Wavy vortex flow
Posted: Wed Apr 09, 2014 10:01 am
Hello everybody,
I'm working on the Taylor-Couette setup with Code Saturne version 3.0.3. I have succesfully computed for the stable Taylor vortex flow (inner-cylinder rotation set with cs_boundary_conditions subroutine, outer cylinder stationary). For this case a 250,000 element mesh was sufficient.
I am now testing for wavy vortex flow. I set the inner cylinder rotation speed at 19.05 rad/s, which according to the geometry and experiments performed, should result in the wavy vortex flow regime.
I am expecting a periodic Z-velocity component at the monitoring points. After a first transient response, the solution seems to be periodic, but is eventually damped and finally converges to a steady solution with no periodicity. For this case I am using a finer mesh, 1 million elements, a time step of 0.005 and 4000 iterations.
I tested with other angular velocities with the same result, periodicity for a while but converges to a steady solution.
Any ideas on why this happens and how to achieve the periodic solution?
I attach the listing file, compile.log, preprocessor.log, xml file, user subroutines, and the probes_velocityZ.csv and probes_velocityY.csv files.
I attach images of the mesh. It consists of hexahedral elements, 50 in radial direction (finer close to the inner_wall and outer _wall), 100 equidistant elements in axial direction, and 200 equidistant elements in azimuthal direction.
Note: I modified the clptur.f90 file in order to extract the friction velocity and used cs_user_modules and cs_user_postprocess_var to output the wall shear stress.
Thank you for the support,
Best regards
Carlos
I'm working on the Taylor-Couette setup with Code Saturne version 3.0.3. I have succesfully computed for the stable Taylor vortex flow (inner-cylinder rotation set with cs_boundary_conditions subroutine, outer cylinder stationary). For this case a 250,000 element mesh was sufficient.
I am now testing for wavy vortex flow. I set the inner cylinder rotation speed at 19.05 rad/s, which according to the geometry and experiments performed, should result in the wavy vortex flow regime.
I am expecting a periodic Z-velocity component at the monitoring points. After a first transient response, the solution seems to be periodic, but is eventually damped and finally converges to a steady solution with no periodicity. For this case I am using a finer mesh, 1 million elements, a time step of 0.005 and 4000 iterations.
I tested with other angular velocities with the same result, periodicity for a while but converges to a steady solution.
Any ideas on why this happens and how to achieve the periodic solution?
I attach the listing file, compile.log, preprocessor.log, xml file, user subroutines, and the probes_velocityZ.csv and probes_velocityY.csv files.
I attach images of the mesh. It consists of hexahedral elements, 50 in radial direction (finer close to the inner_wall and outer _wall), 100 equidistant elements in axial direction, and 200 equidistant elements in azimuthal direction.
Note: I modified the clptur.f90 file in order to extract the friction velocity and used cs_user_modules and cs_user_postprocess_var to output the wall shear stress.
Thank you for the support,
Best regards
Carlos