The Development And Some Applications Of Ship Performance Numerical Tank

Traditionally, tests of ship hydrodynamic performance depend on physical tank. Model tests in physical tank are not only time-consuming but also strenuous. Its results are easily affected by testing instruments. Along with the development of the computer science and numerical technology, numerical simulation becomes a critical technique of studying and solving hydrodynamic problems. Now numerical tank based on CFD theories has become hot research topics in ship and ocean engineering.On the basis of reviewing and summarizing the recent research progress of this subject, ship performance numerical performance tank has been built which is similar to the physical one depending on modern numerical theories and computing methods as well as computer system in order to simulate the interaction between fluid and ship hull. Tests conducted in numerical tank will substitute model tests to some extent. Compared to model test, numerical test not only costs less labor and fees, but also diminishes effects of error due to the facilities of model tank. Numerical tests are not confined by dimensions of models and there are no scale effects. The detailed information of flow around the ship can be obtained using method of simulation which has received extensive attentions.Based on CFD theories, a numerical wave tank of which the fuctions are more perfect is built to suit the ship performance test. The critical technology of numerical wave generating and wave absorbing are discussed and studied furtherly. Based on the platform of Fluent using UDF, various types of wave-generating and absorbing system are developed. The technologies of specific moving mesh including whole domain movement, rigid body movement combined with re-meshing method, rigid body movement combined with interface and multiple reference frame(MRF) have been discussed to suit various types of ship performace test and simulation.On the basis of applications of ship performance numerical tank, this paper has developed a method to evaluate hydrodynamic coefficients of the ship oscillating in waves. The added mass and damping coefficients of various oscillating modes have been calculated and agree well with the corresponding ones of potential theories. Its results indicate that this method, which is helpful for the application and extention of numerical tank, can not only give detailed information of flow and correct hydrodynamic coefficients of the ship but also be easily applied in researches about hydrodynamics of marine floating body. It is a useful supplement of thechnologies of numerical tank.