Helical Port Flow Simulation

Introduction :

The port geometry represents that helical port found in the diesel engine, its used to produce necessary swirl. This swirl is responsible for proper mixing of fuel and hot air. Thus, engine performance is influenced by flow of the air in the the cylinder.

Upon testing 4 grids with different this one found to be most accurate and completed in a practical time.

Setup :

Steady State Simulation

Global Mesh Size - 5

Local Mesh on valve and the passage around the valve of size 2

Boundary Condition : At inlet - Total Pressure - 2 atm ; At outlet - Static Pressure - 0.5 atm

These boundary condition were selected to approximately immitate the pressure conditions during suction stroke of a engine.

Parametric Study :

Input Parameter - distance between valve and cyliner i.e. lift

variation from 0.002 m to 0.01 m with 5 design points.

Output Parameter - Surface Goal - Mass Flow Rate from outlet

Result :

Results were exported to excel from the parameric study as performed.

Goal (Value)	Design Point 1	Design Point 2	Design Point 3	Design Point 4	Design Point 5
D1@[email protected] [m]	0.002	0.004	0.006	0.008	0.01
SG Mass Flow Rate 1 [kg/s]	-0.088606047	-0.12720366	-0.14223326	-0.144862524	-0.146430346

The chart below plots the data presented above, x axis containing values of lift and y axis contains the values of mass flow rate.

Conclusion :

As expected the with the increase in the lift the mass flow rate increases to a point beyond which it doesn\'t increase furthur, when increase further, it will lead to excessive pressure drop.

The mass flow rate is negetive for the reason that, the flow of the fluid is leaving the surface from the outlet which is expected.

The figure below is obtained by inserting \'Flow Trajectories\' in the result\'s drop down menu. The figure clearly shows that swirl is induced in it.