Estimation Method of Nozzle Exit Speed for Torpedo Turbine Engine

Open loop cycle underwater engine system is more sensitive to variable working condition than a piston engine system. In order to maintain the efficiency of the turbine engine system, higher nozzle efficiency is necessary. In this paper, by analyzing the working characteristics of an open loop cycle turbine engine system in a multi-speed torpedo, the parameters relationship is obtained, and the nozzle working characteristics in non-designed working condition is determined. According to the theories of thermodynamics and aerodynamics, the flow behavior when the gas passes the pressure wave at the nozzle exit section is analyzed, and an estimation method of the exit speed of a supersonic nozzle in an underwater turbine engine system is presented concerning the changes of gas speed and the direction. This method may be applicable to the turbine engine system optimization design and system modeling.