液体非线性晃动实验与数值模拟

Nonlinear Liquid Sloshing Experiment and Numerical Simulation

本文对圆柱容器中液体非线性晃动进行了实验测试,利用粒子图像测速(Particle Image Velocimetry,PIV)技术检测了腔内液体流动状态,定量表征了速度场和涡量场随时间的变化,揭示了腔内的复杂流动结构,获得了液面的非线性晃动特征,发现了波形破碎、液滴飞溅同激励频率的相关性。通过对竖直激励晃动的数值模拟与分析,得到液体运动的液面位置,取得了与实验结果相符的计算结果。应用Fluent软件对液体晃动瞬态过程和特征进行数值模拟研究,开展了大攻角的俯仰晃动数值计算,结果表明,俯仰晃动的频率越大,腔体受力越大。本文为充液飞行器飞行控制和总体设计提供了理论依据和优化方法。

Experimental tests were conducted on the nonlinear sloshing of liquid in cylindrical containers.Particle image velocimetry(PIV)technology was used to measure the flow of liquid inside the cavity.The development of the velocity field and the vorticity field were characterized quantitatively.The complex flow structure and the characteristics of the nonlinear sloshing of the liquid surface were obtained.The correlations between waveform fragmentation and droplet splashing with excitation frequency were acquired.Numerical simulation and analysis of the vertical excitation oscillation were carried out.The positions of the liquid surface in motion were obtained numerically,which were consistent with the experimental results.Then,the transient process and characteristics of liquid sloshing were numerically simulated using Fluent software,and numerical calculations of pitch sloshing at large angles of attack were performed.The numerical results showed that the force acting on the cavity rose with the frequency of pitch sloshing.This research provided theoretical basis and optimization design methods for the flight control and overall design of liquid filled aircraft.