High-power contactor is a key control and protection component of a aircraft power distribution system. Contactors working in high-altitude environments with thin air are more prone to overheating problems due to reduced convection. In this paper

in accordance with a certain type of high-power DC contactor for aviation

an electric-heat-gas multiphysics coupling model is established to study the heat dissipation characteristics of the contactor. On this basis

in order to improve the calculation efficiency

a thermoelectric-coupling calculation method based on the convection coefficient iteration is proposed. Compared with the experimental results

the calculation method can be used to reduce the calculation time of the contactor to 1/20 under the condition that the accuracy is basically unchanged. After this method is used to calculate the temperature field distribution in a low-pressure environment

the relative error between the results and the temperature rise experimental data is 1.81%

verifying the effectiveness of the method. Thereby

the thermal characteristics of aviation contactors under different altitudes are studied. The results show that the temperature at the outlet of the contactor increases first and then decreases with increasing altitude

and the temperature rise continues to increase. The research results of this paper can also provide references for the analysis and design of other aviation power equipment.