Investigation on the spray characteristics of standard gasoline, n-pentane, iso-octane and ethnaol with a novel heated tip SIDI injector

摘要

The present study was conducted to investigate the effects of thermal and fuel properties on the spray characteristics of a novel heated tip SIDI injector, and explore a new fuel injection method which can be widely used. The novel heated tip injector with an inner heater was re-designed in a conventional multi-hole SIDI injector. The heat generation was combined with the injection driver to control the injection and heating. The temperature of the heater and solenoid coil were controlled with a thermostatic system and the transfer of thermal energy to the fuel combined with the sub-atmospheric pressures were observed experimentally. The sprays from an asymmetric multi-hole SIDI injector were systematically investigated utilizing a high-speed Mie scattering imaging system and a Phase Doppler Particle Analyzer (PDPA) system. The macroscopic spray formations and SMD of standard gasoline, n-pentane, iso-octane and ethanol were measured and compared under different conditions. The influences of temperature, fuel properties and ambient pressure on the formation of macroscopic sprays were evaluated. The results indicate that there are to key factors that affect the spray characteristics under the same ambient pressure, one is the physical properties and the other is fuel temperature. The spray characteristics is the core role which has a high sensitive effect on the engine performances, therefore causes the flexible fuels cannot be widely used because of the limitation of the engine configuration. The aims of this investigation is to explore a new method which analyzes the change trends of the spray characteristics of different fuels on a novel heated tip SIDI injector. And then calibrate the spray characteristics under different conditions through adjusting the superheated degree of the flexible fuels to improve the spray characteristics so as to meet the demands of the engines. (C) 2016 Published by Elsevier Ltd.