Abstract: The cavitation flow inside injector nozzle of microemulsificated biomass fuel is numerically simulated by using homogeneous mixture flow model plus full cavitation model. The rationality of the models is verified by WINKLHOFER’s test case. Two different nozzles with sharp and round inlets are selected to describe the influence of orifice inlet on the cavitation flow, and the results are compared with those of 0# diesel fuel. The dimensionless numbers such as the Reynolds number (Re), cavitation number (K), Weber parameter (We), and discharge coefficient (Cd) are introduced to analyze the internal flow characteristics. The results show that the change pattern of injection mass flow rate, dimensionless numbers and velocity distribution on the outlet section are different before and after cavitation. Compared with diesel fuel, the microemulsificated bio-fuel needs higher injection pressure to start cavitatation and come up to supercavitaion. The existence of round inlet weakens cavitation and is unfavorable to the fuel spray. Besides, the predicted result by the model agrees well with Nurick’s equation.

Key words: Cavitation flow, Injector nozzle, Microemulsificated biomass fuel, Numeric simulation