Gas Flow Studies in Direct Injection Diesel Engines with Re-Entrant Combustion Chambers

The paper describes an investigation of the gas flow inside the cylinders of motored direct injection diesel engines using fixed and moving hot wire probes. Particular attention has been paid to the transfer of swirl into the bowl as the piston approaches the end of the compression stroke and the flow pattern in the bowl around T.D.C. The investigation covered two types of bowl in current use, one a toroidal design and the other a re-entrant shape which had been found to give low emissions. Measurements were also made in a re-entrant chamber of simplified geometry with the object of providing data for use in the theoretical modelling of gas flow and combustion processes.