Modelling and simulation of flow through a flowbench

An airflow 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 primarily used for testing the intake and exhaust ports of cylinder heads in an internal combustion engine. it is also used to test the flow capabilities of air filter, carburetors, manifolds or any other part that is required to flow air or gas.  
A flow bench consists of an air pump of some sort, a metering element, pressure and temperature measuring instruments such as manometers and various controls. The test piece is attached in series with the pump and measuring element and air is pumped through the whole system. Therefore, all the air passing through the metering element also passes through the test piece. Because the volume flow rate through the metering element is known and the flow through the test piece is the same, it is also known. The mass flow rate can be calculated using the known pressure and temperature data to calculate air densities and multiplying by the volume flow rate.
In this project, we are going to model the flow bench and simulate the airflow from the inlet port to the outlet using Solidworks.



AIM: This study aims to model the flow bench geometry and carry on the simulation of the airflow flow from an inlet port to the outlet. also, we are going to calculate the mass flow rate (µ) at various valve lift and create the cut plots for velocity and pressure using Solidworks.

PROCEDURE:

Create a geometry of a flow bench with an inlet port and a cylinder outlet, and the valve.

To conduct an airflow simulation through the flow bench, create a new project and specify the initial conditions and select the type of fluid as air.

Then create lids at the inlet and outlet and specify the inlet total pressure and outlet static pressure as the boundary conditions.

Set global and surface goals of the mass flow rate through the flow bench.

Create cutplots of the velocity and the pressure, and surface goal plot of the mass flow rate through the flow bench.

Now generate a new parametric study, and specify the dimension parameter as the valve lift dimensions, and vary the dimensions as 2mm, 4mm, 6mm, 8mm, 10mm.

Also, specify the input parameters of total pressure inlet, static pressure outlet, and the initial temperature.

Now return the required output such as cut plots, flow trajectory, goal plot, and the mass flow rate at the surface goal.

Finally, run the parametric study and get the required results and output plots.

GRID DEPENDENCY TEST:

 Conducting a grid dependency test in the parametric study for mesh refinement 3, 4, 5,

Results of the grid dependency test:

Velocity Plot for mesh refinement 3:


Velocity Plot for mesh refinement 4:


Velocity Plot for refinement 5:

From the above study on the grid dependency test, it is observed that the mesh refinement value or grid value of 5 gives varied results for the velocity plot and gives an accurate value of the mass flow rate.
So from here on we are going to select the grid size 5 as the best grid and continue with our experimentation.

F0R A GRID SIZE OF 5,

OUTPUT and PLOTS:

For a valve-lift of 2mm (0.002m),

Velocity plot:


Mass flow rate:



Flow trajectory :



Lift= 4mm

Velocity Profile:


Mass flow rate:


Flow trajectory:



Lift=6mm
Velocity Profile:


Mass flow rate:


Flow Trajectories:



Lift=8mm

velocity Profile:


Mass flow rate:

Flow Trajectory:

Lift=10mm

Velocity Profile:

Mass Flow rate:

Flow Trajectory:

PARAMETRIC STUDY :

VARIOUS GRAPHS:

Observation and the Results:

From the above study of valve lift analysis, it is observed that the value of the mass flow rate of air (fluid) leaving the surface increases as the valve-lift at the cylinder inlet increases. The negative(-ve) sign of the mass flow rate indicates that the fluid (air) is leaving the domain.
And the velocity increases as the valve-lift increases and pressure decreases as the air flows from high pressure to low pressure.