I want to specify the gradient of the surface tension with respect to the temperature at a liquid free surface boundary, the Marangoni Stress for the its Shear Condition should be specified? How to add Marangoni Stress for a free liquid surface¡¯s Shear Condition?

Thanks in advance.

Dear wanghong , I thinck you can add marrangoni tension at the free surface in VOF model .

If you want to include the effects of surface tension along the interface between one or more pairs of phases, as described in Section 20.2.8, click Interaction... to open the Phase Interaction panel

1.Turn on the Surface Tension option.

2. If you want to include wall adhesion, turn on the Wall Adhesion option. (When Wall Adhesion is enabled, you will need to specify the contact angle at each wall as a boundary condition (as described in Section 20.6.14.)

3. For each pair of phases between which you want to include the effects of surface tension, specify a constant surface tension coefficient. All surface tension coefficients are equal to 0 by default, representing no surface tension effects along the interface between the two phases

but do you want to give constant value of marangoni shear stress or depandant with temperature ???