Modelling and simulation of flow through a flowbench using SolidWorks
AIM: To do modelling and simulation of flow through a flowbench and do the following-
- Grid Dependency Test
- Effect of Valve lift on mass flow rate
INTRODUCTION
Flowbench is a device which is basically used to design intake port and for testing the internal aerodynamic quality of the engine.
Valve lift is the distance by which the valve is pushed to open.
PROCEDURE
1) Create a cylinder with dimensions shown above then make the circular inlet port by sweeping circular profile.
2) Create axis at the bottom of the intake port then create plan over there and by using that plane create the valve.
3) Make the valve open at 1mm.
4) Save the profile and run the wizard by setting all the conditions.
5) Insert boundary conditions as Total inlet pressure as 401325 and Static pressure at the outlet as 101325.
6) Run the basic simulation then run parametric study by taking Global mesh as input to do the grid dependency test.
5) Constraint the valve in such a way so that the valve can only move to the vertical distance.
6) Now run parametric study by taking Valve open distance as input.
7) Save and conclude the results.
OUTPUT & RESULTS
Grid dependency test at 0.001m Valve lift
Case 1 Velocity plot in automatic grid level 3
Case 2 Velocity plot in automatic grid level 5
Case 3 Velocity plot in automatic grid level 7
CONCLUSION
Hence by grid dependency test, we concluded the following points-
- On increasing the level of grid we got more accurate and smoother looking profile.
- According to my system's configuration automatic grid level 7 is the optimum case to perform the simulations.
Effect of valve lift on mass flow rate
Now we are increasing the valve lift from 0.001 to 0.008 mm in order to see the effect on the mass flow rate.
Valve lift 0.001mm
Velocity plot
Pressure plot
We can observe high pressure at the intake port when the valve is just opened by 1mm.
Valve lift 0.002mm
Velocity plot
Pressure plot
Valve lift 0.003mm
Velocity plot
Pressure plot
Valve lift 0.004mm
Velocity plot
Pressure plot
Valve lift 0.005mm
Velocity plot
Pressure plot
Valve lift 0.006mm
Velocity plot
Pressure plot
Valve lift 0.007mm
Velocity plot
Pressure plot
We can observe low pressure when the valve is nicely opened by 7mm.
Valve lift 0.008mm
Velocity plot
Pressure plot
Flow Trajectory
Graph & table of mass flow rate vs Valve push open dimension is shown below
- Mass flow rate increases as the value of valve lift increases.
- We can see that mass flow rate is getting constant for higher valve lift.
- The negative value of mass flow rate signifies that mass is leaving the system.
| Table: Valve lift vs mass flow rate | |
| Valve lift (m) | Mass flow rate (kg/s) |
| 0.001 | 0.0700 |
| 0.002 | 0.1158 |
| 0.003 | 0.1578 |
| 0.004 | 0.1903 |
| 0.005 | 0.2207 |
| 0.006 | 0.2364 |
| 0.007 | 0.2450 |
| 0.008 | 0.2450 |
CONCLUSION
1) From the velocity plots, we saw as the valve lift increases the velocity of fluid also increases. Hence higher the valve lift higher will be the velocity of fluid.
2) From the pressure plot, we saw as the valve lift increases the pressure of the fluid decreases. Hence higher the valve lift lower will be the pressure of fluid.
3) Mass flow rate increases as the valve lift increases but for higher values of valve lift mass flow rate becomes constant. As we can track from the graph and table of mass flow rate vs valve lift that for 0.007m and 0.008m of valve lift we got exactly the same value for mass flow rate which is 0.2450 kg/s.
4) Higher the level of grid in the mesh more accurate will be the results.