-
-
February 7, 2023 at 5:12 am
abhnv_01
SubscriberI am trying to simulate a heat pipe in (2D) which has three sections:
- Evaporator - Constant heat flux (boundary conditions)
- Condensor - Constant temperature (boundary conditions)
- Adiabatic section - Zero heat flux (boundary conditions)
I am using VOF multiphase model -> Evaporation - condensation model -> Lee model.
Transient simulation with gravity and implicit body force formulation.
Time step size = 0.0001 (1E-04).
The simulation works well for first 10000 time steps (1 seconds of flow time) and then this error where global courant number exceeds 250.
But here is a mystery, the simulation runs well with constant temperature boundary condition at the evaporator.
I want results with constatn heat flux, I am not able to track the error, any help will be highly appreciated.
-
February 7, 2023 at 6:05 am
SRP
SubscriberHi,
I suggest to try variable time stepping in order to automatically change the time-step. It is better to use the variable time stepping method to control the CFL under limit. The solution will be stable with the variable time stepping method.
Thank you
Saurabh
-
- You must be logged in to reply to this topic.

Boost Ansys Fluent Simulations with AWS
Computational Fluid Dynamics (CFD) helps engineers design products in which the flow of fluid components is a significant challenge. These different use cases often require large complex models to solve on a traditional workstation. Click here to join this event to learn how to leverage Ansys Fluids on the cloud, thanks to Ansys Gateway powered by AWS.

Earth Rescue – An Ansys Online Series
The climate crisis is here. But so is the human ingenuity to fight it. Earth Rescue reveals what visionary companies are doing today to engineer radical new ideas in the fight against climate change. Click here to watch the first episode.

Ansys Blog
Subscribe to the Ansys Blog to get great new content about the power of simulation delivered right to your email on a weekly basis. With content from Ansys experts, partners and customers you will learn about product development advances, thought leadership and trends and tips to better use Ansys tools. Sign up here.
- Suppress Fluent to open with GUI while performing in journal file
- Floating point exception in Fluent
- What are the differences between CFX and Fluent?
- Heat transfer coefficient
- Getting graph and tabular data from result in workbench mechanical
- The solver failed with a non-zero exit code of : 2
- Difference between K-epsilon and K-omega Turbulence Model
- Time Step Size and Courant Number
- Mesh Interfaces in ANSYS FLUENT
- error in cfd post
-
3744
-
2573
-
1797
-
1236
-
594
© 2023 Copyright ANSYS, Inc. All rights reserved.