Modelling and simulation of flow through a flowbench
MODELING AND SIMULATION OF A FLOW THROUGH THE FLOW BENCH
INTRODUCTION:
An airflow bench is a device that is used for testing the internal aerodynamic qualities of an engine component and is related to the more familiar wind tunnel. It is used primarily for testing the intake and exhaust ports of cylinder heads of internal combustion engines.
AIM:
To perform modeling and simulation of flow through a flow bench and to determine the mass flow rate against the valve lift.
OBJECTIVE:
- To perform the Grid dependence test –and to take three grids run the simulation at a particular valve lift and to explain your results
- Effect of valve lift on mass flow rate and run a parametric sweep to show the effect of valve lift on the mass flow rate
PROCEDURE:
- The cylinder was created (0.08 m) and the sweep profile(0.02m) was created in another plane
- The valve is designed at the front plane by creating an axis near the converging end of the sweep profile and the cylinder.
- The valve opening distance is given as 1 mm and the valve has been designed with constraints
- The flow simulation was performed by giving the general settings and the initial conditions in the wizard
- Boundary conditions were given for static pressure (101325) at the outlet and total inlet pressure(405300) was given
- Run the basic parametric study with the mesh value at level 3 and obtain the results
- The grid dependency test was then performed at the various mesh level’s(4,5 &7) and the perfect level was taken for the valve lift test
- The valve lift against the mass flow test was performed by giving the mesh value at level 5(since level 7 was not compatible with my system).
- The plots and results are obtained.
RESULTS AND PLOTS:
GRID DEPENDENCY TEST AT 0.001m VALVE LIFT:
1) velocity plot in automatic grid level-4
2) velocity plot in automatic grid level-5
3) velocity plot in automatic grid level-7
RESULT- as the grid level increases the profile obtained seems quite smooth and clear.as my system supports the grid level 5 better than 7 , I perform the rest of the simulation in level 5.
EFFECT OF VALVE LIFT OF ON MASS FLOW RATE:
The valve lift on mass flow rate test simulation was performed at the level “5” of the automatic grid (mesh level).
The valve is lifted between the 0.001m to 0.008m in order to obtain the mass flow rate at "7" intervals.
Valve lift at 0.001 m:
Velocity cut plot
pressure cut plot
Valve lift at 0.00216 m:
Velocity cut plot
Pressure cut plot
Valve lift at 0.0033m:
Velocity cut plot
pressure cut plot
Valve lift at 0.0045 m:
Velocity cut plot
Pressure cut plot
Valve lift at 0.0056m:
Velocity cut plot
Pressure cut plot
Valve lift at 0.006833m:
as the valve reaches this stage , the velocity increases quite higher than previous lifts.
Velocity cut plot
Pressure cut plot
Valve lift at 0.008m:
here the pressure and velocity values reach the maximum value.
Velocity cut plot
Pressure cut plot
FLOW TRAJECTORY:
Graph of mass flow rate VS valve lift:
| valve lift | SG Mass Flow Rate 1 [kg/s] |
| 0.001 | 0.043201327 |
| 0.00216 | 0.094074973 |
| 0.003333333 | 0.130666476 |
| 0.0045 | 0.151801715 |
| 0.005666667 | 0.15977372 |
| 0.006833333 | 0.161289119 |
| 0.008 | 0.161369586 |
CONCLUSION:
The mass flow rate increases with the valve lift from 0.001m to 0.008m and that are due to the variation of the valve position. as the fluid enters the valve is at 0.001m, fluid enters at a rate of 0.043 between the cylinder and the valve and that flow are is too small. But after the increase in valve lift values the mass flow rate reaches the value of 0.1613 at 0.008m.
in order to obtain the results accurately, the grid-level has to be selected between the 4,5&7 levels and I have taken level 5 as it has quite a good refinement level than 4 but less accurate than 7.(the system doesn't support the mesh level 7 as it requires a high compatible system)