Research On Theory And Application Of Torpedo's Water Entry

The torpedo will endure very large force of hydrodynamics at the moment it enters water, so it can't be neglected in design of torpedo that the load of entry causes damages to the structure intensity and inner apparatus of torpedo. It has importart significance for enhancing the reliability of torpedo weapon system in researching on the load of torpedo's impact force at water entry.Velocity pressure is used to calculate the load of entry. And the coupled equation of the interaction between liquid and solid is established, solved in numerical method. At the instant of water entry, the torpedo's head shell suffers pressure of hydrodynamics. Simultaneously, because of the entry of its head, the liquid gives birth to velocity pressure, which will affect the deformation of the torpedo's head shell. It is necessary for forecasting the structure intensity and destruction by overload to calculate and estimate correctly the magnitude and effect of the coupled interaction between liquid and solid.Load is calculated in two different states: water-entry vertically and water-entry slantways in small angles. In order to make sure whether destruction of intensity caused by overload will happen when it enters water from air, the impact pressure of hydrodynamics the torpedo will suffer in the process of entry must be ascertained firstly. The Finite Element Analysis (FEA) Method is used and programmed in Matlab to solve the liquid-solid coupled equation, so that the changes of the load with time at bedewed surface crunodes of the torpedo's head shell can be got.By means of the FEA software: ANSYS/LS-DYNA, the problem of water entry is simulated and analyzed. The process of entry is simulated, and the load at each node on the bedewed surface is computed.It is significative to analyze and calculate the load level of torpedo's water-entry, especially for enhancing the reliability of torpedo and buffer design to limit the load. The thesis puts forward the demand of the buffer component in quality and structure. A principle scheme of buffer shield of torpedo's water-entry is presented too.