Experiment and Simulation Analysis of Ethanol-Biodiesel Spray Characteristics

The spray of ethanol-biodiesel at ultra-high injection pressure, different ambient pressures and temperatures under transient flow in the coupled nozzle was characterized, and sensitivity of the maximum particle concentration under different conditions was analyzed. A three-dimensional calculation grid of the nozzle and spray domain was established on Ansys, and reliability of the spray model was verified by constant volume combustion bomb spray experiment. The injection pressure greatly influences SMD and droplet velocity. Within 1 ms, the SMD of E20B80 is reduced by 18.9%, the droplet velocity and STP increase by 16% and 8.7% respectively, and the average sensitivity of the maximum particle concentration is 0.35. The ambient pressure compared with the injection pressure significantly inhibits the STP and SMD of the fuel droplets. When the ambient pressure rises from 0.1 to 1 MPa, the STP and SMD of the fuel droplets decrease by 123% and 71.8%, respectively. The maximum speed is enhanced by 51.9%, but the average sensitivity of ambient pressure to the maximum particle concentration is maximized to 0.36. Unlike the ambient pressure, the ambient temperature significantly promotes the STP and SMD. When the ambient temperature rises from 300 to 600 k, the STP and SMD of the fuel droplets increase by 13.4% and 27%, respectively. The maximum velocity of droplet particles is raised by 2.7%, and the average sensitivity of ambient temperature to the maximum particle concentration is only 0.027