Internal flow analysis of nozzles for DI diesel engines using a cavitation model

A three-dimensional viscous flow analysis method using a cavitation model was applied to run internal flow calculations for the fuel injector nozzles of direct-injection diesel engines. It is especially notable that this method made it possible to examine and clarify the mechanism producing an asymmetrical spray from the valve covered orifice type nozzle under a small lift condition with an eccentric needle position. The calculated results for cavitation were compared with experimental data obtained by using a transparent model scaled up fivefold, and good qualitative agreement was seen between the two sets of data.