Development of Hardware to Generate Homogeneous Mixtures in

Development of Hardware to Generate Homogeneous Mixtures in S. I. I. C. Engines P M V Subbarao Professor Mechanical Engineering Department A Baby Care Engineering for A Quick & Comprehensive Phenomenon…. . .

Development of Combustion Science for Eco-friendly SI Engines Best Power Closed Loop Control Best fuel Economy HC emissions NOx emissions CO emissions

The Role of Fuel Induction System • The tasks of the fuel induction systems are; • to introduce right amount of fuel @ 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.

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

Thermo-flow Model for Carburetor 1

The Trajectories of Droplets Travelling in Manifolds

Evaporation of Droplets Basic Mechanism : Convective Heat and Mass Transfer The heat and mass transfer processes during droplet evaporation are to predicted by suitable models.

Models of Droplet Evaporation • • • Model may assume: Spherical symmetry of the droplet. The presence of a quasi-steady gas film around the droplet. Uniform temperature within the droplet. Liquid-vapour thermal equilibrium on the droplet surface. Under these conditions, the rate of temperature change is determined by the energy balance.

Droplet evaporation • The droplet evaporation rate is given by where DAB the gas diffusivity, Sh* the non-dimensional Sherwood number, and Bm the mass transfer number. The mass transfer number BM is equal to: where Yfs and Yf are the mass fraction of vapor fuel at the droplet surface and the surrounding

Fuel Evaporation in Engine Cylinder & Manifolds

Development of Combustion Science for Eco-friendly SI Engines Best Power Best fuel Economy HC emissions NOx emissions CO emissions

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.