[josephlm]

I have been trying to simulate the 2D lid driven cavity flow using the SIMPLE algorithm on the staggered grid, in which velocity is assumed to be coupled with pressure and momentum equations are iterated and u, v and pressure p are corrected by a correction term u_corr, v_corr and p_corr respectively. The looping stops when p_corr decreases to a sufficiently small value.

However, the flow obtain does not seem to look like how it should look like, i.e. a main vortex at the centre with counter vortices at the bottom corners. Instead, the plot I obtained shows the boundary conditions (Lid velocity at top, with no-slip condition at other walls), but the velocity arrows in the middle seem to be of a magnitude 100 times smaller than lid velocity and in random directions. It would appear that I have a problem with the correction terms, u_corr, v_corr and p_corr being too small, but i checked the discretized equations over and over and they seem to be correct..

Does anyone know what could be the likely reason for this? Appreciate any help or suggestions to modify my code!

[bikash89]

I have been also facing similar kind of problem. In my case after few iterations oscillations start and the solution fails. However the same code worked really well for Coutte flow. Can ne1 help??

Originally Posted by josephlm

I have been trying to simulate the 2D lid driven cavity flow using the SIMPLE algorithm on the staggered grid, in which velocity is assumed to be coupled with pressure and momentum equations are iterated and u, v and pressure p are corrected by a correction term u_corr, v_corr and p_corr respectively. The looping stops when p_corr decreases to a sufficiently small value.

However, the flow obtain does not seem to look like how it should look like, i.e. a main vortex at the centre with counter vortices at the bottom corners. Instead, the plot I obtained shows the boundary conditions (Lid velocity at top, with no-slip condition at other walls), but the velocity arrows in the middle seem to be of a magnitude 100 times smaller than lid velocity and in random directions. It would appear that I have a problem with the correction terms, u_corr, v_corr and p_corr being too small, but i checked the discretized equations over and over and they seem to be correct..

Does anyone know what could be the likely reason for this? Appreciate any help or suggestions to modify my code!

[mensacorp]

Originally Posted by josephlm

I have been trying to simulate the 2D lid driven cavity flow using the SIMPLE algorithm on the staggered grid, in which velocity is assumed to be coupled with pressure and momentum equations are iterated and u, v and pressure p are corrected by a correction term u_corr, v_corr and p_corr respectively. The looping stops when p_corr decreases to a sufficiently small value.

However, the flow obtain does not seem to look like how it should look like, i.e. a main vortex at the centre with counter vortices at the bottom corners. Instead, the plot I obtained shows the boundary conditions (Lid velocity at top, with no-slip condition at other walls), but the velocity arrows in the middle seem to be of a magnitude 100 times smaller than lid velocity and in random directions. It would appear that I have a problem with the correction terms, u_corr, v_corr and p_corr being too small, but i checked the discretized equations over and over and they seem to be correct..

Does anyone know what could be the likely reason for this? Appreciate any help or suggestions to modify my code!

Hi

Do you have to solve your system with SIMPLE algorithm? I mean you can use picard iteration which is also very simple. I just wrote a 2D Navier Stokes code for Matlab which iterates the solution of matrix K by using picard iterations. It gives reasonable results for the cavity problem.

[Dhileep T K]

Hi,
i have written a matlab code for a 2D natural convection problem using malalasekara versteeg as reference. can you suggest me some reference books for lid driven cavity problem.

[chandanvarma07]

Hello everyone,

Inspired by the insightful teachings of Prof. Sandip Mazumder on YouTube, I have constructed a CFD code entirely from scratch using MATLAB for a classic problem: the lid-driven cavity flow. My goal is to implement a co-located mesh approach and harness the capabilities of the SIMPLE algorithm to ensure accurate pressure-velocity coupling. But after running the code, the residuals were blowing upto infinity.

In the early stages of debugging, I closely monitored the simulation's behavior. The initial iteration yielded a promising outcome, with both X and Y momentum well-preserved—a strong validation of my approach. Employing the TDMA method, I've attached an x momentum contour from the first iteration for your reference, exhibiting similarities to patterns observed in heat conduction cases solved by the ADI Method.

However, as I delved further into debugging, a significant challenge emerged: accurately calculating face velocities. It became evident that inaccuracies at this step were rippling through the simulation, affecting pressure source term calculations and subsequently impacting the pressure correction data. Notably, certain cells exhibited discrepancies between the sign of pressure source terms and correction data.

Through careful examination, I've begun to explore whether the absence of appropriate boundary conditions in face velocity calculation might contribute to these disparities. This has prompted a deeper consideration of boundary condition implementation and its potential influence on this critical simulation stage.

To provide a comprehensive view of my progress, I've attached the code I've been diligently working on. Your insights and expertise in reviewing this code would be invaluable in helping me address these challenges.