Multi-objective optimization of jet impingement cooling structure with smooth target surface and enhanced target surface in a limited space

In order to meet the needs of the development of multi-layer thin-walled turbine blades, this work optimizes the jet impingement cooling structure in a limited space. Firstly, the NSGA-II algorithm is used to optimize the basic structure of the target surface with the maximum heat transfer coefficient and the minimum total pressure difference as the objectives. The structural parameters considered include: the number of rows of jet holes N, jet hole diameter Dj, jet-to-target distance H/Dj and transverse distance between jet holes S/W. The interaction between the impact factors is obtained by analyzing the response surface, and the Pareto front solution set is obtained. In this solution set, design point 12 is recommended when considering both heat transfer intensity and resistance, and design point 18 is recommended when pursuing heat transfer intensity. In addition, in order to further enhance the heat transfer intensity with a small resistance cost on the basis of design point 18, a circular protrusion array enhanced structure is arranged on the target surface. Using NSGA-II algorithm, multi-objective optimization is carried out with the goal of maximum heat transfer intensity and maximum comprehensive heat transfer intensity. Compared with the design point 18, the heat transfer intensity of the optimized enhanced structure is increased by 19.4 %, the comprehensive heat transfer performance is increased by 16.6 %, and the resistance is only increased by 7.4 %.