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Use of baffles in jet impingement systems in presence of initial cross-flow disturbs boundary layer that results in rise in heat transfer. Two configurations of baffle assisted impingement systems were considered and a comparative study on heat transfer and pressure drop is carried out based on operating parameters such as baffle clearance, blow ratio and h/D ratio using commercially available CFD package. Numerical predictions showed that both heat transfer and pressure drop in segmented configuration were higher than louvered configuration for all blow ratio employed in this study. Parametric studies showed that, thermo-hydraulic performance parameter is higher only for louvered configurations at low blow ratio. When cross-flow velocity is comparable with jet velocity, segmented baffles resulted in relatively higher thermo-hydraulic performance because of its higher heat transfer rate relative to the incurring pressure drop. An increase in clearance proportionally increases performance parameter. However, as jet to plate distance increases, thermo hydraulic performance declines significantly.

The objective of this research is to numerically investigate heat transfer and pressure drop characteristic of a baffle assisted multi-jet impingement of air on a heated plate subjected to constant heat flux and cross flow. Two baffle configurations were considered for the present study. An array of jets with 3 x 3 configurations discharging from round orifices of diameter D=5 mm and with jet-to-heated plate distance ranging from 2D to 3.5D were studied. SST k-ω turbulence model was used for numerical simulation to examine the effect of blow ratio and baffle clearance on heat transfer and pressure drop characteristics. Blow ratios of 0.25, 0.5, 0.75 and 1.0 and baffle clearances of 1 mm, 2 mm, and 3mm were considered for CFD simulations. The split baffle configuration with baffle clearance of 3 mm is found to be more advantageous when both heat transfer and pressure drop are considered. However, the segmented baffle configuration with a baffle clearance of 1 mm gave better results for heat transfer alone. The present study also deals with determination of optimal operating parameters with the help of Genetic Algorithm and Artificial Neural Network. A pareto front was obtained for selecting the desired value of heat transfer or pressure drop. It was found that Artificial Neural Network based predictions strongly agree with CFD simulation results, and hence seems to be very useful in arriving at the optimum values of operating parameters.

The objective of this research is to numerically investigate heat transfer characteristic of a louvered baffle assisted multi-jet impingement of air on a heated plate subjected to constant heat flux and cross flow. Two h/d configurations were considered for the present study. An array of jets with 3 x 3 configurations discharging from round orifices of diameter d=5 mm and with jet-to-target plate distance ranging from 2d to 3 d were studied. SST k-ω turbulence model was used for numerical simulation to examine the effect of blow ratio, louver angle and baffle clearance on heat transfer. Blow ratios of 0.25, 0.5, 075 and 1.0 and louver angle 30°, 45° and 60° were considered for CFD simulations. In all the cases, heat transfer increases with blow ratio and blow ratio with 1 has the maximum heat transfer. It is also noticed that heat transfer rate increases with decrease in louver angle h/d ratio.

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