【摘要】 为了深入理解热毛细对流不稳定性的特征,数值模拟了内环壁加热、外环壁被冷却的硅油环形浅液池内热毛细对流.发现在内外壁间温差相同的情况下,在内壁加热的液层里,流体表面的温度梯度高于外壁加热情况下10%左右;相应地,发生热流体波的临界Marangoni数Ma_c=3.06×10~5(或临界温差ΔT_c=4.58K)低于外壁加热情况下的Ma_c=3.34×10~5(或ΔT_c=5.0K).超过临界条件后,内壁加热液池内形成振荡的多涡胞热流体波,它由共存的两组波数相同、频率和振幅相同、沿周向传播方向相反、沿径向凹向高温壁传播的、弯曲螺旋状的热流体波组成,并相互干涉形成点状波纹.更多还原

【Abstract】 In order to investigate the characteristics of thermocapillary flow instability,thermocapillary convection is investigated with three-dimensional numerical simulation in a shallow annular pool (depth d= 1 mm) of silicone oil (0.65 cSt,Pr=6.7) with the heated inner wall and the cooled outer wall.The numerical results show that,surface temperature gradient in the pool heated from inner wall is 10% higher than that heated from outer wall with a fixed temperature difference between the outer and inner walls.Meanwhile,the critical Marangoni number for the incipience of hydrothermal wave (Ma_c=3.06×10~5) in the pool heated from inner wall is smaller than that (Ma_c=3.34×10~5) heated from outer wall.Furthermore,numerical results indicate the oscillatory multicellular wave in the pool heated from inner wall when Ma exceeds Ma_c. The oscillatory multicellular wave is composed of two hydrothermal waves propagating in opposite azimuthal directions,which are interfered each other to be dot ripple.更多还原