Analysis of Forces and Stability in Submerged Land Vehicle During Deep Fording Operations

Abstract

An amphibious vehicle floats on the water surface and its mobility is not limited by the depth of water body. For most submerged land vehicle (SLV) application, several water-based operations are limited to fording. This being a nascent field the behavior of the submerged land vehicle during deep fording is still not much publicized. Hence during deep fording, the dynamic forces that act on the SLV are unknown. These forces directly influence and affect the stability of the SLV under water. Therefore, there is a need to analyze the flow around the SLV. However, since SLV development is quite expensive, the overall manufacturing of the vehicle prototypes is also restricted to avoid large expenditure. Conduct of experimental flow simulation on a dedicated full scale prototype is not viable in design finalisation phase. Hence, the situation demands for conduct of studies using less expensive scale model testing and computer simulations that offers optimum solution alongwith with the freedom of multiple test conditions. The research aims at examining the existing SLV with regards to its amphibious attributes. From the inferred external flow using CFD analysis, which is the standardized approach applied for determining object s characteristics under the influence of continuous non-static fluids, behavior of the SLV in submerged conditions can be evaluated. The analysis facilitates in determining the simulation pattern governing the SLV s movement through water. It also evaluates the dynamic stability of the SLV by determining the relationship between the impact of fluid flow on the vehicle s motion and whether it is affected by the different involved parameters or not. Considering the present aspect, as the SLV moves under water, the fluid is not confined between wall type conditions such as pipes or confined flow cases. Fluid remains free to flow around the SLV and it only interacts with external or otherwise wet part of the SLV.