Research On The Helicopter’s Fuel Tank Crashworthiness Based On The Fluid-solid Coupling

Along with circumstances that the countermeasure is more and more intense andbattlefield environment is harsher in the modern war, the helicopter’s survivability isfacing serious challenge. Considering this situation, how to improve the safety factorof aircrew is an urgent issue to military forces around the world. For the intrinsic rotorwing, special combat mode and unique military purpose, the helicopter’ crashaccidents have a high frequency. To improve the aircrew’s safety, the concept ofcrashworthiness is proposed. As the important part in it, the fuel system’scrashworthiness attracts many scholars’ attention. Based on the fluid-solid couplingtheory, this paper simulated and analyzed the certain type of helicopter’scrashworthiness under certain circumstances and provided the theoretical guidance forthe helicopter development.The main contents in this paper are as follows:(1) Reviewing the necessity and urgency for the crashworthiness，summarizingthe theoretical knowledge and progress for the fluid-solid coupling theory, and theresearch status for the simulation technology of the crashworthiness.(2) Describing the definition of the fluid-solid coupling theory, and introducingseveral typical numerical algorithms, including the lagrangian method, eulerianmethod and ALE. Besides that, analyzing the characteristics of several algorithms,and introducing the basic equation and realization for ALE.(3) Summarizing the classification and characteristics of the fuel tank. Analyzingthe structure and characteristics of the soft tank. On the basis of MSC.Dytran,simulating the process of the bare tank fall speed vertical impact the ground by17.3m/s using ALE algorithm. Analyzing the performance for crashworthiness of the baretank filled with water.(4) Summarizing the structure form of exact helicopter fuel tank with oil holeand protective equipment. Considering the exact fuel tank, using the ALE algorithmsimulated the crashworthiness performance under the same conditions with adding theprotective frame to that improved the crashworthiness.