EFFECTS OF CHARGE STRATIFICATION, AND. CARBURETION OF VOLATILE FUELS ON PERFORMANCE OF CI ENGINE

Abstract

The work was undertaken with the intention of using C.I. engine to produce stratified charge by injecting petrol and other volatile fuels and igniting them with spark. The experiment was performed without first altering the CR of the engine. The performance with petrol, isooctane and benzol injection is discussed. It was found that the engine works smoothly with these fuels at intake air pressures ranging from 0+2 to 0.4 atmosphere. The wor'-.ing of the engine was found to be erratic from 0.4 to 0.7 atm.; and at suction pressures beyond 0.7 atm., the engine stopped. Later, the CR of the engine was reduced from 18.2 to 8.35 and the experiment was repeated. The performance was found to be adversely affected. However, the engine worked smoothly at the suction pressures now ranging from 0.25 atm. to 0.7 atm. irthermore , the work was extended to have an idea of the performance of the some engine by carburetting at full open throttle$ isooctane or petrol and t niting this charge by injec- ting a fixed quantity of diesel, fuel. The performance with the carburetion of isooctane and petrol is discussed. The significant point to note was the power boost of nearly 25% obtained with the carburetion of isooctane, the fixed quantity of diesel oil injected being 80% of the normal full load diesel consumption. Knocking was predominant with the carburetion of petrol. This is discussed and the conclusion was drawn that higher the octane number of the fuel larger the quantity carburetted without causing knock in the engine.