Structural Optimization Design of Evaporator Tube for Micro Turbojet Engine Based on Genetic Algorithm

To solve the problems of poor fuel atomization effect, low combustion efficiency, and uneven temperature distribution of the evaporator tube of a certain micro turbojet engine, a structural optimization design method based on a genetic algorithm is proposed. Taking the inner diameter of the evaporator tube, the diameter of the nozzle hole, the number of nozzle holes as design variables, the fuel atomization particle size (d50), combustion efficiency (η), and maximum wall temperature (Tmax) as optimization objectives, a multi-objective optimization mathematical model is established. The iterative optimization is carried out through the selection, crossover, and mutation operations of the genetic algorithm, and the optimization effect is verified by combining CFD (Computational Fluid Dynamics) numerical simulation. The results show that when the inner diameter of the evaporator tube is 2.6 mm, the diameter of the nozzle hole is 0.8 mm and the number of nozzle holes is eight, the fuel atomization particle size of the evaporator tube is reduced by 18.3%, the combustion efficiency is increased by 7.6%, and the maximum wall temperature is decreased by 12.4%, which significantly improves the working performance of the evaporator tube and provides an effective reference for the optimization design of key components of micro turbojet engines.