小型航空Wankel发动机转子结构优化仿真

三角转子是小型航空Wankel转子发动机的核心部件，其高速旋转过程中承受着温度、惯性力和燃气爆发压力等复杂载荷耦合作用，更加容易因强度不足发生失效与破坏。针对多重载荷耦合工况下，三角转子应力集中与强度问题，建立发动机热力学模型，获得发动机单循环内燃烧室缸温、缸压以及换热系数变化曲线，计算转子各处热边界条件，分别在机械应力、热应力与热 机械耦合条件下，采用有限元的方法对三角转子进行温度场、应力场与变形量仿真分析，并提出转子腰部圆孔边缘处加工圆角和冷却孔处布置散热片优化方法。仿真结果表明：优化后三角转子最大应力由原来的687.0 MPa下降为403.9 MPa，约为原来的58.79%；转子腰部圆孔边缘应力由577.5 MPa下降为306.1 MPa，降低为原来的53.02%；冷却孔处应力值也由212.6 MPa降至113.2 MPa，约为原来的53.25%。布置散热片后，转子平均温度下降20 K以上，转子腰部圆孔边缘与冷却孔温度下降40 K左右，密封槽尖端变形量由0.21 mm降至0.15 mm，减小27.7%。转子应力场得到改善，变形量减小。

Research on Simulation and Optimization of Triangle Rotor of Small Aviation Wankel Engine

Triangular rotor is a core component of small aviation Wankel rotary engine, subjected to complex load coupling effects such as temperature, inertial force and gas explosion pressure in the process of high speed rotation, and more prone to failure and damage due to insufficient strength. In view of the stress concentration and strength evaluation of triangular rotor, a model of the engine''s thermodynamic working process is established to obtain the change law of the cylinder temperature, cylinder pressure and heat transfer coefficient of the combustion chamber in a single cycle of the engine,and calculate the thermal boundary conditions everywhere in the rotor.Under conditions of mechanical stress, thermal stress and thermo mechanical coupling, the finite element method is adopted respectively to simulate and analyze the temperature field, stress field and deformation of the triangular rotor. And optimization methods such as the processing of rounded corners at the edge of the round hole at the waist of the rotor and the arrangement of heat sinks at the cooling hole are proposed, and comparative analysis is carried out.The simulation results show that after the optimization, the stress at the edge of the circular hole at the waist of the rotor is reduced to 403.9 MPa from 687.0 MPa, which is about 58.7% of the original, and the stress value at the cooling hole is also reduced to 113.2 MPa from 202.6 MPa, which is 55.9% of the original. Cooling fins being arranged, a drop of rotor at temperature is more than 20 K on average, the temperature of the round hole at the waist of the rotor and the cooling hole dropped is about 40 K, and the deformation of the sealing groove tip is reduced to 0.15 mm, from 0.21 mm, i.e. a reduction of 27.7%.