The Research Of Prismatic Liquid Tank Sloshing Based On Partial Cell Parameter Youngs Method

With the development of the large liquid cargo ship, the problem of liquid tank sloshing has become prominent. To improve precision and numerical stability, a better method is proposed to calculate the sloshing load of the cargo cabin with non-rectangle boundary. The method is based on VOF method, adapting Yonngs methods to reconstruct the free surface, combined with the concept of Partial Cell Parameter. Double-median-mean-limited filter method is used to smooth the sloshing load-time curve and the design sloshing load which is practical for enginering is obtained. The sloshing load of some LNG ship is predicted basing on the method and the structure strength analysis of the pump tower is carried out. The main work of this paper includes:1) Based on volume of fluid (VOF) method, the Youngs method is applied for free surface reconstruction. In addition, the Partial Cell Parameter processing is introduced, which is used to deal with complex non-rectangular cabin boundary. The calculation result of this method is compared with that of the traditional VOF method and experimental data.2) In order to avoid numerical disturbance that may occur during the calculation, double-median-mean-limited filter method is applied to smooth the sloshing load-history curve and a relatively convincing sloshing load is obtained.3) Based on the numerical calculation method in this thesis and filtering algorithm for sloshing load, together with Morison equation, the sloshing load of the pump tower of a LNG vessel is predicted and structure strength analysis for the pump tower is carried out.