1. Present & Future Models for Automotive Prime Movers
P M V Subbarao
Professor
Mechanical Engineering Department
Better Structure of an Artificial Horse to Mimic a Horse…

2. The Reference
Target: may Engine must be many times a Horse

3. Anatomy of an Artificial Horse for Busy Roads ???

4. The Biological Measure of Intelligence
Species
Simple brain-to body ratio (E:S)[1]
small ants
1:7[2]
tree shrew
1:10
small birds
1:14
human
1:40
mouse
cat
1:110
dog
1:125
squirrel
1:150
frog
1:172
lion
1:550
elephant
1:560
horse
1:600
shark
1:2496
hippopotamus
1:2789

5. Evolution of Intelligent Species : Natural Engine

6. Future Trends : Road fuel use and CO2 by vehicle type

7. The Great Power Train Race

8. The Type of Prime Mover for Light Vehicle Sales in Two Decades

9. Why I.C. Engines in 21st Century?
Electric vehicles (EVs)
Batteries are heavy ≈ 120/kg of gasoline equivalent
Fuel cells better, but still nowhere near gasoline
"Zero emissions" myth - EVs export pollution
Environmental cost of battery materials

10. The Concept of Green Car
In any case, all-electric cars are green only if the electricity to recharge them is generated in low-carbon ways.
In nuclear-powered France the electricity to drive a battery car one kilometre causes carbon-dioxide emissions of just 8g.
Yet in China and India, which generate much of their electricity from coal, those emissions are over 120g.
It would be greener to drive a new petrol/Diesel-engined car instead.
Solar Car

11. The Scope for Innovation
All sorts of industries are pumping money into making batteries more efficient and cheaper, but there are no breakthroughs round the corner
Conventionally fuelled cars have been getting more efficient for decades.
A study by Michael Sivak of the University of Michigan found that between 1970 and 2010 the average fuel economy of America’s car fleet improved by 66%.
Now money is being poured into making it even better
A recent survey found that in big emerging markets especially, the motor industry was switching its research funds back to the internal-combustion engine.

12. Future of Car Engines
Car engines are continuing to shrink, but are now being fitted with things like turbochargers and fuel-injection systems that used to be available only on more expensive models.
This means they cost more to make but achieve better mileage without loss of performance.
Other fuel-saving gadgets include “start-stop”, in which the engine cuts out during idling, and various means of storing the energy released by braking.

13. The Art of Down Sizing an Engine

14. Future Targets for Fuel Economy of LCVs

15. Space for innovation in Conventional Concepts - factor of 2 in efficiency
Ideal Otto cycle engine with CR = 8: 52%
Real engine: %
Differences because of
Throttling losses
Heat losses
Friction losses

16. Space for innovation - infinite in pollutants
Pollutants are a non-equilibrium effect
Burn: Fuel + O2 + N2  H2O + CO2 + N2 + CO + UHC + NO
On A Faster Expansion: CO + UHC + NO “frozen” at high level
With slow expansion, no heat loss: CO + UHC + NO H2O + CO2 + N2
But how to slow the expansion and eliminate heat loss?
Worst problems: cold start, transients, old or out-of-tune vehicles .
90% of pollution generated by 10% of vehicles !!!!

17. Space for innovation - very little in power
IC engines are air processors
Fuel takes up little space
Power  Air flow
Limitation on air flow due to
“Choked” flow past intake valves
Frictional losses, mechanical strength - limits RPM
Slow burn
Majority of power is used to overcome air resistance - smaller, more aerodynamic vehicles beneficial

18. Clues for Improvement- alternative fuels : Natural Gas
Somewhat cleaner than gasoline, non-toxic
High octane without refining or additives (≈ 110)
No cold start problem
Half the CO2 emission of EVs charged with coal-generated electricity
Dual-fuel (gasoline + natural gas) easily accommodated
Lower energy storage density (≈ 1/4 gasoline)
Lower power (≈ 7% less)
Attractive for fleet vehicles with limited territory
Renewable bio-methane could increasingly take the place of fossil-fuel gas.
The IC Engine is not addicted to fossil fuels …. WE ARE!

19. Clues for Improvement - alternative fuels – Alcohols/Bio-Diesels
Slightly cleaner than gasoline
High octane (≈ 95)/ varying (48 – 67) Cetane
Not cost-effective without price subsidy
Lower storage density (methanol ≈ 1/2 gasoline)
Toxic combustion products (aldehydes)
Attractive to farm states

20. Clues for Improvement- alternative fuels - Hydrogen
Ultimate clean fuel
Excellent combustion properties
Ideal for fuel cells
Very low storage density (1/10 gasoline)
Need to manufacture - usually from electricity + H2O
Attractive when we have unlimited cheap clean source of electricity and breakthrough in hydrogen storage technology

21. Clues for Improvement- reduce heat loss
Heat losses caused by high engine turbulence level
Need high turbulence to
Wrinkle flame (premixed charge, gasoline)
Disperse fuel droplets (nonpremixed charge, Diesel)
"Inverse-engineer" engine for low-turbulenc
Gasoline - electrically-induced flame wrinkling?
Diesel - electrostatic dispersion of fuel in chamber?

22. Clues for Improvement - reduce throttling loss
Premixed-charge IC engines frequently operated at lower than maximum torque output (throttled conditions)
Throttling adjusts torque output of engines by reducing intake density through decrease in pressure ( P = rRT)
Throttling losses substantial at part load

23. Clues for Improvement for improvements : Reduce Friction Losses
Programmable intake/exhaust valve timing
Electrical/hydraulic valve actuation
Choose open/close timing to optimize power, emissions, efficiency - can eliminate throttling loss

24. Clues for Improvement for improvements : Down Sizing

27. Clues for Improvement : Reduce NOx
Homogeneous ignition engine - controlled knocking
Burn much leaner mixtures - higher efficiency, lower Nox
Need to abandon traditional combustion control strategy

28. Ideas - improved lean-limit operation
Recent experiments & modelling suggest lean-limit rough operation is a chaotic process
Feedback via exhaust gas residual
Could optimize spark timing on a cycle-to-cycle basis
Need to infer state of gas & predict burn time for next cycle - need in-cylinder sensors

30. Conclusions IC engines are the non-ideal form of horse.
Despite over 100 years of evolution, IC engines are far from optimized
Any new idea must consider many factors, e.g.
Where significant gains can & cannot be made
Cost
Resistance of suppliers & consumers to change
Easiest near-term change: natural-gas vehicles for fleet & commuters
Longer-term solutions mostly require improved (cheaper)
Sensors (especially in-cylinder temperature, pressure)
Actuators (especially intake valves)