Otto Cycle to Diesel Cycle P M V

Otto Cycle to Diesel Cycle P M V Subbarao Professor Mechanical Engineering Department Creation of Religious Engines…

Clue to Achieve Higher Efficiency

Hardware Feasibility of Otto Cycle Net cycle work: Piston Displacement volume Work done per unit piston displacement volume:

Measure of Size & Feasibility P AIR 3 Qin Wcycle 4 2 1 V 2 V 1

Factors Affecting Work per Cycle The net cycle work of an engine can be increased by either: i) Increasing the r (1 2’) ii) Increase Qin (2 3”) 3’’ P 3’ C (ii) 3 4’’ (i) Qin 2’ Wcycle 2 4 4’ C 1 V 2 V 1

Creation of Compact Engines Using Otto Cycle (200 CC) 2 Qin = 500 J/cycle) 1, 8 MEP, MPa 1, 6 1, 4 1, 2 1 Qin = 200 J/cycle) 0, 8 0, 6 Qin = 100 J/cycle) 0, 4 0, 2 0 0 2 4 6 8 rv 10 12 14 16

The Historical Event in Automobiles • In 1893, the Benz Velo became the world's first inexpensive, mass-produced car. • 12000 unites were produced. • 0. 7 hp and 958 cc!!! • The Mercedes 35 HP (German: Mercedes 35 PS) was a radical early car model designed in 1901. • Engine volume: 5, 918 CC. • The racecar was of a disappointing performance by multiple technical complications and enduring just for few laps.

SI Engine for Propulsion

Thermo-chemical Feasibility Fuel/Air Mixture Compression Stroke

Engine Damage From Severe Knock Damage to the engine is caused by a combination of high temperature and high pressure. Piston crown Cylinder head gasket Aluminum cylinder head

Critical Compression Ratio Formula CH 4 C 3 H 8 C 8 H 18 Name Methane Propane Isooctane Critical r 12. 6 12. 2 7. 3

History of Wildfires 1825 1853 1865 1870 3, 000 acres 482, 000 acres 1, 000 acres 964, 000 acres New Miramichi Fire Killed 160 people. Brunswick Yaquina Fire Oregon Silverton Fire Oregon Worst recorded fire in state's history. Saguenay Fire Quebec 1, 200, 000 1871 Peshtigo Fire acres Killed over 1, 700 people and has distinction of the conflagration that caused the most deaths by fire in Wisconsin United States history. It was overshadowed by the Great Chicago Fire that occurred on the same day.

Generalized Flammability Map

Design Constraints: Flammability Characteristics Rich Mixture Lin e Burning Impossible Flash Point Mixture Temperature Inflammable mist Fla Lean M ix Spontaneous Ignition Flammable Vapour mm ab le mis t Stoichiometric Line

Inflammability of Fuels

Spontaneous (Auto) Ignition Temperature of Fules Fuel SIT, C Petrol 246 -- 280 Diesel 210 Kerosene 295 Natural Gas 580 Hydrogen 500 Iso-Octane 447 Iso-Butane 462

Rudolf Christian Karl Diesel • Diesel published a treatise entitled, Theory and Construction of a Rational Heatengine to Replace the Steam Engine and Combustion Engines Known Today. • This formed the basis for his work on and invention of, the diesel engine. • In his engine, fuel was injected at the end of compression and the fuel was ignited by the high temperature resulting from compression.