November 5, 2018 at 12:33 pmAkshay1993Subscriber
I am Akshay Barpute and i am doing my master project on DTU 10 MW offshore wind turbine. I have to perform CFD operations. I have modeled the blade and i have started doing meshing. My problem arises here, without inflation my skweness and orthogonal quality is good i.e max skweness (0.79) and min ortho quality (0.21) but after creating inflation layer it is drastically decreasing. can you please help me to find a solution.
November 5, 2018 at 3:57 pmRobAnsys Employee
You need to look at where the poor cells are being created and then see why they're occurring. Look at the graph for statistics, adjust the scales and then click (hold CTRL) on the top 2-3 bars. This should highlight where the mesh is of poor quality.
November 7, 2018 at 2:02 pmAkshay1993Subscriber
Thank you for the reply.
I have already seen the areas where the mesh is of poor quality. The mesh is poor on the surface of the blade(i.e) at the trailing edge. I have tried to change the design of my blade near the trailing edge(i.e) like round type, straight trailing edge and smooth finish. None have given me good results. what should i do know??????
November 7, 2018 at 2:41 pmRobAnsys Employee
There are a few options:
Increase the surface mesh resolution near the trailing edge as this helps the inflation.
Create an O-grid block around the blade (look this up) as the decomposition faces will aid the inflation layer growth
Check the angle in the inflation advanced settings: increase it to the maximum
Create one fairly thick inflation layer and adapt in Fluent
Simply, you're trying to help the mesh build the layers: this may mean breaking the model up.
November 8, 2018 at 2:26 pmAkshay1993Subscriber
I thank you for your guidence, Sir i have increased the surface mesh resolution near the trailing edge, but there was not much improvement in the mesh and i cannot increase the resolution more as i need to resist the no of cell to 7 million. And i have increased the inflation angle as well.
But i havent tried creating a thick inflation layer . what does it mean can you please explain me ???
i am attaching my ansys file as well for clear understanding.
November 8, 2018 at 3:54 pmRobAnsys Employee
I'm not allowed to open ANSYS files: as staff we operate under several restrictions. Other community members are able to open files.
A thick layer is simply that you create inflation of only 1-2 layers but set the initial height to be much higher than normal. You then use adaption in the solver to refine the mesh as needed. It's an old approach for when thin layers give poor mesh quality.
November 15, 2018 at 11:30 amAkshay1993Subscriber
Luckily I have achieved the quality with inflation layer. Now my problem is that, my solution is not converging. I am using the turbulence model K-Epsilon model. I have used the Yplus value between 30 and 300. I have given the convergence criteria as 1e-6. I am able to get the convergence for K, X, y,, z. but for epsilon and continuity i am not getting convergence. Is there any solution for this?????. should i change the under relaxation factor for the momentum so that there may be a chance for continuity to converge.
November 15, 2018 at 1:23 pmRobAnsys Employee
It'll depend on what the cause is. What you've probably got is some transient behaviour in the flow, put some monitor points into the domain and look for fluctuations. What you're after is flat residuals and monitors, plus low mass imbalance: typically getting two of the list to work is enough but you'll need to understand the flow field to decide.
November 15, 2018 at 2:43 pmAkshay1993Subscriber
Thank you for the reply. What do you mean by monitor points??. I have kept the report definition for lift coefficient and drag and moment coefficient. What do you mean by mass imbalance????. Can you please explain me.
- 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.
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.
- ANSYS Workbench Measuring within Design
- how to improve the inflation quality at sharp corners?
- check element type
- The mesh file exporter could not resolve cyclic dependencies in overlapping contact regions error
- How to resolve Mesh Failure
- Meshing Error
- Error in meshing
- Conformal vs Non-Conformal Mesh
- execution error inside the mesher. The process suffered an unhandled exception or ran out of memory
- inflation created stairstep mesh at some location
© 2023 Copyright ANSYS, Inc. All rights reserved.