Research Of The Counter-rotating Turbine Power System For Torpedos

For a heavy torpedo with a diameter of 533 mm to operating at 70 knots,the engine output power has to be larger than 1000 k W.The gas turbine is the most feasible option in future.The long duration flight provides the demand to the torque speed and the system economics.With its own oxidant,the turbine engine utilizes the partial supersonic impulse turbine.The power system has the following features:(1)turbine performance is limited by the structure material.The speed ratio of the turbine is far away from the optimal one,resulting high loss and low system efficiency;(2)the single-axis output of the traditional power system requires the power from the turbine to enable the operation of the auxiliary system.The auxiliary power consumption accounts for more than 10% of the power consumption of the turbine.This paper proposes a new power system,namely,counter-rotating turbine.The configuration consists of the main and auxiliary counter rotating twin screw power output.The auxiliary turbine utilizes the exit energy from the main turbine to power the auxiliary components.This increase the whole system efficiency more than 10%.The result is a compact system configuration.This paper studies several key issues of the new power system.The main research work and innovation points are as follows:(1)The feasibility of this new power system including the mathematical modeling and performance prediction of the traditional and new torpedo turbine engine power system,and the determination of the steady-state operation condition of turbo are investigated.The auxiliary system under a variety of conditions is investigated.This confirms the power output from the auxiliary turbine is high enough to cover the requirement from the auxiliary system.This work provides the theoretical insight into the configuration of new power system.(2)The configuration layout of the new turbine power system is discussed.Compared with the traditional engine with a single output shaft,this new power system not only requires the propellant flow to control the main turbine,but also the auxiliary turbine has to be controlled.The proposed strategy is to control the rotational speed of auxiliary shaft system by adjusting the absorption power of auxiliary engine.Using MIMO system,the mathematical simulation results show that the two shafts of both main and secondary levels can be well coordinated under controlled conditions and meet the requirements of various working conditions of torpedo.(3)The launching strategy during the start-up process of the new turbine engine power system is studied.Because of the local positive feedback characteristics of turbine engine power system,the start-up of turbine engine system is a key technology.Due to the strong coupling and dynamic response speed of the two shafts,the reliable start-up is a decisive factor in the feasibility of the new power system.The open-loop response characteristics of the new power system,the main level of the shaft and auxiliary shaft system are all considered.The mathematical simulation verifies the feasibility of launch strategy.The work focuses on the key problems of the power system and demonstrates the feasibility of the new turbine engine power system.