1. Transient Power of A Vehicle
P M V Subbarao
Professor
Mechanical Engineering Department
Matching of Transient Horse to TransientCar….

2. Total Vehicular Resistance at Constant Velocity
  AR = air resistance [N]
RR = rolling resistance [N]
            GR = gradient resistance [N]
TR = total resistance [N]
           

3. Urban Drive Cycle

4. Transient Nature of I.C. Engine

5. Instantaneous Engine Cylinder Volume

6. Generation of Primary Dynamic Forces

7. Inertial or Transient Forces on Vehicle
Transient forces are primarily comprised of acceleration related forces where a change in velocity is required.
These include:
The rotational inertia requirements (FI ) and
The translational mass (Fma).
If rotational mass is added to a translating vehicle, it adds not only rotational inertia but also translational inertia.

8. Inertial Resistance of A Vehicle
where:
FIR = inertia resistance [N]        
meff-vehicle = Vehicle mass + Equivalent mass of rotating parts [kg]
mvehicle = Vehicle mass [kg]
meq = Equivalent mass of rotating parts [kg]
a = car acceleration [m/s2],
(from 0 to 100 km/h in: 6 s (4.63 m/s2), 18 s (1.543 m/s2))

9. Equivalent Mass of Rotating Parts
Torque due to any rotating part (ex. Wheel)
= angular acceleration k = radius of gyration
Typical Distribution of Polar Inertia : wheels and axles = 78% , propeller shaft = 1.5%, Engine = 6%, Flywheel and clutch =14.5%

10. Equivalent Mass of All Rotating Parts
Therefore the equivalent mass of all rotational parts including losses is represented as:

11. Required Torque & Power at Wheels
InstantaneousTractive Effort demanded by a vehicle):

12. Model for Prediction of Instantaneous Fuel Consumption & Emissions
Vehicle Resistance Model

13. Engine Model

14. Multi Cylinder Engine Torque

15. Pune Urban Drive Cycle

16. Engine RPM during Urban Driving Cycle
Time, sec

17. MPFI-SI Engine Fuel Consumption

18. If Engine Idles during Breaking

19. Fuel Savings due to Idling Logic
MECH 435

20. Idling Engine During Braking : Fuel Consumption

21. Engine Model

22. First Law Analysis: USUF
FUEL A I R
SI Engine
CI Engine
Intake Process:

23. Current SI Engine & Future CI EngineA I R
FUEL
Current CI Engine & Future SI Engine