermal conductivity of the fluid (W/m K) |
| kf | = | thermal conductivity of the fluid (W/m K) |
| ks | = | thermal conductivity of the solid (W/m K) |
| kes | = | effective thermal conductivity of the solid (W/m K) |
| K | = | permeability (m2) |
| Nuf | = | local Nusselt number of fluid phase |
| Nus | = | local Nusselt number of solid phase |
| = | average fluid Nusselt number | |
| = | average solid Nusselt number (-) | |
| ΔP* | = | dimensionless pressure drop, ΔP* = ΔP/ρu2 |
| Re | = | Reynolds number, |
| u | = | velocity of the jet (m/s) |
| W | = | width of the jet (m) |
| w | = | weight |
| Greek symbols | ||
| αef | = | effective thermal diffusivity of fluid (m2/s) |
| αes | = | effective thermal diffusivity of solid (m2/s) |
| αf | = | thermal diffusivity of fluid (m2/s) |
| ϵ | = | porosity |
| ν | = | kinematic viscosity of the fluid (m2/s) |
Nomenclature
| Da | = | Darcy number |
| F | = | body force (N) |
| fi | = | density distribution function |
| gfi | = | fluid temperature distribution function |
| gsi | = | solid temperature distribution function |
| hv | = | interfacial heat transfer coefficient (W/m2/K) |
| kef | = | effective thermal conductivity of the fluid (W/m K) |
| kf | = | thermal conductivity of the fluid (W/m K) |
| ks | = | thermal conductivity of the solid (W/m K) |
| kes | = | effective thermal conductivity of the solid (W/m K) |
| K | = | permeability (m2) |
| Nuf | = | local Nusselt number of fluid phase |
| Nus | = | local Nusselt number of solid phase |
| = | average fluid Nusselt number | |
| = | average solid Nusselt number (-) | |
| ΔP* | = | dimensionless pressure drop, ΔP* = ΔP/ρu2 |
| Re | = | Reynolds number, |
| u | = | velocity of the jet (m/s) |
| W | = | width of the jet (m) |
| w | = | weight |
| Greek symbols | ||
| αef | = | effective thermal diffusivity of fluid (m2/s) |
| αes | = | effective thermal diffusivity of solid (m2/s) |
| αf | = | thermal diffusivity of fluid (m2/s) |
| ϵ | = | porosity |
| ν | = | kinematic viscosity of the fluid (m2/s) |