Effects of uncertainties in the launch parameters on the pressure-equalizing air film around a vertically launched underwater vehicle

Many uncertain factors in the water-emerging process of a vehicle influence the taking effect of the air film around its shoulder in the load reduction and attitude control. Assuming the launch parameters (launch depth, vehicle velocity, and chamber pressure) as sources of uncertainties, the uncertain evolution process of the air film in the water-emerging process of a vehicle is quantified by adopting the nonintrusive polynomial chaos (NIPC) method with the sample space constructed using linearly independent probabilistic collocation points. A sensitivity analysis was conducted for the key performance indicators of the air film to evaluate the contribution of each uncertain launch parameter.