Modelling and simulation of flow through a flowbench

Aim:- "MODELLING AND SIMULATION OF FLOW THROUGH A FLOW BENCH."

1. Objective:-
2. Create a 3D model of a flow bench and run flow analysis. obtaining a plot of lift vs mass flow rate
   ii. Grid dependence test For three grids run your simulation at a particular valve lift and explain your results.
   iii. Effect of valve lift on the mass flow rate
   iv. Once you have decided the best grid, run a parametric sweep to show the effect of valve lift on the mass flow rate

2. Basic:-

An airflow bench is a tool used to assess the internal aerodynamic properties of an engine and is related to a standard air tunnel. It is mainly used to inspect the ports of entry and exhaust cylinder heads for internal assembly engines. It is also used to test the flow capacity of any component such as air filters, carburetors, manifolds or any other component required for gas flow. The flow bench is one of the main tools of an efficient engine builder, and the cooling heads of the cylinder would be crashed or missed without them.
The flow bench consists of an air pump of some sort, a meter object, pressure and temperature measuring devices such as meters, and various controls. The test piece is attached to the pump sequence and the air gauges are taken through the whole system. Therefore, all the air passing through the metering object also passes through the test strip. Because the rate of volume flow through the metering element is known and the flow of the test component is the same, it is known. The flow rate can be calculated using known pressure and temperature data to calculate air flow and then multiplied by the flow rate.
Here we take the only drinking hole and not the port you just got out of because the flow bench uses only those countries to be tested.

Grid dependence test:- The Grid dependence test is also known as the Mesh dependency test in which simulating the same body at a refined mesh size. The grid dependency test plays an important role in the simulation. As the mesh size refines the accuracy of the result is getting high hence it is important to select the proper mesh size to minimize error.

3. Procedure:-

Step-1: Creating the 3D model of a flow bench as shown below.

Step-2: Opening the flow simulation add-in for setting up the simulation parameters. i.e. taking flow type as internal flow and fluid type as air and other parameters.

Step-3: Defining the boundary condition such as Total pressure at the inlet and static pressure at outlet and mass flow rate at the inlet.

Step-4: Setting mesh size and doing Grid dependence test for the best mesh size.

Step-5: Setting parametric study for variable valve lift. We are taking valve lift Variation from 0.001 m to 0.008 m and the number of values is 7. Also setting the input and output variable.

Step-6: Run the calculation.

4. Simulation and Analysis:-

Before analysis, we need to do grid Dependency test to get the appropriate mesh size.

4.1 Grid Dependency Test:-

In the grid dependency test, we are going to use the valve lift of 0.004500m for and the mesh size of 3,4 and 5 respectively.

Simulation Parameters:

Unit	: SI
Static Pressure	:101325 pa
Total Pressure	: 501325 pa
Mass flow rate	: 1 m/s

1. At Refinement level-3:

Cut plot:

Flow Trajectories:

1. At Refinement level-4:

Cut plot:

Flow Trajectories:

iii. At Refinement level-5:

Cut plot:

Flow Trajectories:

from the grid dependency test, we can see that the mesh size 5 is giving more clear result and also the flow trajectories is visualized more clear. Hence in further studies, we will use the mesh refinement level to 5.

4.2 Cases of Valve Lift:-

We are taking valve lift Variation from 0.001 m to 0.008 m and the number of values is 7. In this the mesh size of the 5 for better result. In each valve lift, we are taken the cut plot and the flow trajectories to represent the flow behaviour.

1. At valve lift 0.001m:-

Cut plot:

Flow Trajectories:

1. At valve lift 0.0021667m:-

Cut plot:

Flow Trajectories:

iii. At valve lift 0.003333m:-

Cut plot:

Flow Trajectories:

1. At valve lift 0.004500m:-

Cut plot:

Flow Trajectories:

1. At valve lift 0.005666m:-

Cut plot:

Flow Trajectories:

1. At valve lift 0.006833m:-

Cut plot:

Flow Trajectories:

vii. At valve lift 0.008m:-

Cut plot:

2

Flow Trajectories:

5. Observation and Conclusion:-

From the above simulation and analysis studies, we can conclude the major three result as follows.

5.1 Mass Flow Rate (vs) Valve lift:-

Mass Flow Rate 1 [kg/s] at Design points is as follows.

Design Point 1	Design Point 2	Design Point 3	Design Point 4	Design Point 5	Design Point 6	Design Point 7
-0.095927299	-0.166328182	-0.23742248	-0.292934601	-0.331863903	-0.351788883	-0.357704277

From the weight flow rate structure in relation to the valve lift, we can see that that plan has a negative value that means the exit to the system. which is why when the valve lift increases the flow rate of the weight but is represented by a negative value as discussed.
Also, as the weight flow rate increases relative to the valve that raises the difference it is visible in the first structure above straight. The variability in the line at the top reaches a certain amount after which it increases but the variability in the curve appears to be small and the average weight movement rate is small.
This is due to the return power applied (based on Newton's law 3) by the valve on the fluid flowing in the system. This reversible force is high in the first phase and decreases with increasing valve lift and makes way for the curve in the structure.

5.2 Pressure Drop:-

5.2.1 Pressure drop at design points:

The pressure drop at a design point can be calculated with the formula is given below as,

"Pressure Drop = Maximum Total Pressure at the inlet - Maximum Total Pressure at the Outlet"

Hence the calculated Pressure Drop at Design points (Pa) is as follows.

Design Point 1	Design Point 2	Design Point 3	Design Point 4	Design Point 5	Design Point 6	Design Point 7
396256.8888	391402.8527	386784.7056	386691.9285	386430.9888	387748.0175	385180.1489

5.2.2 Overall Pressure Drop:-

The total pressure drop in relation to the valve lift can be calculated from the formula as follows.

"OPD = maximum pressure in the compression area 1 - High pressure in the Design 7 area

396256.8888 - 385180.1489 (pa)

(or)

396.2568888 - 385.1801489 (kpa)

OPD = 11,076.7399 pa (or) 11.0767399 kpa

From the above results, we can conclude that as the valve increases the Pressure value decreases but the total pressure drop from the starting point 1 (i.e. the valve rises 0.001m) point 7 (i.e. for the high valve 0.008m) is 11.0767399 kpa which is the minimum. So on the flow bench, the pressure drop should be minimal.

5.3 Flow Behavior To changes in Valve Geometry:-

Changes in the flow behavior of the valve geometry can be represented from the cartoon of the cut structure and the flow trajectories as shown below.

At each valve height, the animation scheme scheme represents the flow character.

https://youtu.be/IKbfz4ogLNw

At each valve height, flow trajectories animation represent flow behavior.

https://youtu.be/xEk4D13ZCr4

In the upper animation of the fixed structure and flow trajectories in relation to the valve lift, the blue circuit indicates the minimum speed at a certain point above the valve while the red circuit indicates the maximum speed. And in the inlet port, the color that changes from blue to green as the valve is raised indicates an increase in speed.

Reference:-

https://en.wikipedia.org/wiki/Air_flow_bench
https://www.youtube.com/watch?v=l04OPFeqfPY&t=100s

The flow of report:-

1. Objective.
2. Basic.
3. Procedure.
4. Simulation and Analysis.
5. Result and conclusion.