Performances analysis of novel heated tip injector with multi-physical fields coupling simulation

A novel heated tip multi-hole spark ignition direct injection (SIDI) injector is designed and manufactured. Compared with the conventional SIDI injector, the novel heated tip SIDI injector can heat the fuel and increase the fuel temperature in a short time. The relationship and formation among the electromagnetic, thermal, fluid flow and spray fields are analyzed based on coupling theories. The data information interface platform based on the commercial software is used to calculate the key parameters of the novel SIDI injector. The coupling models based on FEM (Finite element method) are established to analyze the comprehensive performances systematically. The systematic experiments are utilized to validate and verify the coupling mechanism and the accuracy of the simulation model. In order to investigate the relationship between the temperature and performances of the injector, the multi-physical fields coupling analysis of the novel heated tip SIDI injector are carried out by simulation and experiments. According to the systematical analysis, it is found that the heat generate from the heater and magnetic circuit is the most significant factor that influence on the electromagnetic field, fluid flow and spray. The experiment and simulation result shows that the maximum temperature on the heater of the SIDI injector is about 160 °C, which is sufficient to heat the fuel in the injector chamber to boiling, and the flow pattern moved to a developed cavitation at a higher temperature. The main spray plumes completely disappear as the temperature achieves 120 °C, which indicates that the spray has totally collapsed, and the spray particle size can be significantly reduced by increasing the fuel temperature.