Modelling and simulation of flow through a flowbench

AIM : Creating a 3D model of a Flow Bench and runing the flow analysis & perform the following operations.

• Grid dependence test.
• Effect of valve lift on mass flow rate.

OBJECTIVES :

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 at various valve lift and create the cut plots for velocity and pressure using Solidworks.

CYLINDER DIMENSIONS :

Bore diameter is 50mm.

Length of cylinder 100mm.

Intake manifold diameter is 25mm.

BOUNDARY CONDITION :

Inlet total pressure 172369[Pa] at temperature 293.2[K].

Outlet static pressure 101325[Pa] at temperature 293.2[K].

Wall type is taken as the real wall.

GEOMETRY :

PROCEDURE :

1. Create a geometry of a flow bench with an inlet port and a cylinder outlet, and the valve.
2. 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.
3. Then create lids at the inlet and outlet and specify the inlet total pressure and outlet static pressure as the boundary conditions.
4. Set global and surface goals of the mass flow rate through the flow bench.
5. Create cutplots of the velocity and the pressure, and surface goal plot of the mass flow rate through the flow bench.
6. 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.
7. Also, specify the input parameters of total pressure inlet, static pressure outlet, and the initial temperature.
8. 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.

Velocity plot for mesh refinement-3 :

Velocity plot for mesh refinement-4 :

Velocity plot for mesh 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, we select grid size 5 as the best grid and continue with our experimentation.

Results of the grid dependency test:

OUTPUT & PLOTS :

• For a valve-lift of 2mm (0.002m),

Velocity plot:

Pressure plot:

Graph of mass flow rate:

Flow trajectory of velocity:

• For a valve-lift of 4mm (0.004m) :

Velocity plot:

Pressure plot:

Graph of mass flow rate:

Flow trajectory:

• For a valve-lift of 6mm (0.006m):

Velocity plot:

Pressure plot:

Graph of mass flow rate:

Flow trajectory:

• For a valve-lift of 8mm (0.008m):

Velocity plot:

pressure plot:

Graph of mass flow rate:

Flow trajectories:

• For a valve-lift of 10mm (0.010m) :

Velocity plot:

pressure plot:

Graph of mass flow rate:

Flow trajectories:

Variation in mass flow rate values versus iteration:

Graph showing mass flow rate values at different valve-lifts:

OBSERVATION & RESULTS :

1. 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.
2. The negative(-ve) sign of the mass flow rate indicates that the fluid (air) is leaving the domain.
3. The velocity increases as the valve-lift increases and pressure decreases as the air flows from high pressure to low pressure.