A technique using numerical methods and algorithms to solve and analyze problems that involves fluid flows. CFD analysis has come to be widely used over the whole range of design from aircraft conception to improving efficiency of water turbines, from the gas dynamics of internal combustion engines to interaction between the hulls of ships and their propellers. A great range of propeller design problems such as propeller-induced hull pressures, character of cavitation, etc, are becoming possible to be solved by CFD methods.