Numerical Investigation On Hydrodynamic Characteristic Of Submarine Artesian Cooling System

With the development of the high-speed submarine propulsion technology, the performance of the submarine artesian cooling system has been increasingly required, therefore the optimization design of the submarine artesian cooling system becomes significant for the application and development of the submarine.Based on the basic research scheme about the inlet and outlet parts of the submarine artesian cooling system provided by the relevant departments, a parametric model of the artesian cooling system according to the local submarine structure was first developed in this paper via the surface modeling tools software UG.Then the numerical simulation and theoretical analysis was carried out to study the inner and external flow field of the submarine artesian cooling system using the CFD software Fluent. After that, the multi-objective optimization methods, such as uniform design and genetic algorithm were used to receive the optimum design of the inlet and outlet parts of the submarine artesian cooling system. At last, a set of inlet and outlet parts, including an inlet connecting tube, an inlet deflector shield, an outlet connecting tube and an outlet deflector shield was obtained. The variation of the relative flow velocity and the relative pressure difference was simulated and analysed.The inner and external flow field of the submarine artesian cooling system and its parts was simulated in detail via CFD method. The hydrodynamic characteristics and the resistance characteristics of the major parts of the cooling system, such as the condenser, the valve, the bar and the axial flow pump under different operating conditions were analyzed. The numerical results agree well with the experimental ones.Porous media model is employed to simulate numerically fluid flow in a acondenser. Good agreement is obtained in resistant coefficient of the tube-side between computed results and the experiments,demonstrating the feasibility of the model and the method. It resolved the problem of CFD modeling and the large number of meshes for the condenser. It can be seen clearly the main factors effecting the operation of the condenser from the calculated flow field.The method can be used to simulate the other heat exchangers. The flow behavior in the condenser can provide a theoretical basis for optimal design of artesian cooling system and flow field analysis.The method of separating zones and using the symmetry boundary conditions largely reduce the meshes of the submarine artesian cooling system in the simulation by CFD,the flow characteristics of the flow field outside the submarine body was analyzed under the effects of gravity and boundary layer, which represents the real operating condition of the artesian cooling system. The results show that the artesian cooling system can satisfy the cooling requirement under all the operating conditions. The factors which influence the boundary layer of submarine body were studied, hence the methods of alleviating the boundary layer were proposed.