Spray Characteristics of Local-Contact Microwave-Heating Injector Fueled with Ethanol 2013-32-9126

A microwave-heating system is integrated in a port-injector to minimize the cold-start problems and exhaust emissions of engine. This paper report the experimental investigations of spray characteristics and numerical simulation of fuel temperature inside port-injector. Fuel flow inside port-injector is heated using microwave-heating and this system is called “local-contact microwave-heating injector” (LMI). LMI can be used to increase temperature of ethanol near boiling point (351.5K) before injected into room temperature. Injection pressure of fuel was operated constant at 0.3MPa. Characteristics of fuel spray were observed experimentally using high speed camera, CMOS camera and LDSA. Numerical simulation was conducted to verify the effect of local heating on spray distribution. 2-D geometry of injector with finer quadrilateral mesh (56,000 meshes) was solved numerically on pressure based solver in CFD simulation code. Conservation equations of mass, momentum and energy were modelled on time dependent using Pressure-Implicit with Splitting of Operation (PISO) algorithm. The result shows good agreement between numerical and experimental measurement of temperature distribution. An increasing of fuel temperature inside port injector is considerably improving Sauter Mean Diameter (SMD) of ethanol spray. Pre-heating fuel system by LMI can improve spray quality and leads to possibly being used at port injection engine.