In the paper an efficient numerical algorithm to predict the flow phenomena around the water-jetpropulsion system was described. The potential-based flow analysis method was adopted to predict the velocityand the pressure on the inlet duct of the water-jet propulsion system. The method employed normal dipolesand source distributed on the solid surface such as the inlet duct and the tracked vehicle. The inlet duct andoutlet open boundary surfaces were introduced where the sources and dipoles were distributed to define aclosed boundary surface. The developed numerical algorithm was applied to a tracked vehicle propelled by thewater-jet propulsion system with the different IVR(inlet velocity ratio). The results by the numerical analysiswere compared with the experimental data in order to verify the feasibility of the proposed numericalalgorithm.