Modelling and simulation of flow through a flowbench
FLOW BENCH:
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.
Since 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.
AIM:
To perform the flow simulation through a flow bench by modelling the geometry and obtaining a plot of lift vs mass flow rate.
OBJECTIVE:
- To perform Grid dependence test.
- Running the simulation for three grids at a particular valve lift.
- To perform the effect of valve lift on mass flow rate.
- Running a parametric sweep to show the effect of valve lift on mass flow rate.
PROCEDURE:
3D MODEL:
Part of flow bench:
|
Input Conditions |
Values |
|
Analysis Type |
Internal Flow |
|
Fluids |
Air |
|
Units |
SI units |
|
Total Inlet Pressure |
4*101325 = 405300 |
|
Static Pressure (outlet) |
101325 |
GRID DEPENDENCY TEST:
Considering the Valve Lift at 0.001m
CASE 1: Velocity plot in grid level 4
Pressure plot
CASE 2: Velocity plot in grid level 5
Pressure plot
CASE 3: Velocity plot in grid level 7
Pressure plot
CONCLUSION – GRID DEPENDENCY TEST:
On the above three cases, the results are getting smoother and accurate with respect to increase in the grid dependency levels.
RESULTS:
EFFECT OF VALVE LIFT ON MASS FLOW RATE:
To view the effect of mass flow rate, increasing the valve lift from 0.001m to 0.008m by 8 equal intervals with global mesh level 5.
Valve Lift at 0.001m
Cut plot: Velocity contour
Cut plot: Pressure contour
Valve Lift at 0.002m
Cut plot: Velocity contour
Cut plot: Pressure contour
Valve Lift at 0.003m
Cut plot: Velocity contour
Cut plot: Pressure contour
Valve Lift at 0.004m
Cut plot: Velocity contour
Cut plot: Pressure contour
Valve Lift at 0.005m
Cut plot: Velocity contour
Cut plot: Pressure contour
Valve Lift at 0.006m
Cut plot: Velocity contour
Cut plot: Pressure contour
Valve Lift at 0.007m
Cut plot: Velocity contour
Cut plot: Pressure contour
Valve Lift at 0.008m
Cut plot: Velocity contour
Cut plot: Pressure contour
FLOW TRAJECTORY:
Velocity contour:(for design plot1 0.001mm)
When arrow is selected the following plot appears
When pipe is selected the below plot appears
GRAPH:
Here the graph is plotted between the valve lift vs mass flow rate from 0.001m to 0.008m. The mass flow rate for the respective valve lift is been provided below:
|
Valve Lift |
Mass Flow rate |
|
0.001 m |
0.0434 |
|
0.002 m |
0.0895 |
|
0.003 m |
0.1210 |
|
0.004 m |
0.1446 |
|
0.005 m |
0.1569 |
|
0.006 m |
0.1603 |
|
0.007 m 0.008 m |
0.1605 0.1605 |
SUMMARY FOR THE GOAL PLOTS:
Valve Lift vs Mass Flow rate:
The above graph shows that the increase in valve lift, the mass flow rate is getting increase with a constant value.
CONCLUSION:
Grid Dependency Test:
This test is taken to selecting and performing the optimum level of mesh for the mass flow rate in profile geometry of flow bench. Increasing the mesh increases the plot refinement yet medium level of mesh is used according to processor compatibility
Mass Flow rate vs Valve lift:
Generally, Mass flow rate is the mass of a substance which passes per unit of time. From the graph, it is clear that as the value of valve lift increases, the mass flow rate increases this is due to the gap between the circular sweep profile and cylinder.
After a particular lift mass flow value remains constant ,this is due to the sufficient space for air flow.