Modelling and simulation of flow through a flowbench

INTRODUCTION:

An airflow 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 primarily used for testing the intake and exhaust ports of cylinder heads in an internal combustion engine. it is also used to test the flow capabiities of air fiter, carburetors,manifolds or any other part that is required to flow air or gas.

A flow bench consists of an air pump of some sort,a metering element,pressure and temperature measuring instruments such as manometers and various controls. The test piece is attached in series with the pump and measuring element and air is pumped through the whole system.Therefore,all the air passing through the meter ngelement also passes throughthe test piece. Because the volume flow rate through the metering element is known and the flow through the test pieceis 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.

PROCEDURE:

• Create a geometry of a flow bench with an inlet port and a cylinder outlet, and the valve.
• To conduct an airflow simu ation throughthe flow bench, create a new project and specify the initial conditions and select the type of fluid as air.
• Then create lids at the inlet and outlet and specify the inlet total pressure and outlet static pressure as the boundary conditions.
• Set global and surface goals of the mass flow rate through the flow bench.
• Create cutplots of the velocity and the pressure,and surface goal plot of the mass flow rate through the flow bench.
• Now generate a new parametric study, and specify the dimension parameter as the valve lift dimensions, and vary the dimensions as 2mm,4mm,6mm, 8mm,10mm.
• Also, specify the input parameters of total pressure inlet, static pressure outlet,and the initial temperature.
• Now return the required output such as cut plots, flow trajectory, goal plot, and the mass flow rate at the surface
• Finally, run the parametric study and get the required results and output plots.

Observation and the Results:

From the above study of valvelift analysis,itis observed that the va ue of the mass flow rate of air (fluid)leavingthe surface increases as the valve-lift at the cylinder inlet increases. The negative(-ve) sign of the mass flow rate indicates that the fluid (air) is leaving the domain.

And the velocity increases as the valve-liftincreases and pressure decreases as the air flows from high pressure to low pressure.