1. P M V Subbarao Professor Mechanical Engineering Department
20th Century Inventions for Automotive Prime Movers based on Otto’s Model
P M V Subbarao
Professor
Mechanical Engineering Department
Methods of Building a Powerful Artificial Horse….

2. Thermodynamic Design : A tradition of Post Carnot Research
The operation of any engine is a cyclic process.
Major portion of motive power generation occurs in any Reciprocating engine during closed cycle.
Named as control mass/closed system.
Engines can have External or Internal Combustion.
An engine operation is a transient process which gets completed in a known or required Cycle time.
Lowering of the Cycle time will lead to higher the speed of the engine.
Needs many models for each process/event in a cycle.
A sustainable model demands selection of a cycle & cycle time.

3. The Biological Pulse : A Thermodynamic Property
species
heart rate
(beats per minute)
cat
dog
70-120
ferret
guinea pig
horse
28-40
rabbit

4. The world’s biggest engine : Wärtsilä-Sulzer RTA96. :May 2015
14-cylinder, 2-stroke turbocharged diesel engine.
Weight : 2.3 million kgs
Speed : 102 rpm
powering the Emma Maersk
It has now become cheaper to transport goods from China to a US port than to transport the same goods from a US port to the final destination inland of US by a truck.

5. The Elephant
Weight : 4000 – 7000kg
Heart Pulse : 28 per minute

6. Formula Car
Weight : 400 kg
Speed : rpm

7. The Cheetah Speed :112–120 km/h Weight ~ 65kg
Heart Pulse ~ 170 per minute

8. Various Sustainable Cycles of Nature
Water Cycles
Energy Cycles
Life Cycles of Animals
Life Cycles of Plants
Seasonal Cycles
Planetary Cycles
Rock Cycles
Geo-Physical Cycles
Chemical Cycles
Disease Cycles

9. The Otto’s Artificial Horse
Nicolaus Ottowas's first occupation was as a traveling salesman selling tea, coffee, and sugar.
He soon developed an interest in the new technologies of the day and began experimenting with building four-stroke engines.
After meeting Eugen Langen, a technician and owner of a sugar factory, Otto quit his job, and in 1864, the duo started the world's first engine manufacturing company N.A. Otto & Cie (now DEUTZ AG, Köln).
In 1867, the pair were awarded a Gold Medal at the Paris World Exhibition for their atmospheric gas engine built a year earlier.

10. Why road steam disappeared
By 1921, steam tractors had demonstrated clear economic advantages over horse power for heavy hauling and short journeys.
However, petrol lorries were starting to show better efficiency and could be purchased cheaply as war surplus.
On a busy route a 3-ton petrol lorry could save about £100 per month compared to its steam equivalent, in spite of restrictive speed limits, and relatively high fuel prices and maintenance costs.
Road steam disappeared through becoming uneconomical to operate.

11. Otto’s Engine Cycle vs Otto’s Thermodynamic Model
Intake
Stroke
FUEL
Ignition
Power
Stroke
Combustion
Products
Exhaust
Stroke
Fuel/Air
Mixture
Compression
Stroke
Actual
Engine Cycle TC
Qin
Const volume
heat addition
Process
Qout BC
Const volume
heat rejection
Process
Air
Compression
Process
Expansion
Process
Thermodynamic Model
Cycle

12. Air-Standard Otto cycle
Process 1 2 Isentropic compression
Process 2  3 Constant volume heat addition
Process 3  4 Isentropic expansion
Process 4  1 Constant volume heat rejection
Compression ratio:
Qin
Qout v2 TC v1 BC TC BC

13. Effect of Compression Ratio on Thermal Efficiency
Ignition
Power
Stroke
Present SI engines
7 < r < 11
k = 1.4
Spark ignition engine compression ratio limited by T3 (auto-ignition) and P3 (material strength), both ~rk
For r = 8 the efficiency is 56% which is twice the actual indicated value

14. Otto’s Artificial Animal : Carburetted S I Engines
Carburetted SI- IC Engines.
High Specific Power
Cleaner exhaust compared to Steam Engine
Low Fuel Economy  Throttling, quantity governed

15. Current SI Engines MPFI Engines High Specific Power
Fuel economy better than carbureted  Quality governing, no throttling
High HC emissions during transient operation
Limited improvement at part load

16. 21st Century SI Religion Engines
DISI Engines
High power at full load  Homogeneous charge, high CR, high vol.
High Fuel economy  Distinctly stratified charge, avoidance of throttling losses, quality governing
Lower HC compared to MPFI

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

18. Conceptual illustration of general EV configuration

19. A Faraday Future FF 91 electric car
FF91 is displayed on stage during an unveiling event at CES in Las Vegas, Nevada January 3, REUTERS/Steve Marcus

20. Hybrid vehicle

21. 2003 Toyota Prius Ni-MH battery: 273.6V (228 cells@1.2V), 52 MPG
Curb Weight
1220 kg
Battery
21kW, 274V, 6.5Ah
Motor Generator
33kW
Engine Max. Power
4500rpm
Engine Max. Torque
4200rpm

22. Pune Urban Drive Cycle

23. Cumulative Kinetic Energy Wastage by Vehicle per Driving Cycle
9407.5
2538.6
4921.9
9071.9
1204.1kJ