3D Simulation Of Viscosity Flow In Intake Of Waterjet Propulsion

Since Tuguda and Hasi invent the equipment of waterjet, up to now, it has been 354 years and its history is the same longer as screw propeller. But because some of key technologies, such as pipe system with lower loss and no vacuole, pump with high efficiency and big capability, the good combination among ship, equipment and pump, navigation sets with good hydrodynamic performance, have not been settled, the evolution of waterjet is slower. The goal of this paper is to advice for manufacturing inlet pipe system with low loss and no vacuole.Adding modern communication technology to traditional design is modern production design trend. In this paper, in virtue of CFD technology, there is a method being found to enhance the system efficiency of waterjet, to ameliorate the design method, to reduce thedesign cost. Furthermore, this paper apply CFD software-FLUENTto simulate the flow of the water in waterjet inlet, achieved many flow details, flow law and performance parameter. In addition, there are many simulations to compare the factors that can affect waterjet system efficiency, such as mostly geometry parameters,IVR and the sucking of boundary flow. Based on a great deal of computation, the factors that affect the waterjet inlet performance and the degree of affections were gained. On the basis of analysizing the compute results, the better geometry parameters, IVR and other factors to enhance the system efficiency of waterjet were obtained, and this research provides many basis data for waterjet inlet design.Firstly, this paper introduces how to set up a model, how to use FLUENT, how to deal with fluctuating phase in viscosity flow and how to confirm the simulation methods. Then, two shapes of inlet pipe were simulated with 582 situations. And after compared with predecessors'researchers and confirming the simulation method, 64 models were choosed. Based on the detailed analysis on these simulation results, as follows can be concluded:1. IVR is a key factor affecting the fluid field in inlet pipe. Usually, if IVR is about 1.0, the efficiency of inlet pipe is best. So, when it is designed, we should do our best to make IVR smaller than 1.0.2. The fluid field in fore of impeller is regularized than the place of siphon. So a straight part should be designed in fore of impeller so that the irregular can be weaken.3. On the condition of no influence on other performances, smaller angle of ramp is better. It is best that the gradient between the start point of ramp and the bottom of ship is zero. In addition, in order to pretend rip current, we should do our best to make the curvature is consecutive.4. It is complexity that the sucking of boundary flow affect fluid filed. It makes the pressure higher at the ramp and lower at the lip. And its effects are different in the inlet pipes with various shape...