Static Contact Angle (fluids)

[member 428835]

Hi PF!

I have an experiment where a wedge about 160mm long is in microgravity. I withdraw silicone oil from the wedge at a relatively slow rate (no turbulence). Since the wedge angle is small, a lubrication approximation is made. Inertia is shown to be low.

I want to simulate this flow. When considering a contact angle model to employ, I implement a constant contact angle model equal to the static contact angle, 0 degrees. How do I know if this is valid, or if a dynamic model should be implemented?

 

[Achy47]

Hello,

Thank you for sharing your experiment and question with us. It sounds like you are conducting an interesting study on fluid dynamics in microgravity.

When deciding on a contact angle model to use in your simulation, there are a few factors you should consider. First, you should make sure that the contact angle model you choose is appropriate for the type of fluid you are working with. For example, some models may be more suitable for Newtonian fluids while others may be better for non-Newtonian fluids.

Secondly, you should consider the conditions of your experiment and whether a static or dynamic contact angle model would be more appropriate. Since you mention that your experiment involves slow withdrawal and low inertia, a static contact angle model may be suitable. This model assumes that the contact angle between the fluid and solid surface remains constant throughout the experiment.

However, if you think that there may be variations in the contact angle due to changes in flow rate or other factors, a dynamic contact angle model may be more accurate. This model takes into account the change in contact angle over time.

In order to determine which model is most valid for your experiment, it may be helpful to compare the results from both models and see which one better matches your experimental data. Additionally, you could also consult with other experts in the field or conduct further research on similar experiments to see which contact angle models have been used in the past.

I hope this helps guide your decision on which contact angle model to use in your simulation. Best of luck with your experiment!