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….

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.

The Biological Pulse : A Thermodynamic Property species heart rate (beats per minute) cat 120-170 dog 70-120 ferret 200-400 guinea pig 240-310 horse 28-40 rabbit 120-150

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.

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

Formula Car Weight : 400 kg Speed : 18000 rpm

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

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

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.

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.

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

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

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

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

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

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

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

Conceptual illustration of general EV configuration

A Faraday Future FF 91 electric car FF91 is displayed on stage during an unveiling event at CES in Las Vegas, Nevada January 3, 2017. REUTERS/Steve Marcus

Hybrid vehicle

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 53kW @ 4500rpm Engine Max. Torque 115Nm @ 4200rpm

Pune Urban Drive Cycle

Cumulative Kinetic Energy Wastage by Vehicle per Driving Cycle 42382.8 79296.9 22501.6 53078.1 9407.5 35019.5 2538.6 36748.7 4921.9 11812.9 29754.2 179702.1 29393.3 145894.5 9071.9 148095.7 97748.6 179691.7 18132.9 21710.0 1204149.7 1204.1kJ