| Tank container belongs to the most dangerous third class pressure vessel,Establishing a scientific and rational structural strength design method of tank container to ensure its safe operation has significant engineering value.During the braking process of tanker will produce water hammer phenomena,but till now the relevant design standards doesn’t truly reflect the influence of actual water hammer on the structural strength of the tanker due to the insufficient systematic research on the water hammer generation mechanism.How to calculate accurately the water hammer pressure field of tank container during the braking process and create multi-field coupling mechanism between fluid dynamics and solid finite element analysis is the theoretical premise to establish a scientific and rational design method for tanker structural strength. Based on this, the water hammer generation mechanism during the braking process and the influence law of the material characteristics and process parameters on water hammer pressure were studied, Multi-field coupling mechanism between fluid dynamics and solid finite element analysis was studied and the design method of tanker structural strength based on fluid-structure interaction was proposed, these researches laid a scientific theoretical foundation for the establishment of reasonable tanker design method.The liquid sloshing caused during the braking process is generated by the boundary motion change, it is unreasonable to apply acceleration to the liquid to simulate liquid sloshing process. In order to reflect the liquid sloshing process truly, the Simulation method of liquid sloshing process was proposed by imposing the braking speed boundary condition on the tanker wall.The influence of tanker initial velocity,liquid filling ratio,density,viscosity and anti-wave baffles on the water hammer pressure of tanker during the braking process was studied. The results show that the maximum water hammer pressure is up to2.1MPa which is107times bigger than the maximum initial hydrostatic pressure when the filling rate is0.85and the initial velocity is16.66m/s. Therefore, it is essential to consider the impact of water hammer pressure on the structural strength during the design process.Through the comparative analysis of tanker strength calculated by the traditional engineering experience and the new method based on fluid-structure interaction, the results show that compared with the maximum stress of liquefied gas tank container calculated by the traditional engineering experience, the maximum stress calculated by the hammer pressure in the actual braking process of tank truck can be increased by38.6%.From the safety aspect,the lower limit (0.035MPa) of equivalent pressure of the liquefied gas tanker in JBT4781-2005is unsafe, In order to ensure the tank container safety, the strength design should take the effect of fluid-structure interaction during the braking process into account. |
