The Effect of Boundary Conditions on the Downstream Penetration of Pulsed Sprays After Impaction on a Flat Surface

Abstract

An experimental study has been conducted of the wall sprays produced afer impaction on a j a t surface by the pulsed sprayfrom a single hole nozzle. The experiments are of relevance to direct injection diesel engines and they extend the range of boundary conditions covered in previous work, with variation of gas density, spray wall angle, gas cross-Jlow velocity and cross-Jlow turbulence level. The initial and boundary conditions are documented to provide a database which is suitable for computational Puid dynamics (CFD) model validation of an important aspect of diesel engine in-chamber Jlow. Previous work in the area is described and published empirical correlations are reviewed. The measurements of wall spray penetration as a function of time are presented and described and a correlation equation is proposed whichJits the data with good accuracy.diesel engines, sprays, fuel injectors, wall impaction NOTATION gation of the characteristics of diesel fuel sprays. J . Mech. Engng SOC., Japan, 1980,15,57-64. Coghe, A. and Cossali, G. E. Experimental analysis of wall-spray structure by laser-Doppler techniques. Proc. ILASS-92, 1992, 97-103 (Shell, Amsterdam). 2~10, J. R. and Cbigier, N. Impinging diesel spray dynamics. Atomization and Sprays, 1991,1,303-318. Yule, A. J. and Awl, S. M. Cyclic variations in diesel sprays. Fuel J., 1 9 8 9 , s 1558-1564. Mum, M. R. Studies of diesel sprays with cross-flows and solid boundaries. PhD thesis, sprays produced by a diesel injector: further details of spray structure. To be submitted to Roc. Instn Mech. Engrs, Part D.