The Research Of M-ship's Two-phrase Flow Field Characteristic

M ship was named because of the shape of it's bottom like the letter M,is one of high-performance ship. United States Navy build an M80 warships based on M ship. With a high speed, wave is small, and good maneuverability. Domestic studies about the M-Ship is few.The development of Computational Fluid Dynamics (CFD) provided a reliable and effective method for the Numerical simulation of M-ship's resistance. unseeing numerical simulation to analysis the force that M-ship driving on the free surface, to obtain the drag, lift and information of the flow field. And to verify the accuracy and validity of numerical methods.After tank test, measured model resistance, dip and deep. According to M Ship chart, create a numerical model in the Gambit. Use the commercial software FLUNT to calculate the model, and obtained calculatied data. Analysed and contrasted the data from the numerical simulation and model tank test. In the numerical method, used VOF method to simulate the free surface. Used RNGκ-εto close the RANS equations and solved it.Concluded:1) After try again and again, the numerical methods can simulate the drag and lift of M-ship when Fr▽<3. And have some accuracy. So use FLUENT to simulate M-ship resistance in the still water under lower speed is proved to be feasible.2) After analysed the flow field, air can through the tunnel of M-sip bottom. But the lift of M-ship was caused by the dynamic pressure in the main. In the tunnel, the pressure was small. So little contribution for the M-ship lift. Air was not compressed in the tunnel.3) When Fr▽<1, M-ship was in transition state. Fluent calculation of drag, lift, wave consistent with the experiment, the error rate is very small. The method can also be used for two-phase flow of the drainage-type ship. In particular, the studybulbous, wave and so on. 4) Shallow-water effect have influence on Numerical simulation of M-ship。It embodied in the stern wave form. When speed is 5m/s or 6m/s, and V> 1.2(?).S-wave department is disappeared and there is only scattered wave in the flow field. The Phenomenon is same with model test.5) When Fr▽>3,drag is not accuracy. Ansysied the flow field, when the drag reached peak, there is an air cushion under the model, so the drag became small.The basic esearch on M-Ship would be a reference when study the Numerical simulation about M-ship at high speed...