航空瞬变电磁探测系统共中心式吊挂结构气动力学建模仿真与设计

Helicopter-Borne Transient Electromagnetic (HTEM) method is an important means for efficient exploration in complex terrain areas. Reasonable design of the towed structure to maintain aerodynamic dynamic balance during flight is key to ensuring safe operation and stable measurement. Since the balance of the towed structure is susceptible to changes in complex flight conditions such as altitude and airspeed, and the scale difference between the towed bird and cable makes integrated modeling challenging, the aerodynamic model of the towed structure is highly complex, making its simulation design a major difficulty in airborne electromagnetic system development. This paper employs the Reynolds-averaged Navier-Stokes (RANS) method and turbulence models to simulate the towed bird, while the crossflow law is applied to model the cable, achieving integrated modeling of the entire towed structure. Based on force equilibrium conditions and geometric constraints of the bird′s attitude, an optimized design of the towed structure is realized. Taking a flight altitude of 100 m and an airspeed of 90 km·h⁻¹ as an example, the towed structure parameters were designed through simulation and applied in an HTEM flight test in Jingzhou, Hubei Province. The results demonstrate stable operation of the towed structure, with the bird′s pitch angle fluctuation controlled within 0 ± 2.5°, meeting the requirements for safe flight and stable measurement. This validates the effectiveness of the proposed method and design parameters, providing a scientific approach for the towed structure design of airborne transient electromagnetic systems.