Modelling and simulation of flow through a flowbench

Modelling and simulation of flow through a flowbench

Aim: To model the Valve of a Flowbench and to run a grid depended parametric study to calculate the Mass flow rate with respect to Valve lift.

Flowbench

Flowbench is a testing machine that which is used to test aerodynamic quantities of engine component. This device is used to artificially create an Air flow in the system in which the component to be tested are placed. Engine components like carburetors, airlifters, manifolds and other such parts associated with the air or gas flow in the engine is tested using this flowbench.

Components

The basic component used are to produce the thrush air flow into the tunnel and the measuring instruments to measure temperature and pressure.

• Valve
• Air pump
• Metering element
• Manometers
• Test pendulum
• Metering pendulum

Working

The test piece such as manifolds, air filter is attached in series with the pump and measuring element. When the air is pumped through the hole, the testing piece in the metering element get subjected to it, the sir flow in the test piece as well as in the metering element are same with which we can find the mass flow rate using the known pressure and temperature obtained from the Manometers.

Objective

• To model the valve of flowbench.
• To run a primary simulation to find the best grid for the mesh.
• To run a parametric study with the mesh chosen to find the mass flow rate for each of change in the lift of the valve.

Body

The base line simulation is runed by with the boundary conditions

At inlet = Total pressure = 2 bar

At outlet = static pressure = 1 bar

Base line simulation with three different grid levels are tested to select the best grid for parametric study to find the Mass flow rate.

Mesh level = 3

Velocity

Pressure

Mesh level = 4

Velocity

Pressure

Mesh level = 5

Velocity

Pressure

From the results of base line analysis above, we can come to a conclusion that the most effective grid is with the finess of 5 in all the three test from finess 3 to 5.

so, a new parametric study are is done with the grid refinement of 5 with the floowing conditions

The Substance used for actions is air with a time depended test of 0.004 sec

Boundary conditions

At inlet = Total pressure = 2 bar

At outlet = static pressure = 1 bar

Goal Plots

Surface Goals = Mass flow rate at the outlet

Cut plots form pressure and velocity

Flow Trajectories to obtain pressure

The Valve change is set with a minimum difference from 0.001 to max of 0.008 with seven levels in the range of the parametric study.

At valve lift of 0.001

At valve lift of 0.002167

At valve lift of 0.0033

At valve lift of 0.0045

At valve lift of 0.00567

At valve lift of 0.006833

At valve lift of 0.008

The Chage in velocity with respect to Valve Lift

The Chage in pressure with respect to Valve Lift

The change in Mass flow rate with respect to valve Lift

From the Graphs we can see that the mass flow rate decreases with incresse in the valve lift which states that the amount of substance entering inside the container decreases with unt time with increase in Port.

Conclusion: From all the graphs we can come to the conclusion that the velocity and pressure increases with increase in the port length and the mass flow rate decreases with increase in the valve lift.