Stability and Drag Analysis of Wheeled Amphibious Vehicle Using CFD and Model Testing Techniques

Amphibious design of combat vehicle has become a challenging task in the context of increase in Gross Vehicle weight (GVW) of present generation combat vehicles due to demand for high protection levels and higher capacity engine and transmission, incorporation of multiple weapon systems, increased ammunition storage and larger addition of electrical and electronic items. Development of combat vehicles is complex and very expensive, and normally limited with less number of prototypes. The scale modeling and CFD analysis offers a viable solution to accomplish the amphibian design of a combat vehicle with adequate confidence before manufacturing the actual prototype. In the present work, an approach involving experimental towing test using scaled model and CFD simulation has been used to carry out the amphibious design of an 8X8, wheeled, combat vehicle with GVW of 22 ton. In this work, a 1/5th scaled model of the vehicle was manufactured and tested in the towing tank at different test speeds for drag and stability analysis. CFD analysis was carried out on the full scale model to gain adequate details about the dynamics of vehicle in the water in addition to drag estimation. Good correlation has been found in drag values and the flow patterns obtained from towing tank tests and CFD simulations.