19th & Early 20th Century SI Models for Automotive Prime Mover P M V Subbarao Professor Mechanical Engineering Department Zero to First Generation Technologies for Artificial Horse…..

Cyclic Work To be Delivered by An Artificial Horse Ideal cycle work to be provided by A Powering Engine: The speed of the engine for a given vehicle speed in km/h is: Time available for completion of a cycle (Four stroke Model for Engine):

Cyclic Work To be Delivered by An Artificial Horse Ideal cycle work to be provided by A Powering Engine:

Carnot’s Further Recommendations for Ideal Gas Engine 1824: Sadi Carnot, who founded the science of thermodynamics, identified several fundamental ideas that would be incorporated in later internal combustion engines: He noted that air compressed by a ratio of 15 to 1 would be hot enough (200°C) to ignite dry wood. He recommended compressing the air before combustion. Fuel could then be added by "an easily invented injector". Carnot realized that the cylinder walls would require cooling to permit continuous operation. Later, Diesel thought he could avoid this, but found out the hard way. He noted that usable heat would be available in the exhaust, and recommended passing it under a water boiler.

History of Otto’s Engine The Otto/Langen atmospheric engine ran at 12% efficiency and produced .5 hp (0.37 kW) at 80 RPM. The atmospheric engine used a gas flame ignition system and was made in output sizes from 0.25 to 3 hp (0.19 to 2.24 kW). After 14 years of research and development Otto succeeded in creating the compressed charge internal combustion engine May 9, 1876. In a few years after the Otto engine was developed engine power rose until it reached 1000 hp. The Otto Cycle engine was eventually adopted to run on Ligroin and eventually gasoline, and many gases.

Reciprocating Engine Kinematic Chain Instantaneous Piston Displacement:

Engine Geometric Ratios Engine Compression Ratio Cylinder Bore-to-Stroke Ratio Kinematic Rod Ratio

The Geometrical Description of Engine Cylinder

Instantaneous non-dimensional Displacement Volume Rod ratio

Instantaneous Cylinder Volume : Dynamic Cylinder Volume

Instantaneous Thermodynamic Parameters

Engine Geometric Ratios Engine Compression Ratio Cylinder Bore-to-Stroke Ratio Kinematic Rod Ratio

Artificial Ignition of Fuel-air Mixture Edmond Berger invented an early spark plug on February 2, 1839. In 1860 Étienne Lenoir used an electric spark plug in his gas engine, the first internal combustion piston engine and is generally credited with the invention of the spark plug. 1861 – 1886 : 1876 The four-stroke engine which is acknowledged as the "Otto" cycle engine. 1886: The Otto is one of the first successful person to use a spark plug.

Clue to Achieve Higher Efficiency

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

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 958cc!!! The Mercedes 35 HP (German: Mercedes 35 PS) was a radical early car model designed in 1901. Engine volume: 5,918CC. The racecar was of a disappointing performance by multiple technical complications and enduring just for few laps.

SI Engine for Propulsion The phenomenon of detonation was first observed and described by Harry Ricardo during experiments carried out between 1916 and 1919 to discover the reason for failures in aircraft engines.

Thermo-chemical Feasibility of Otto’s Model

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

Pure Octane & Critical Compression Ratio In 1921, automotive engineers working for General Motors discovered that tetraethyl lead (better known as lead) provided octane to gasoline, preventing engine knock. Formula Name Critical r CH4 Methane 12.6 C3H8 Propane 12.2