Modeling method of liquid sloshing in microgravity environment of spherical tank

Abstract

The invention provides a modeling method of liquid sloshing in a microgravity environment of a spherical tank. Firstly, an equivalent mechanical model of liquid sloshing under the microgravity environment of a spherical tank is established. The equivalent mechanical model is a three-axis spring-mass equivalent mechanical model which contains the rest mass m0 and the sloshing mass ms, wherein the rest mass m0 is located in the center of the spherical tank, the sloshing mass is connected with the tank by three spring dampers with a stiffness coefficient of Ks and a damping coefficient of Cs. When the sloshing mass is in the equilibrium position, the directions of the three spring dampers are respectively overlapped with the three axes of the spherical tank. Then, the n-order natural frequency [omega]0i and the modal [phi]i of the liquid sloshing in the zero-gravity environment of the spherical tank are calculated. Finally, based on the force of the liquid applied to the wall of the tank and the kinetic energy of the sloshing liquid relative to the tank, the force of the equivalent mechanical model and the kinetic energy equivalent principle, the sloshing mass ms and the rest mass m0 of the equivalent mechanical model are obtained by calculation.

Description

technical field [0001] The invention is applied in the field of liquid sloshing analysis of liquid-filled spacecraft, and specifically relates to a modeling method for liquid sloshing in a spherical storage tank in a microgravity environment. Background technique [0002] According to the overload conditions of the spacecraft during flight, the movement of the fluid in the storage tank can be divided into several working conditions: weightlessness, micro-gravity, low-weight, normal weight and overweight. and slow rotation conditions, etc. For liquid-filled spacecraft, the main research is on the fluid motion characteristics of weightlessness or microgravity and low-gravity and spin conditions. Theory and practice show that when the Bond number ( Where ρ is the density of the liquid; g is the overload acceleration; L 0 is the characteristic length, generally taken as the radius of the free liquid surface; when σ is the surface tension coefficient) is 0, it can be regarded...

AI Technical Summary

Problems solved by technology

The spacecraft has a high positioning accuracy. During the attitude maneuvering and stabilization process, the spacecraft tank is faced with a microgravity environment, and the surface tension of the propellant in the tank begins to appear, which may lead to complex sloshing of the propellant in the tank. characteristics, which have an impact on the high-precision attitude control of the platform

The existing small linear shaking modeling methods can no longer meet the needs of its dynamic characteristics prediction

[0005] The problem of small liquid sloshing in a microgravity environment is basically solved by commercial software based on computational fluid dynamics, and the time domain curves of force and moment are obtained. However, it is difficult to directly apply this method to the control system design, and the solution efficiency is low on the other hand. , the solution takes a long time, and it is difficult to meet the engineering needs

Images