1. Air Flow Management in Automotive Prime Movers
P M V Subbarao
Professor
Mechanical Engineering Department
Efficient & Reliable Inhalation is Essential for Healthy Operation of Engine….

2. Selection of Mixture Strength
Air Standard Model
Fuel-air Model
Actual Performance curve

3. Selection of Mixture Strength
Air Standard Model
Fuel-air Model
Actual Performance curve

4. Selection of Sufficient Air : Running Cost Vs Capital Cost

5. Analysis of Intake Process
FUEL A I R
SI Engine
CI Engine

6. Analysis of Intake Process : Current SI Engine
FUEL

7. Analysis of Intake Process : Current CI Engine

8. Hardware for Air Intake
Valve/Port Design 1. Poppet Valve 2. Rotary Valve 3. Reed Valve 4. Piston Controlled Porting Valve Location 1. The T-head 2. The L-head 3. The F-head 4. The I-head: (i) Over head Valve (OHV) (ii) Over head Cam (OHC)

9. Outline of A Modern Engine Intake Port

10. Enhanced Flow Area due to Twin valves

11. Enhancement of Intake Flow Area using Twin Valves

12. Structure of Hardware for Air Intake
Over head Valve (OHV)
Over head Cam (OHC)

13. Poppet Valve & Air Passage

14. Geometrical Nomenclature for Valves
The instantaneous valve flow area depends on valve lift and the geometrical details of the valve head, seat and stem.
There are three separate stages to the flow area development as valve lift increases.

15. Geometrical Shape of Intake Flow Area
For lower valve lift the minimum area is the valve curtain area.
For larger lifts the minimum area is the valve seat area.

16. Shape of A Stream Tube Passing thru Valve Gap

17. Creative Valve Geometries