Simulation on Underwater Salvo Load Characteristics of Multi-Slender Body Vehicles in Single Launching Tube

In respect of the underwater salvo adjacent tube effect caused by dense arrangement of several slender body vehicles in single launching tube, the volume of fluid(VOF) and multiphase flow methods are used to establish a three-dimensional unsteady multiphase flow simulation model for underwater vertical salvo, in which the dynamic grid technology for user-defined function(UDF) to control the motion of two vehicles is adopted and the influence of suspended flange, tube cover and submarine shape on the flow field characteristics of the tube mouth is considered. Then, the load characteristics of adjacent tube watertight head cover and water back-flow hammer are obtained. The influence of first-launched vehicle on the load characteristics of second-launched vehicle is analyzed, and conclusions are drawn as follows: 1) After launching of the first-launched vehicle, the flow field at the tube mouth tends to stabilize quickly, and the load of watertight head cover of the adjacent tube is slightly smaller than that of the first-launched vehicle but with similar law when the second vehicle is launched. That is, the flow field at the tube mouth of single tube has little effect on the salvo interval; 2) After launching, the flow field of launcher tends to stabilize quickly both inside and outside, and the amount of seawater poured back into the launcher is relatively small, which may affect the steering performance of the submarine; 3) Second-launched vehicle has great influence on the characteristics of water hammer load and flow field of first-launched vehicle in launching tube. This research may provide a reference for dense arrangement scheme demonstration of underwater multi-slender vehicle and safety analysis of salvo.