Effects of heated ethanol on retrofit single-hole gasoline injector performance

The main aim of this work is to explore the injector performance in terms of fuel mass flow rate and discharge coefficient when ethanol is in use with gasoline injectors at elevated temperatures. The operating fuel injection was at the pressures between 0.2 and 0.4 MPa and the temperatures in a range of 40-80 °C. A fuel injector test cell with electronic control for injection pulse, timing and pressure was set to 120 Hz and 60 min injection duration to drive three single-hole 0.34 mm nozzle diameter injectors. The fuels were injected into a known volume flask at quiescence atmospheric pressure and weighed to attain the fuel mass flow rates. By this manner, the discharge coefficient can be calculated by the assumptions of quasi steady, incompressible and one dimensional flow through each injector. When operating at 40 °C injection temperature, ethanol delivered greater fuel amounts than gasoline resulting in higher discharge coefficients. The temperatures of the injected fuels are shown to affect the fuel flow rates and the discharge coefficients.