Research On Numerical Simulation Of A Free Surface Transport

In this work, an overview of free surface simulation method was firstly given and the detailed description and comparison of some typical methods were carried out. Finally, VOF method was chosen to simulate free face after the advantages and disadvantages of each method were taken into consideration. In the VOF method, there are a variety of specific implementing measures. A new style was developed in this study based on the improvement of YOUNS method and oblique line method in the VOF method was selected to simulate free face.Solving the amount of liquid transport between grids is the key to the simulation of free surface and VOF method is to solve the transport volume of liquid between the grids. Basic steps for the simulation of free surface were described as follows: According to the initial given liquid distribution, the improved normal formula was put into use to solve the normal of free surface at the initial time with the combination of the properties of oblique lines, and points of intersection between oblique lines and free surface mesh boundaries were simulated. There are two intersection points between oblique line and each boundary of free face after the intersection of simulated oblique line and free face grid boundary. Then the fitting of the two intersections was carried out and the simulation of free surface at the initial time was completed. According to the fitted free surface combined with the flow field, the amount of liquid transport of the next time period was calculated, and then the liquid content of each table cell at the next time was solved. In the end, the free surface of next period was simulated. The process mentioned above can be used to simulate the existence forms of free surface at any time.Various analog results of free surface at the given speed were conducted and analyzed. Its volume change rate lies between 10-8 and its shape does not fluctuate sharply. Also, the SIMPLE algorithm was employed to calculate the flow field of dam break and its free surface was simulated and its numerical results were compared with those of STANSBY. Both of them have remarkable similarities. A novel method was proposed to simulate free surface in the study and this will provide some references for the fields involving industrial production, mechanical design, and so on.