Modeling and simulation of thermal characteristics of aircraft hydraulic system considering heat transfer with environment

Analysis of thermal characteristics is extremely important in the design of aircraft hydraulic system, which affects the performance of oil, the efficiency of heat dissipation, the life span of components, and even the safety of aircraft. However, simulation of thermal characteristics for aircraft hydraulic system is very difficult because of the complexity of the system and the environmental variability. In this paper, a simplified thermal simulation model is established to predict the thermal characteristics of the entire hydraulic system. A new heat transfer calculation method is proposed based on engineering experience and test, including heat conduction between oil and shell and heat convection between shell and environment. Furthermore, the thermal simulation modeling method of the main hydraulic system components is established, including hydraulic pump, pipeline, wing, hydraulic tank and radiator. By comparing with some aircraft flight data, it is proved that the simplified thermal simulation method can simulate the thermal characteristics correctly with a reasonable margin of error, which is significant for analyzing the thermal characteristics of aircraft hydraulic system.