Research on Thermal Network Model for Fast Solution of Temperature Rise Characteristics of Aircraft Wire Harnesses

The design of the Aircraft Electrical Wiring Interconnection System (EWIS) is a core link to ensure the safe and reliable operation of aircraft. As one of the key technologies in EWIS design, the calculation of temperature rise characteristics of aircraft wire harnesses directly affects the safety margin of the system. However, existing calculation methods generally face the bottleneck of difficult balance between speed and accuracy, failing to meet the requirements of efficient and precise engineering applications. This paper conducts an in-depth study on this issue. Firstly, a high-fidelity finite element harness model is established to accurately obtain the convective heat transfer coefficients of wires and harnesses. Based on the analysis of influencing factors of the thermal network model for a single wire, an improved thermal resistance hierarchical wire thermal network model is proposed. A structure of "series thermal resistance within layers and iterative parallel between layers" is proposed to equivalently integrate and iteratively calculate the mutual thermal influence relationship between each layer of the harness, thereby constructing a hierarchical harness thermal network model. This model successfully achieves a significant improvement in calculation speed while effectively ensuring the accuracy of temperature rise results, providing an effective method for high-efficiency and high-precision EWIS design.