The experimental setup used for the study is briefly described here, and has been explained in more detail in an earlier work [6]. It consists of a low-pressure 4-hole gasoline injector (Fig. 1), typical of injectors used currently in port fuel injection engines. The fuel is pressurized by means of compressed nitrogen, and transducers measure the fuel temperature and the fuel line pressure close to the injector. The injector is actuated by means of an electronic circuit, and the timing of the injection pulse and the pulse duration are controlled by means of a computer with a LaVision programmable timing unit. A schematic of the setup used is shown in Fig. 2. The fuel was sprayed into the ambient (pressure of 0.9 bar and temperature 25 C). The spray from the injector was characterized by optical techniques, as described in the following section.