[Hebra007]

Hello everyone,

I am working on a simulation involving a cylinder in a channel, where half of the channel is filled with stagnant water and the cylinder moves directly beneath the water surface. Figure 1, which I have attached, illustrates the general concept of this problem.

Initially, to simplify the problem, I assigned a fixed speed to the cylinder, which yielded satisfactory results. It's worth mentioning that I utilized an overset mesh for the cylinder and opted for the laminar flow option in my simulation.

Now, my goal is to set an initial speed for the cylinder and allow it to come to a stop due to drag force. I understand that this requires writing a User-Defined Function (UDF), and with assistance from a friend, I have drafted something. However, it's not functioning as intended – the cylinder isn't moving.

All the tutorial videos I've found online focus on scenarios where there's a moving flow over a stationary object, or they involve defining a path for an object to study its impact on stagnant fluid. Unfortunately, I haven't been able to find any resources that directly relate to the specific requirements of my simulation which specifying a initial velocity and see how the media affect that.

I wanted to attach the archive file but the volume was 330 MB and it was not possible but I have attached of my UDF code.

It is a great help if somebody can help me with this issue or send me a link of some related video or text which helpful.

appreciate your time.