ANSYS Fluent 2D circle external  turbulent transient water flow simulation

Geometry

The geometry was modeled using spaceclaim as 20cm diameter circle inside 3m length*1m width fluid tunnel with the circle center placed 1m away from the inlet

Mesh

Mesh was generated as a cartesian mesh with 5mm mesh size and inflation around the circle wall to catch the boundary layer effect the inflation type is first layer thickness with 15 layer and 0.1mm as first layer thickness

Mesh Quality Metrics and statistics

Mesh Quality of average 0.96871 and standard deviation of 0.10705 shows that the elements are near perfect square in almost all the elements 117'487 elements is sufficient elements number for this preliminary case study in order to save computational resources and time

Model Physics

the physical model settings are 

transient simulation with gravitational acceleration of 9.81 in the -ve Y direction

the turbulence model was set to SST K-Omega with Water as the single phase fluid

and inlet water speed of 1m/s

in solution all the residuals convergence criteria was 0.001"1e-3" that in all time step convergence occurred successfully for X Y velocities around 5e-5 for continuity and omega around 1e-4 for K 1e-3

results

Wall Y+

maximum value of Y+ of 4.901 is extremely efficient and satisfactory

pressure Distribution 

Streamlines

Turbulence