Modelling and simulation of flow through a flowbench

AIM:
To perform the flow simulation through a flow bench by modeling the geometry and obtaining a plot of lift vs mass flow rate.

OBJECTIVE:
• To perform a Grid dependence test.
• Simulating three grids at a particular valve lift.
• To perform the effect of valve lift on mass flow rate.
• Running a parametric sweep to show the effect of valve lift on mass flow rate.

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. 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 metering element also passes through the test piece. Because the volume flow rate through the metering element is known and the flow through the test piece is 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.

Simulation Setup:

• Model of flowbench is made.
• After sketching, flow simulation was setup and lids were given at two openings and following parameters were given as inputs
• Analysis Type: Internal,
• Type of fluid: Air,
• Type of flow: Laminar and Turbulant,
• Wall conditions: Adiabatic
• Total Inlet Pressure = 5*101325 = 506625
• Static Pressure (outlet) = 101325

Grid Test:

Considering the Valve Lift at 0.001m

Case 1 (For grid mesh size = 3):

Case 2 (For grid mesh size = 4):

Case 3 (For grid mesh size = 5):

CONCLUSION for Grid Test:
In the above three cases, the results are getting smoother and accurate concerning an increase in the grid dependency levels. However considering my system configurations, I choose grid mesh size of 3. Note: I used local mesh around value to get better results.

EFFECT OF VALVE LIFT ON MASS FLOW RATE:

Case 1: valve lift is 0.001mm

Case 2: valve lift is 0.002mm

Case 3: valve lift is 0.003mm

Case 4: valve lift is 0.004mm

Case 5: valve lift is 0.005mm

Case 6: valve lift is 0.006mm

Case 7: valve lift is 0.007mm

Case 8: valve lift is 0.008mm

Main Plot:

Conclusion:
Generally, Mass flow rate is the mass of a substance that passes per unit of time. From the graph, it is clear that as the value of valve lift increases, the mass flow rate increases this is due to the gap between the circular sweep profile and cylinder