Modelling and simulation of flow through a flowbench
Flow simulation of Flow bench using Solidworks
Aim: To examine the flow in a flow bench at different valve lifts.
Objective:
- Do Grid dependence test
- Observe the effect of lift on mass flow rate
- Run a parametric study to show the effect of valve lift on mass flow rate
Theory:
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.
It is used primarily for testing the intake and exhaust ports of cylinder heads of internal combustion engines. It is also used to test the flow capabilities of any component such as air filters, carburetors, manifolds or any other part that is required to flow gas. A flow bench is one of the primary tools of high performance engine builders, and porting cylinder heads would be strictly hit or miss without it. 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.
Flow bench generally has two types of ports i.e. helical port and tangential port.
Flow of procedure
First of all, a flow bench is made. MKS system is used while making the part.
Next, flow simulation project is made by using the wizard tool. All the values in the tool are kept constant except name and fluids. Air is specified as fluid.
After that, input data is entered
Boundary conditions - Total inlet pressure as 405300 Pa and static pressure at outlet as 101325 Pa.
Goals – Global goal and surface goal as mass flow rate at outlet.
After setting up the above things, three flow studies are carried out. The refinement of mesh is done to obtain high accuracy.
Case 1: Global grid refinement at 3 and local grid refinement at 3.
Case 2: Global grid refinement at 4 and local grid refinement at 4.
Case 3: Global grid refinement at 4 and local grid refinement at 5.
Local grid refinement is applied at all the faces of valve.
Results acquired while carrying out above study.
Case 1:
Pressure cut plot
Flow trajectories
Case 2:
Pressure cut plot
Flow trajectories
Case 3:
Pressure cut plot
Flow trajectories
After observing the result, a parametric study carried out in case 3. In this study, valve lift is increased 7 times and analysis is done at each lift. The range of lift is 0.005 m to 0.01 m.
Results:
At lift 0.005 m
Pressure cut plot
Flow Trajectories
At lift 0.0058 m
Pressure cut plot
Flow Trajectories
At lift 0.0067 m
Pressure cut plot
Flow Trajectories
At lift 0.0075 m
Pressure cut plot
Flow Trajectories
At lift 0.0083 m
Pressure cut plot
Flow Trajectories
At lift 0.0092 m
Pressure cut plot
Flow Trajectories
At lift 0.01 m
Pressure cut plot
Flow Trajectories
Lift vs Mass flow rate
Conclusion:
In this project it is observed that, accuracy can be increased by refining the mesh. Also, the mass flow rate increases with increase in valve lift. It is observed that as valve lift increases, pressure decreases resulting in increase in velocity. At 0.01m lift the pressure is very low as compared to pressure at 0.005m lift.
Reference: