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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.

An experimental study has been conducted at small kerosene droplet behavior near well-defined butane diffusion flame for the critical need on high efficient and cleaner energy technology. High temperature of background gas was generated using butane flame. Microflame from butane can reach the maximum temperature around 1200K at tip of outer glass. Single droplet of kerosene was injected by a small injector tube (30 μm-diameter) in to hot environment. Droplet of kerosene was released by attachment of piezo actuator on wall injector. Once the droplet is exposed to the hot atmosphere of micro flame, the temporal regression of the droplet surface was recorded. Droplet diameter was observed by CCD camera with strobe light flash at 180ns. The images captured in this experiment were analyzed by post-processing software to determine the vaporization of droplet.

In this study, the background gas of the droplet vaporization was concerned and simulated numerically using ANSYS fluent code. The new type, engine-like, condition of high pressure chamber and high temperature environment was considered to conduct experiment on kerosene droplet evaporation. 2D geometry of domain simulation was discretized in the very fine quadrilateral meshes. The numerical approach was solved using implicit scheme of compressible gas solver (density based). Temperature dependent properties of air are expressed for gas material properties. As the study concerning on high pressure condition the equation state of Peng-Robinson was expressed in simulation. Governing equations of mass, momentum and energy were solved by the second order upwind for flow, turbulent kinetic energy and turbulent dissipation rate. Standard k-ε model was used to solve turbulence flow in the spatial discretization.