Analysis of hydrodynamic characteristics of sprays of nozzles of ICE

Abstract

The automotive and tractor machinery plays an important role in technical support of agro-industrial complex at the present stage of development of agricultural production. The main energy source of these vehicles are internal combustion engines, which work is influenced highly by spraying nozzles. A comprehensive study of the qualitative indicators of their functioning allowed authors to find new practical and theoretical solutions. In the study of the hydrodynamic characteristics of spraying nozzles, a theoretical analysis was used. When replacing bayonet sprinklers in the vortex chamber diesel with multi-jet, the hydrodynamic parameters of the fuel injection process were performed. Three types of sprays were tested. The studied sprayers differ from each other in the size of a flow section, mass of a needle, the sizes and a location the holes. It causes various sizes of delivery pressure of fuel, an oscillation frequency of a needle of the sprayer and other parameters. The received calculated dependences show that with increase in a flow section with a constant residual pressure critical pressure of a wave of supply of fuel increases. So with a residual pressure of 3 MPas critical pressure of a wave makes respectively 10, 14,4, 16,7 MPas for sprays of three types. Increase in residual pressure causes increase in critical pressure of a supply wave. Due to the need of increase in critical pressure of a fuel supply wave for multiple-jet sprayers (in comparison with bayonet) we will consider influence of the nozzle spring tension pressure on the needle opening delay time. Results of calculation of delay of opening of a needle of a nozzle for bayonet and multiple-jet sprays are presented. Studies show that the size of delay of raising of a needle of a nozzle with the multiple-jet spray with a pressure of the beginning of injection Pz = 15 mpa is closest to delay size for the bayonet spray. The result revealed that the frequency of natural oscillations and their duration slightly differ from each other (no more than 5 %). Hence it can be assumed that the use of the experimental sprayers will not exert the considerable impact on operation of sprayers from the point of view of vibration characteristics.