[vutuankhanh]

https://youtu.be/tbnGK_DYcos?si=7Kn5PpL9zb3xl716
Dear everyone,
This is not a question but a sharing post. I encountered a rather interesting error when simulating in ANSYS Polyflow. My simulation problem is a 1-nozzle jet hitting a flat surface. The fluid used is water. The Reynolds number of the flow is 3,000. The error only occurs when the model mesh is very small.
Error analysis:
- Vortex formation after collision: At Re = 3,000, the flow is in the transition zone between laminar and turbulent flow.
- Transient simulation: The vortices in transients are the result of the flow changing over time. When the jet hits the surface, the energy of the flow is not immediately dissipated, leading to temporary local vortices.
Solution:
Convert transient simulation to evolution simulation: In evolution simulation, the process is not simulated over time, but Polydata gradually changes the parameters (density, thermal conductivity, heat capacity of mass, ...) from the initial state to the steady state. Helps eliminate oscillation phenomena such as vortex when the flow reaches a steady state.

This is really not recommended because ANSYS Polyflow can only simulate laminar flow and when you simulate with high Reynolds number, you will not get accurate results.

Hope this sharing is helpful to everyone

Regards,
Vu Tuan Khanh