Abstract
KEYWORDS
Car, carburettor engine, working parameters, analytical dependencies
ABSTRACT
The paper deals with a analytical study of the air inlet for the carburettor engines with practical applications in the design and working of these, concerning the necessary air flow rate, the depression in the carburettor diffuser, the volumetric flow rate of the consumed gas, the coefficient of admission. There are taking into consideration the head losses and the hydraulic inertia of the aspiration duct characterised by the intensity and propagation time of the depressive waves. The proposed equations are emphasising the analytical dependencies between the working parameters, constructive and characteristic quantity as: cylinder capacity, carburettor size, engine speed, the air and gasoline densities, the coefficient of load, the mass ratio of air/gasoline optimum combustion, coefficients of local hydraulic losses, Coriolis’s, Chézy and Reynolds’s coefficients. Also, the influence of the other physical properties (elasticity/compressibility, viscosity) of the involved fluids is analysed. The study is illustrated by a numerical example, having as model a basic scheme of a SOLEX carburettor with descending air stream.