Modelling and simulation of flow through a flowbench

Introduction:

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.

The Mass flow rate is defined as the rate of movement of liquid mass through a unit area. The mass flow is directly depended on the density, velocity of the liquid and area of cross-section. It is the movement of mass per unit time.

Objective:

Creating a 3D model of a flow bench and run flow analysis.

• Grid dependence test - For three grids run your simulation at a particular valve lift and interpolating the results.
• Effect of valve lift on mass flow rate - Once the best grid is decided, run a parametric sweep to show the effect of valve lift on mass flow rate.

Fluid considered - water

Flow bench design:

Boundary conditions:

Inlet-1 bar

outlet- 0.5 bar

GRID DEPENDENCY TEST:

CASE 1:

CASE 2:

CASE 3:

CASE	GRID X-direction	GRID Y-direction	GRID Z-direction	PRESSURE(Pa) MAX	VELOCITY(m/sec) MAX	Remarks
1	20	40	20	93956	9.307	good
2	40	80	40	93737	10.733	comparitively good than case 1
3	60	120	60	95430	11.46	Fine plots are obtaind which can show the pressure and velocity clearly

Flow visualization:

valve lift:

Goal (Value)	Design Point 1	Design Point 2	Design Point 3	Design Point 4	Design Point 5	Design Point 6	Design Point 7	Design Point 8
valve Lift [m]	0.001	0.002285714	0.003571429	0.004857143	0.006142857	0.007428571	0.008714286	0.01
GG Mass Flow Rate [kg/s]	1.61559E-06	-9.39451E-06	-6.90393E-07	3.88992E-06	-1.25195E-05	-6.45421E-06	-7.31396E-06	-1.40826E-05
SG Mass Flow Rate [kg/s]	-0.19323926	-0.320606172	-0.387515387	-0.41820506	-0.427463539	-0.433615176	-0.435732899	-0.436132448

Conclusion:

1. The grid dependency test can give how the fine tuning of mesh can give the more accurate values. more and more increaing the grid the results will be more accurate.

2. The mass flow rate decreases as the valve lift increases.