Experimental Investigation Into The Effects Of Fluid-structure Interaction On The Sloshing Waves In 3D Tanks

Many engineering practices in the field of aviation.aerospace, marine engineering and energy chemical engineering involve liquid sloshing problems, such as tankers driving on the road, ships sailing in liquid cargo, the oil storage system of floating offshore and the liquid storage systems of flying liquid rocket propellant tank when they are excited by outer loads.the liquid will produce a sharp movement, and have a strong impact on local tank walls, cause the local destruction of structure. and the elastic deformation of the bulkhead structure has a certain influence on the hydrodynamic characteristics of liquid sloshing. Study on liquid sloshing problems has important scientific significance and application value.In this paper, the main work is through the physical model experiment, the liquid sloshing problem of rigid and elastic cubic tanks under simple harmonic excitation is studied. In the experiment, we analyzed two kinds of fluid wave elevation change under the different liquid depth, different excitation amplitude and excitation frequency. We measured the resonance frequencies of the two kinds of tank under the different conditions of liquid depth. And we mapped two tank of frequency-wave elevation figure under the shallow liquid depth. And the experiment data of rigid and elastic tanks was compared, we analyzed wave elevation change regularity and distinction of two kinds of tank.Main work content is as follows:In the shallow deep fluid conditions.the depth of the water tank width ratio of h/L is 0.167, the experiment gives the elastic and rigid tank vibration value of first-order natural frequency, both are close, and about 5% larger than linear theoretical value. Respectively with rigid and elastic tank under the simple harmonic longitudinal vibration in different frequency of wave shape are classified and analyzed in the two-dimensional wave, transition state and three-dimensional resonance and the second order resonance fluid compartment when different wave forms, such as the wave height distribution and change characteristics of liquid sloshing, wave high frequency response curve and spectrum analysis results are given.Comparative analysis results show that:under the same excitation, when the liquid hold liquid level 2 d present undulation, the wave height of the liquid of the elastic and rigid tank hold basically the same. When liquid in the liquid level is in a state of three-dimensional wave, the wave height of elastic tank is bigger than the wave height of the rigid tank in the situation, in the first order resonance case, angle point# 1 of the elastic tank average wave height is about 20% larger than rigid tank’s.In the deep fluid conditions, the depth of the water tank width ratio of h/L=0.333, the experiment gives the elastic and rigid tank vibration value of first-order natural frequency, both are close, and about 2% smaller than linear theoretical value. Respectively with rigid and elastic tank under the simple harmonic longitudinal vibration in different frequency of wave shape are classified and analyzed in the two-dimensional wave, transition state and three-dimensional resonance and the second order resonance fluid compartment when different wave forms, such as the wave height distribution and change characteristics of liquid sloshing, wave high frequency response curve and spectrum analysis results are given.Comparative analysis results show that:under the same excitation, when the tank is in a state of sub-resonance, the wave elevations of four Angle measuring point and the center point in rigid tank are large, but the wave elevations of the center of four edges in elastic tank are large. In the other state, the liquid sloshing mode of the elastic and rigid tank is almost the same, and the liquid elevations are close.