In the present study, a flow visualization and heat transfer investigation is carried out computationally on a flat plate with 10×1 array of impinging jets from a corrugated plate. This corrugated structure is an Anti-Cross Flow (ACF) technique which is proved to nullify the negative effects of cross-flow thus enhancing the overall cooling performance. Governing equations are solved using k-ω Shear Stress Transport (SST) turbulence model in commercial code FLUENT. The parameter variation considered for the present study are (i) three different heights of ACF corrugate (C/D = 1, 2 & 3) and (ii) two different jet-to-target plate spacing (H/D = 1 & 2). The dependence of ACF structure performance on the corrugate height (C/D) and the flow structure has been discussed in detail, therefore choosing an optimum corrugate height and visualizing the three-dimensional flow phenomena are the main objectives of the present study. The three-dimensional flow separation and heat transfer characteristics are explained with the help of skin friction lines, upwash fountains, wall eddies, counter-rotating vortex pair (CRVP), and plots of Nusselt number. It is found that the heat transfer performance is high at larger corrugate heights for both the jet-to-plate spacing. Moreover, the deterioration of the skin friction pattern corresponding to the far downstream impingement zones is greatly reduced with ACF structure, retaining more uniform heat transfer pattern even at low H/D values where the crossflow effects are more dominant in case of the conventional cooling structure. In comparison of the overall heat transfer performance the difference between C/D = 3 & C/D = 2 for H/D = 2 is significantly less, thus making the later as the optimal configuration in terms of reduced channel height.

A flow visualization study has been carried out computationally on a flat plate with a 5 × 5 array of impinging jets for different cross-flow schemes. The k-ω SST turbulence model is used for carrying out the RANS simulations. The parameters investigated are (i) cross-flow schemes (minimum, medium & maximum), (ii) jet-to-plate spacing (H/D = 1, 2, 3 & 5) and (iii) turbulent jet Reynolds numbers (15000, 25000 & 35000). The topology and three-dimensional separation phenomena are used to explain the flow and heat transfer characteristics. The skin friction lines on the interaction surface are explained with the help of nodal points of attachment and separation, saddle point, separation, and attachment lines. It is observed that the skin friction lines change their pattern with H/D and cross-flow. Peaks in the heat transfer are observed corresponding to the impingement point and wall jet interaction points. At lower H/D values, the effect of cross-flow is more prominent. However, these effects are marginal for higher H/D values. For lower H/D, the localized heat transfer rates are high but the uniformity in heat flux is obtained with an increase in H/D. In maximum and medium cross-flow cases, the heat transfer pattern changes with the distance from the center of the plate. It is found that the flow structure on the surface is independent of the jet Reynolds number.

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