A Review of Impingement Jet Cooling in Combustor Liner

Impingement jet cooling is a promising cooling method in modern dry low emission combustor because of its high local heat transfer coefficient. This paper investigates the recent research progress on impingement jet cooling in combustor liner. Firstly, the different flow characteristics in the different impingement jet flow regions are described. Then, the factors influencing impingement jet cooling are discussed, including flow factor and geometry factor. The researches in a large range of flow parameters, including Reynolds number, Mach number and temperature ratio, are reported. The researches in different geometry parameters, such as nozzle geometry, nozzle-to-nozzle spacing, nozzle-to-target distance and inclined angle, are presented. Next, the crossflow effect in array impingement jet is considered. Due to the crossflow decreases the heat transfer performance, varieties of structures which can restrict the crossflow and improve the channel flow are introduced. Finally, the methods to enhance the impingement jet cooling are presented. These methods focus on retrofitting the nozzle and target surface. The combination of impingement jet cooling with other methods, such as effusion cooling, rib roughened surface, is important development direction in combustor liner in the future.