Study on the impulsive pressure of tank oscillating by force towards multiple degrees of freedom

Abstract

Impulsive loads should be excited under nonlinear phenomena with free surface fluctuating severely such as sloshing and slamming. Estimating impulsive loads properly are important to recent numerical simulations. But it is still difficult to rely on the results of simulations perfectly because of the nonlinearity of the phenomena. In order to develop the algorithm of numerical simulations experimental results of nonlinear phenomena are needed. In this study an apparatus which can oscillate a tank by force was introduced in order to investigate impulsive pressure on the wall of the tank. This apparatus can oscillate it simultaneously towards 3 degrees of freedom with each phase differences. The impulsive pressure under the various combinations of oscillation direction was examined and the specific phase differences to appear the largest peak values of pressure were identified. Experimental results were verified through FFT analysis and statistical methods.

Sloshing simulation of a tank oscillating towards multiple degrees of freedom by particle method

“…Here v is the speed of particles, p is the pressure of particles,  is the density of fluid, K is outer forces and  is the kinematic coefficient of viscocity of fluid. From Gauss's theorem equations (1) and 2are transformed into flow equations of integral shape.…”

“…In previous study [1] we chose 3 pairs of 2 degrees of freedom from 3 ones. Those will be subscribed as follows ( X,  Z, X Z ).…”

“…4 (d) show comparison of the experiment and simulation results for time history of pressure value at the position where the pressure sensor is attached. The experimental values are results obtained through a 100Hz low-pass filter and the accuracy of those results are evaluated by a FFT analysis and statistical approaches in the previous paper [1].…”

“…In the previous study [1] an apparatus which can oscillate a tank by force was introduced in order to investigate impulsive pressure on the wall of the tank. This apparatus can oscillate it simultaneously towards 3 degrees of freedom (up-down, left-right and rotation) with each phase differences.…”

Study on incompressible fluid analysis by three-dimensional particle method with finite volume techniques

“…In order to avoid these problems, the authors have proposed another particle method based on the finite volume techniques. The usefulness of the proposed method in two-dimensional problems has been verified by comparing the pressure fluctuation when a water tank of the two-dimensional model is forcibly oscillated with the corresponding experiment [1]. Therefore, in this research, the authors extended the algorithm so that the calculation formula can be applied to three-dimensional problems.…”