幂律流体Wilhelmy吊片法动态湿润的理论与实验研究

Theoretical and Experimental Study on Dynamic Wetting of Power Law Fluid Under Wilhelmy Plate Method

幂律流体的黏度由于会随着剪切应变的变化而变化,其动态湿润机理比牛顿流体更加复杂。本文通过简化的二维吊片法模型,采用楔形区假设和黏性耗散理论建立了适用于幂律流体中剪切稀化流体吊片法湿润的表面张力驱动力和黏性滞动力动态平衡条件下的理论公式,并进行实验.通过对比,发现二维吊片法的理论公式与实验数据符合良好,并计算出楔形区截断长度的大致量级;分析了圆形三相接触线下该公式适用性较差的原因,定性解释了三相接触线形状对幂律型非牛顿流体湿润的影响.

Since the viscosity of the power law fluid varies with the shear strain, its mechanism of dynamic wetting is more complex than the Newtonian fluid. By using wedge region hypothesis and viscous dissipation theory under the simplified two-dimensional model, the theoretical formula was established for shear thinning fluids of power law fluid in Wilheliny plate wetting which driving force and braking force dynamic reach the equilibrium condition. The corresponding experiment was conducted, it was found that the theoretical formula was in good agreement with the experimental data, and the approximate magnitude of truncated length was calculated. Meanwhile, the reason for the poor applicability of the formula under the circular contact line is analyzed, and the influence of the shape of three phase contact line on the wetting of power law fluid is qualitatively explained.