Modelling and simulation of flow through a flowbench Using SOLIDWORKS

Objective

This project aims to design a flowbench with an inlet valve and a port and the analysis is two-fold.

1. Performance of a parametric test for the grid dependence of the analysis.
2. Once the best grid id decided, analyzing the flow characteristics under various valve lifts with that grid.

1 Introduction

A 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. It is used primarily for testing the intake and exhaust ports of cylinder heads of internal combustion engines.

Grid dependency test is the analysis of a model under the same conditions with different mesh refinement. This test obtains the ideal grid refinement number for the simulation.

In this project, an approximate helical intake port has been modeled, and flow analysis has been done with ethanol as the fluid. The flow velocity is constant for all the alternates with varying valve lift.

2. Geometry and Dimension

i. Geometry of the Flowbench

ii. Dimension of the valve lift

3. PARAMETERS FOR BASELINE SIMULATION

3.1 Output

• Baseline Simulation plots.

Fig. 3. Velocity Plot Fig. 4. Pressure Plot

• Mass Flow Rate

Fig. 5. MAss flow rate

4. GRID DEPENDENCY TEST

Parameters for Grid dependence test

4.1 New parametric study- Grid dependence test

In order to select the level of refinement, we run a parametric test where for constant valve lift of 0.003m we set three different grid sizes ranging from 4 to 6. Also, we check the Velocity and Pressure plots for these three values.

Note: Level of refinement of these plots is 255.

4.2 Output: Results after the study

i. Grid Size 4

• Velocity Plot @ valve lift 0.003m

• Pressure Plot @ valve lift 0.003m

ii. Grid Size 5

• Velocity Plot @ valve lift 0.003m

• Pressure Plot @ valve lift 0.003m

iii. Grid Size 6

• Velocity Plot @ valve lift 0.003m

• Pressure Plot @ valve lift 0.003m

• SG Mass Flow Rate

• Results and Observation

1. From the graph, we can see that as the refinement level increases mass flow rate magnitude also get more optimum.
2. There are no subsequent changes in pressure plots.
3. But in the Velocity plot, when the fluid enters the combustion chamber for different grid sizes the velocity pattern is considerably changing.
4. With the grid size of 5, we observe a pattern that can be said to be the Swirl of the fluid that happens inside the cylinder. Hence for proper results and plot description, we go with grid size 5. Although, we may go for a higher value but that may increase the computation time as well.

5. VALVE LIFT TEST

5.1 Parameters for Valve Lift Test

With a grid size of 5, now we run another parametric study where we change the valve lift from 0.001m to 0.008m with 8 intervals, rest other parameters are kept same one change that is made is we add a local mesh around the valve so as to get better results. In this study we're looking for the Velocity and Pressure plots, Mass flow rates for different valve lifts, Flow trajectories, etc.

5.2 Results Of Parametric study of valve lift

a. Valve lift at 0.001m

• Velocity Plot @ Mesh Size 5

• Pressure Plot @ Mesh size 5

• Velocity Trajectory of Valve Lift at 0.001m

b. Valve lift at 0.002m

• Velocity Plot @ Mesh Size 5

• Pressure Plot @ Mesh size 5

• Velocity Trajectory of Valve Lift at 0.002m

c. Valve lift at 0.003m

• Velocity Plot @ Mesh Size 5

• Pressure Plot @ Mesh size 5

• Velocity Trajectory of Valve Lift at 0.003m

d. Valve lift at 0.004m

• Velocity Plot @ Mesh Size 5

• Pressure Plot @ Mesh size 5

• Velocity Trajectory of Valve Lift at 0.004m

e. Valve lift at 0.005m

• Velocity Plot @ Mesh Size 5

• Pressure Plot @ Mesh size 5

• Velocity Trajectory of Valve Lift at 0.005m

f. Valve lift at 0.006m

• Velocity Plot @ Mesh Size 5

• Pressure Plot @ Mesh size 5

• Velocity Trajectory of Valve Lift at 0.006m

g. Valve lift at 0.007m

• Velocity Plot @ Mesh Size 5

• Pressure Plot @ Mesh size 5

• Trajectory of Valve Lift at 0.007m

h. Valve lift at 0.008m

• Velocity Plot @ Mesh Size 5

• Pressure Plot @ Mesh size 5

• Trajectory of Valve Lift at 0.008m

5.3. Graph

The plot of Valve lift vs Mass flow rate

Conclusions

As clearly seen from the cut plots the velocity of flow increases as the valve lift increases. This can be observed by the increase in green and red areas in the cut plots as the lift increases

As clearly seen from the cut plots the pressure reduces as the valve lift increases.This can be observed by the reduction in red areas in the cut plot as the lift increases.

The mass flow rate increases as the valve lift increases.