Heat transfer uniformity analysis of floatation nozzle using a revised uniformity indicator

Abstract Floatation nozzle is a key component for manufacturing high performance substrates because it can support the substrate without contact. The increase of the heat transfer uniformity can improve the product quality, reduce thermal stress, etc., however, the lack of the uniformity performance indicator hinders the selection of the floatation nozzle type. In this study, the revised heat transfer and pressure uniformity indicators for distinguishing different direction are proposed. The results of the two typical impinging jet systems including slot jet and multiple circle jets show that the accuracy of the revised uniformity indicator is increased by 55.56% as compared with the traditional uniformity indicator. Then, we compare the performance of different type of floatation nozzles using the revised indicators. We find that the main factors affecting the heat transfer and pressure uniformity are the edge effects, the turbulent intermittence, and the interaction between adjacent jets. It is found that the comprehensive performance of the floatation nozzle with effusion holes is better than that of the floatation nozzle with injection holes and traditional floatation nozzle.