Cooling Characteristics Simulation On Combustion Chamber And Engine Housing Of Torpedo Turbine

With the advantages of high energy density,specific power and low vibration noise,HAP tri-propellant(which is made up of fuel OTTO-II,oxidizing agent HAP and coolant sea water)gas turbine power system can greatly improve tactical and technical index of torpedo,such as speed,range and so on.So it becomes one of the most significant development directions towards to the new generation heavyweight torpedo.Combustion chamber and engine are the critical components for a gas turbine power system.For the high pressure(30MPa)and temperature(1300℃)working condition they are suffered,cooling them by the sea water is the only feasible method ensuring them working steadily and preventing them from strength failure.The gas turbine of torpedo is under the stage of functional verification.For the reason that cooling characteristic and regular to the combustion chamber and engine is not mastered,the sea water cooling system is not designed delicately,neither nor the distribution of cooling water and optimization of cooling demand to hot components.So there are a lot of strength failure problem in the experimental process which is led from the pool cooling,making an bad impact on the process of project.So the cooling characteristic and regular towards to the combustion chamber and engine in gas turbine is one of the most critical problems to be solved and studied urgently.In view of the urgent problem above all,the thesis considered the combustion chamber and engine of a gas turbine power system as the research object,carrying out the research of cooling characteristic simulation on combustion chamber and engine shell,studying the delicate structure of cooling flow field and characteristic of thermal transferring by the numerical simulation of thermal-fluid-solid coupling method.Getting the change regular of cooling characteristic and boundary of structural failure under the constraint condition of water flow,water distribution and structure of cooling water,studying the change regular between cooling characteristic of combustion chamber and engine shell with water flow,water distribution and structure of cooling water,provide the basic theory and guidance towards to the efficiency improvement and steady working of torpedo gas turbine power system.Main work of this thesis includes:1)The physicochemical process,such as burning,fluid thermal transfer,solid heat conduction and so on,about the cooling thermal transfer on torpedo combustion chamber and engine was analyzed.Aiming at the physicochemical process,the mathematical models were analyzed and established.The differential governing equations about the mathematical models were obtained,and the simulation methods on the cooling of torpedo combustion chamber and engine were constructed successively.2)Based on the simplified geometric model of combustion chamber and engine,the fluid area which used in numerical simulation was extracted.The mesh generation of numerical simulation area on combustion chamber and engine was completed,and the grid independence verification was carried out.On the basis of relevant literatures,the initial conditions and boundary conditions were determined,and the accuracy of the simulation results was verified.3)Numerical simulation on combustion chamber cooling and thermal transfer was carried out.The results showed that under the existing combustion chamber structure,the strength failure problem might take place when the combustion chamber was under high working condition.Aiming at this problem,the structural improvement scheme was put forward.And the simulation was carried out towards the improved structure.On the basis of above all,the effectiveness of cooling and thermal transfer under the different structures was compared.And the structural improvement scheme was come up.4)The analysis about numerical simulation on engine cooling and thermal transfer was carried out.And strength failure problem also occurred with the existing structural engine,under high working condition.In order to solve the problem,the simulation on two kinds of optimizing scheme were worked out,one of which was aiming at the distribution of cooling water while the other was with a view on structural improvement.And the optimization scheme about cooling water distribution was raised,when there were not strength failure problem occurring in engine.The research above all will provide a valuable support for the structural design about combustion chamber and engine cooling and thermal transfer.