Modelling and simulation of flow through a flowbench

AIM: To create a flowbench geometry and perform parametric study on it.

GEOMETRY:

Flowbench is a testing equipment used to find the effectiveness of the intake port of an IC engine. Here, the inlet port, valve and cylinder have been modelled. The valve is designed in such a way that its opening length could be parameterized.

The dimension 0.005m is the valve opening length and has to be selected while performing a parametric study.

PROCEDURE:

• Create the model and save it
• Open flow simulation add-in
• Create lids at inlet and outlet
• Setup the wizard
• Use internal flow simulation
• Use air as working fluid
• Setup internal conditions
• Create an initial mesh
• Set the boundary conditions as
  • Inlet: Total pressure 11000 Pa
  • Outlet: Static pressure: 10000 Pa
• Setup the contour plots, flow trajectories and goals
• Run the simulation
• Now carry out the same simulation for different meshes until there is no change in the values of setup goals
• This mesh is treated as the final one after performing the mesh independent study
• Now setup a parametric study with the valve opening height as the parameter

RESULTS AND DISCUSSION:

Mesh independent study

This section deals with the results of the mesh independent study that was performed.

1. Global Refinement 3 and local refinement 3

Preliminary decision was made by comparing the values of mass flow inlet and mass flow outlet.

2. Global Refinement 5 and local refinement 4

3. Global Refinement 5, advance channel refinement and local refinement 5

Mesh	Mass flow inlet (kg/s)	Mass flow outlet (kg/s)
Global Refinement 3 and local refinement 3	0.112173	-0.112177
Global Refinement 5 and local refinement 4	0.0907752	-0.097767
Global Refinement 5, advanced channel refinement and local refinement 5	0.0910071	-0.0910087

We find that, the third mesh produces slight variation in results and hence can be used for the simulation.

Parametric study:

Design point 1

Design point 2

Design point 3

Design point 4

Design point 5

From the above parametric study, we find that as the valve lift increases, the mass flow outlet also increases.

I.e. Mass flow rate is proportional to the valve lift

In the cases where valve lift is low, large swirl is observed. Swirl decreases with the increase in valve lift, for this flowbench model.

I.e. Swirl is inversly proportional to the valve lift