Numerical investigation on the spray characteristics of biodiesel with gas-assisted atomization injection

Atomization is crucial for the application of biodiesel in APEs. GAAI is effective in solving the fuel atomization difficulty. The GAAI spray characteristics of biodiesel by numerical simulation are investigated. The influences of ambient pressure, fuel injection duration, and ambient temperature on spray characteristics are emphasized. The results show that a relatively large ambient pressure leads to a relatively small spray penetration depth and SMD. Smaller droplets are more susceptible to gas flow than larger droplets, and larger fuel droplets tend to move independently. A relatively long injection duration suggests that the fuel stays in the gas-assisted injector for too much time, resulting in excessive accumulation of droplets at the outlet of the nozzle. The larger the droplet size is, the less affected it is by ambient temperature. When the ambient temperature increases, the density of the ambient gas decreases, reducing momentum exchange between the gas and droplets. The temperature of large fuel droplets remains approximately the same as the initial fuel temperature.