Discussion Forum

Hello All,

I'm new to COMSOL, and I am doing a simulation in which I have a droplet modeled as a rigid body on an truck radiator fin (aluminum) surface. The ultimate goal of the study is to study the evaporative cooling. The main purpose of this initial analysis was just to have a visual of the droplet displacement (in the Video Player). Given the input forces and the equation of motion I have derived and put in all the appropriate prescribed displacements as functions of time.

So when I allow the Player to run, or go through the frames, the motion of the droplet seems correct (as per the prescribed displacements). However, no matter what time range I utilize, whether it's range(0,0.04,10), range(0,0.04,20) or range(0,0.04,100) the video that the Player generates always shows the same displacement (same end point at the end of the respective time ranges). Is there something I'm doing wrong with this?

Note/Optional: This is all done in the Structural Mechanics: Solid Mechanics module since that is what I have available. Initially I put in the appropriate forces, Weight - (Steady State, since not taking into account droplet evaporation yet), Drag Force - (Steady State, since not taking into account change in droplet shape as it evaporates or the relative velocity of the droplet), and Adhesion Forces (I made this a function of droplet velocity). However, when I ran the study with these forces, the displacements it showed over time were very strange in the Video Player (it would move back and forth). Any thoughts on that issue? Also, just thought I'd mention, before I did prescribed displacement I made the droplet contact surface and the radiator fin an identity pair, changed it to contact pair later.

Thanks & Regards,
Chaitanya