Although dual-fuel (DF) engines using a low cetane number primary fuel such
as natural gas (NG) ignited by a pilot diesel spray have been the subject
of much investigation over years, there are still many unknown problems rel
ated to the fundamental combustion process of two fuels. In this work, a qu
iescent constant volume combustion bomb and a 3-D numerical model have been
used to study the effects of injection nozzle characteristics on the combu
stion of pre-mixed NG/air with pilot distillate spray. Experimental tests w
ere conducted on combustion process of pre-mixed natural gas/air with pilot
injection pressure of 30 and 20 MPa with a 4 hole injector, and also with
injector nozzle of 8 and 4 holes. The global results obtained from computat
ions compared well with the experimental results. Copyright (C) 1999 John W
iley & Sons, Ltd.