Modelling and simulation of flow through a flowbench

Objective :

Internal flow analysis of Flow Bench Geometry using Solidworks Flow Simulation.

1. Performance of a parametric test for the Grid dependence of the analysis.
2. Analyzing the flow characteristics under various valve lifts.
3. To calculate the mass flow rate vs valve lift

Introduction :

An air flow bench is a device used for testing the internal aerodynamic qualities of an engine component and is related to the more familiar wind tunnel. It is used primarily for testing the intake and exhaust ports of cylinder heads of internal combustion engine.

Model –

Grid dependency test is the analysis of a model under the same condition with different mesh refinement. This test obtains the ideal grid refinement number for the simulation.

Procedure :

1. We will first open Solidworks part modeling to design the Flow Bench.
2. Dimensions –

Bore diameter of the cylinder = 0.1m

Length of the bore = 0.1m

3. A port is created using sweep command and then get inside cavity we used the shell command.
4. Finally a valve is created using the revolve command.
5. Here the valve lift is 1mm. the lids are created at two ends of the flow bench.

Flow Simulation –

1. Boundary conditions –

At the inlet side of the port (lid1) – total pressure (401325 pa)

At the outlet side of the cylinder (lid2) – static pressure (101325 pa)

2. Goals –

Global mass flow rate and surface mass flow rate.

3. Meshing –

Automatic mesh level – 3 with advance refinement

Global mesh -

Local mesh –

Grid Dependency Test :

1. New parametric study – Grid Dependency Test

In order to select level of refinement, we run a parametric test where constant valve lift of 1mm. We define the 3 different grid sizes ranging from 3 to 5. Also we check the velocity and pressure plots for these 3 values.

Results -

• Grid size 3

Velocity plot (valve lift 1mm)

Pressure plot ( valve lift 1mm) –

• Grid size 4

Velocity plot (valve lift 1mm)

Pressure plot (valve lift 1mm)-

• Grid size 5

Velocity plot (valve lift 1mm)

Pressure plot (valve lift 1mm)-

Graph of grid dependency test -

Observations –

1. From the graph, we can see that as the refinement level increases mass flow rate is also increases.
2. After seeing the velocity and pressure plots, for proper results and plots description, we go with grid size 4. Although we may go for the higher value but it will take higher computation time.

Valve Lift Test :

With a grid size of 4, we run another parametric study where we change the valve lift from 0.001m to 0.005m with 5 intervals. In this study we are looking for the velocity and pressure plots, mass flow rate of different valve lift, flow trajectories .

Results –

(for mesh level 4)

• Valve lift at 0.001m

Velocity plot (mesh size 4)

Pressure plot (mesh size 4)

Flow trajectory of valve lift at 0.001m

• Valve lift at 0.002m

Velocity plot (mesh size 4)

Pressure plot (mesh size 4)

Flow trajectory of valve lift at 0.002m

• Valve lift at 0.003m

Velocity plot (mesh size 4)

Pressure plot (mesh size 4)

Flow trajectory of valve lift at 0.003m

• Valve lift at 0.004m

Velocity plot (mesh size 4)

Pressure plot (mesh size 4)

Flow trajectory of valve lift at 0.004m

• Valve lift at 0.005m

Velocity plot (mesh size 4)

Pressure plot (mesh size 4)

Flow trajectory of valve lift at 0.005m

Graph :

The plot valve lift vs mass flow rate –

Conclusion :

1. From the cut plots we can see that the velocity of the flow increases as the valve lift increases.
2. From the cut plots we see that the pressure reduces as the valve lift increases.
3. And mass flow rate increases as the valve lift increases.