Converge CFD

Channel flow simulation using Converge CFD

OBJECTIVE- Simulate channel flow for three different mesh sizes.

Case-1:  Grid size- dx=3e-3 m, dy=3e-3 m, dz=3e-3 m

Case-2: Grid size- dx=2.5e-3 m, dy=2.5e-3 m, dz=2.5e-3 m

Case-3: Grid size- dx=2e-3 m, dy=2e-3 m, dz=2e-3 m

Geometry-A geometry was created for the channel.

Setup-

Applications-

-General flow

Materials-

-Air

Simulation Parameters:

-Pressure based steady state solver

-Start time-0, End time-30000 cycle

-Intial time step=minimum time step=1e-9 s

-Maximum time step=1 s

Boundary conditions-

-Inlet- INFLOW-Total pressure-100001 pa

-Outlet- OUTFLOW-Total pressure-100000 pa

-Top & bottom- WALL

-Front- 2D

-Back – 2D

Regions & Initialization:

Boundaries are assigned to region

Temperature and pressure set to 300K and 100001pa

Species-Air

Case-1:  Grid size- dx=3e-3 m, dy=3e-3 m, dz=3e-3 m

Mesh-

Total cell count:

11000

Mass flow rate at inlet:

The plot shows that the solution has converged.

Mass flow rate at outlet:

Pressure plot at inlet:

Pressure plot at outlet:

Velocity plot at outlet:

Results-

Velocity Contour:

Pressure Contour:

Velocity profile at 0.05 m from inlet:

Pressure drop across length:

Case-2: Grid size- dx=2.5e-3 m, dy=2.5e-3 m, dz=2.5e-3 m

Mesh-

Total cell count:

16000

Mass flow rate at inlet:

The plot shows that the solution has converged.

Mass flow rate at outlet:

Pressure plot at inlet:

Pressure plot at outlet:

Results-

Velocity Contour

Pressure Contour

Velocity profile at 0.05 m from inlet:

Pressure drop across length:

Case-3: Grid size- dx=2e-3 m, dy=2e-3 m, dz=2e-3 m

Mesh-

Total cell count:

26000

Mass flow rate at inlet:

The plot shows that the solution has converged.

Mass flow rate at outlet:

Pressure plot at outlet:

Pressure plot at inlet:

Results-

Velocity Contour

Pressure Contour

 

Velocity profile at 0.05 m from inlet:

Pressure drop across length:

 

Animation:

From the animation it can be seen that at the begining the flow hasn’t reached steady state but after few seconds it reached steady state when the initial solution was washed out.

 

Conclusion:

1. The simulation was run for three different cases.

2. The mass flow rate plot indicates the solution has converged as it reached a constant value after certain cycles.

3. Pressure contour indicate that the flow is driven by pressure difference across the channel.

4. The velocity profile is parabolic which resembles the flow inside a channel.

5. As the mesh gets finer the velocity profile gets smoother at the section.

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