横摇-横荡复合激励下液舱晃荡的压力特性

Pressure Characteristics of Liquid Tank Sloshing Under Roll-Sway Compound Excitation

【目的】探究横摇-横荡复合激励下液舱晃荡特点。【方法】基于VOF法的多相流模型对横摇-横荡复合激励下二维矩形液舱晃荡进行分析。【结果与结论】横摇频率(f_(r))与横荡频率(f_(s))不相等且都接近共振频率时,液舱呈现剧烈与缓和相互变化的晃荡特点。当两个外激励频率相等时,每个运动周期内的压力载荷变化稳定。当横荡频率远离一阶共振频率时,f_(r)对应的压力幅值远大于f_(s)、|f_(r)–f_(s)|、f_(r)+f_(s)、2f_(r)+f_(s)对应的压力幅值;当横荡频率接近一阶共振频率时,fr对应的压力幅值逐渐降低,其余频率的压力幅值逐渐增大。

【Objective】To explore the characteristics of liquid tank sloshing under roll-sway compound excitation.【Method】A multiphase flow model based on the VOF method is used to study the two-degree-of-freedom swaying problem of rectangular liquid tank under the compound excitation of roll and sway.【Result and Conclusion】Contrasting the variation characteristics of the sloshing pressure under roll excitation,sway excitation and roll-sway compound excitation,it is found that when the rolling frequency(f_(r))and swaying frequency(f_(s))are not equal and both are close to the resonance frequency,the tank shows the sloshing characteristics of violent and gentle mutual change.When the two external excitation frequencies are equal,the pressure load variation within each motion cycle is stable.FFT analysis of the sloshing pressure time course under compound excitation reveals that when the operating conditions where the transverse frequency is far from the first-order resonant frequency,the pressure amplitude corresponding to fr is much larger than that corresponding to fs,|f_(r)−f_(s)|,f_(r)+f_(s),2f_(r)+f_(s)When the swaying frequency approaches the first-order resonance frequency,the pressure amplitude corresponding to fr gradually decreases and that of the remaining frequencies gradually increases.