Abstract: The paper presented on this study is to represent a scaled up model of jet impingement within channel using single array nozzle pattern. The motivation behind this experiment is that to achieve effective internal cooling and improve the thermal efficiency of gas turbine. The goal of this experiment is to optimize the heat transfer enhancement of the different impingement test sections. Two experimental cases for the analysis using flat test plate and dimple plate surface. The heat transfer rate is increased by making the dimple surfaces on the plate. In the similar way we can study effect of varying aspect ratio and inclination of the plate. For the single array three aspect ratios are 2.5, 3.3 and 4.6 with six reynolds numbers 5000, 6000, 7000, 8000, 9000 and 10000 are investigated. The test is also carried out for inclined test surface with 2.5?inclination. The exit of jets in three different outflow orientations from impingement channel creates different cross flow effects. However attention is focused on outflow passes out in both directions. Detailed local nusselt number distribution is presented and compared for each case. Span-wise averaged heat transfer coefficients are plotted and compared. Data analysis indicates that for the three aspect ratios, A/R=4.6 produces higher heat transfer coefficients, the varying diameter of dimples produces higher heat transfer coefficient at large reynolds number.

Keywords: Jet impingement, heat transfer, dimples, aspect ratio, reynolds number, nusselt number.