Fuel Induction to Combustion in I.C. Engines P M V Subbarao Professor Mechanical Engineering Department A Quick but Comprehensive Phenomenon…...

The Role of Fuel Induction System The tasks of the fuel induction systems are; to introduce right amount of specified schedule. –This schedule must be in agreement with allowable Combustion Mechanism. to prepare a mixture that satisfies the requirement of the Combustion Mechanism. –This preparation is to be carried out over entire engine operating regime. –In principle, the optimum air-fuel ratio for an engine is that which give the required power output with the lowest fuel consumption. It should also ensure smooth and reliable operation.

Combustion Mechanisms : Types of Digestion of Diet Artificial Initiation of combustion. –All pre-process should be completed before intiation of combustion. –Digestion succeeds all the preprocess. –Onset of digestion/combustion is through sparking –Pre-mixed digestion/combustion. Natural Initiation of combustion. –Pre-processing of a small fraction of fuel and air initiates the natural ignition. –However, pre-processes in remaining fraction of fuel and air are accelerated after ignition. –Pre-process continue till the end of digestion. –Simultaneous/Diffusive digestion/combustion.

Essential Events in Combustion Processes Pre-processing of fuel an air. The initiation & stabilization of reaction. Execution and completion of the reactions. Post reaction events.

Pre-processing of fuel & Air Vs Combustion Mechanism Pre mixing of fuel and airNo Pre mixing of fuel and air Partial Pre mixing of fuel and air

Status of Fuel & Air Before Onset of Combustion

Care for Occurrence of Combustion Occurrence of combustion in SI Engine : A Child Care Event. Occurrence of combustion in CI Engine: A Teen Care Event. CI Engine SI Engine

Type of Fuel Vs Traditional Combustion Strategy Highly volatile with High self Ignition Temperature: Spark Ignition. Ignition after thorough mixing of air and fuel. Less Volatile with low self Ignition Temperature: Compression Ignition, Almost simultaneous mixing & Ignition.

Types of Fuel Induction Systems : SI Engines The fuel Induction systems used in SI engine are classified as: –Carburetors. –Throttle body Fuel Injection Systems. –Multi Point Fuel Injection Systems. –Direct Gasoline Injection System

Evolution of Fuel Inductions Systems : SI Engines – First Generation

Evolution of Fuel Inductions Systems : SI Engines – Second Generation

Evolution of Fuel Inductions Systems : Third Generation

Evolution of Fuel Inductions Systems : Next Generation

Carbureted S.I. Engines There are some very obscure auto makers, primarily in Africa and Russia, who still build cars with carburetors. These cars are typically designs that have been purchased from their original manufacturers and remade for a new market. To keep expenses down, these auto makers avoid computer controls and use mechanical components such as a carburetor on their cars to make them more easily repairable. Many motorcycles, are one of the last holdouts of the factory production carburetors today.

Jul 31, 2006 : New motorbike technology bids goodbye to the carburettor On June 26, Hero Honda, for the first time in India, launched the fuel injection (FI) technology in two-wheelers under the brand name Glamour FI.

Air-Fuel Supply Systems : Carbureted S.I. Engines

Thermo-flow Model for Carburetor 1