JET IMPINGENT – LITERATURE REVIEW

Kurzfassung

Jet impingement cooling is an efficient method to enhance heat transfer locally. Yet, it is still possible to improve this technique by adding turbulators on the target plate. This report reviews different literature during the last decade about jet impingement cooling. The goal is to determine the benefit of jet impingement cooling combined with turbulators used to cool turbines. If not cooled, the gas turbine may be damaged. The results gathered from literature are compared to empirical correlations in order to observe the effect of turbulators on heat transfer and to determine which type of turbulators is more effective. Averaged Nusselt number, Reynolds number, and different geometrics values are gathered for different type of turbulators and are compared (smooth, ribs, pin-fins, dimples and corrugation). The form of turbulators impacts heat transfer in various ways. Pin-fins and dimples enhance heat transfer mainly by increasing the area. Ribs enhance heat transfer by increasing the area but also by guiding the flow. Depending on the form of each type of turbulator, some effects will be more or less present. In order to estimate which turbulator will offer higher heat transfer enhancement the data gathered are compared thanks to the programming language Python 3.8. It is observed that ribs and pin-fins offer better averaged Nusselt number compared to other type of turbulators at a separation distance from the target plate of 3D where D is the jet diameter. In majority of cases average Nusselt number with turbulators is higher than the average Nusselt number of the baseline, except for dimples at low Reynolds number.