Modelling and simulation of flow through a flowbench
AIM: To study the internal flow analysis of flow bench and to perform parametric study for different cases of valve lift
Theoritical background:
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
It is used primarily for testing the intake and exhaust ports of cylinder heads of IC engine. 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 amount of pressure loss that occurs when the fluid flows through this intake port tells us how well the port has been designed. If there is a lot of presssure loss its going to increase your pumping cost. To minimize that port should have minimum pressure drop as possible
Solid modeling Computational Domain
Meshing
Baseline setup
Velocity contour on cut plot Pressure contour on cut plot
Grid Dependency Test
For grid size of 4mm
Velocity Contour Pressure Contour
For grid size of 5mm
Velocity Contour Pressure Contour
For grid size of 6mm
Velocity Contour Pressure Contour
Output results of parametric study of Grid Dependency Test
Observations:
There is a varation in flow in the velocity contour no change in flow in the pressure contour for 3 different mesh size. Grid size of 5 is considered for further study.
Valve lift test
Valve lift:
The valve lift is the distance by which the valve is raised from its seated position when it is fully opened. The camshaft controls the speed of valve opening, valve lift off the valve seat, and how long the valve stays open. More cam lift means the valve will open further. Increasing cam lift will allow more air or exhaust to move through an engine. Increasing valve lift allows more open space in the intake and exhaust ports of the cylinder. Theoretically, this means more air and fuel can be drawn in. More exhaust gases can be pushed out.
Valve lift = 0.0015m
Velocity contour Pressure contour
Valve lift = 0.0020m
Velocity contour Pressure contour
Valve lift = 0.0025m
Velocity contour Pressure contour
Valve lift = 0.0030m
Velocity contour Pressure contour
Valve lift = 0.0035m
Velocity contour Pressure contour
Valve lift = 0.0040m
Velocity contour Pressure contour
Valve lift = 0.0045m
Velocity contour Pressure contour
Valve lift = 0.0050m
Velocity contour Pressure contour
Output results of parametric study of Valve lift
Observations:
1] Mass flow rate reduces as the valve lift increases because improve in the valve lift makes more input of mixture in to the flowbench. In this case mass flow rate is coming in negative trend because the working fluid is moving out of the domain.
2] We can observe from the pressure plot that as the valve lift increases the pressure decreases and the velocity increases.
3] The swirling effect is more at regions of high pressure and decreases in cases of more valve lift.