CAJ | 학술논문

建立了溴化锂溶液沿平板降膜的流动模型.利用 VOF 方法捕捉降液膜的自由流动表面,利用 CSF 模型考虑表面张力对降液膜流动的作用,研究了入口扰动频率、降膜 Re 和平板倾斜角对降膜波动演化过程的影响.模拟结果表明,入口处的低频率扰动发展为孤波,随着频率的增加,波长减小,孤波与孤波通过他们之间的波后、衬底和毛细波相互影响,而高频率扰动演变成毛细波.随着Re 的增加,波幅和波长增加,同时波峰处的循环流动强度增加.随着倾斜角的增加,重力沿流动方向的分力增加,波发展速度增加.同时分析了波内的速度场和壁面切应力等动力学特性.
건립료추화리용액연평판강막적류동모형.이용 VOF 방법포착강액막적자유류동표면,이용 CSF 모형고필표면장력대강액막류동적작용,연구료입구우동빈솔、강막 Re 화평판경사각대강막파동연화과정적영향.모의결과표명,입구처적저빈솔우동발전위고파,수착빈솔적증가,파장감소,고파여고파통과타문지간적파후、츤저화모세파상호영향,이고빈솔우동연변성모세파.수착Re 적증가,파폭화파장증가,동시파봉처적순배류동강도증가.수착경사각적증가,중력연류동방향적분력증가,파발전속도증가.동시분석료파내적속도장화벽면절응력등동역학특성.
Using aqueous LiBr solution as flowing fluid, the numerical simulation about wave evolution and flow dynamics of falling film along a wall was carried out. Volume of Fluid (VOF) model was used to track the free surface of the falling film and the Continuum Surface Force (CSF) model was used to consider the effect of the surface tension of the fluid on the dynamic boundary conditions of the falling film. The simulation results show that the small disturbance with low frequency at the flow inlet may give rise to a solitary roll wave with large amplitude and some small amplitude capillary waves in front of it. When the disturbing frequency at the flow inlet is increased, the solitary waves become closer, and via the wave tail and capillary waves between them, the solitary waves interact on each other; and when the disturbing frequency is high, the wave amplitude becomes smaller and the accompanying capillary waves disappear. Furthermore, as the Reynolds number of the flow is increased, the wave amplitude, wave length and the intensity of recirculation in the ridge of the wave increase; and as the inclined angle of the wall is increased, the component of the gravity parallel to the wall increases, thus the wave grows more quickly. Moreover, in this work, the velocity vectors in the wave and the shear stress on the wall surface were investigated.