Vaporization and Combustion of a Soybean Biodiesel Droplet in Turbulent Environment at Elevated Ambient Pressure

Abstract

This article reports experimental data on the vaporization and combustion of soybean (derived) biodiesel droplet in turbulent environment at elevated ambient pressure and temperature conditions. Test conditions consisted of varying turbulence intensity and ambient pressure while keeping ambient temperature constant at 473 K. Soybean biodiesel droplet was formed using an in-house developed injector, and suspended onto the tip of a quartz fiber in the center point of a spherical vessel. The initial diameter of the formed droplet ranged between 1.00 mm and 1.50 mm. The characterization of the turbulent field, generated by four pairs of axial fans, revealed that turbulence is essentially isotropic and homogeneous with nearly zero-mean flow within the 40-mm-diameter volume in the center of the vessel. The experimental results showed that the biodiesel droplet vaporization and burning followed the d2-law. More importantly, the biodiesel droplet vaporization rate was shown to depend on both turbulence and ambient pressure. The droplet vaporization results showed that the effect of turbulence becomes more effective with increasing ambient pressure. In addition, turbulence was found to enhance the biodiesel droplet burning rate only at elevated ambient pressure. Heat loss from the flame predominates at high levels of turbulence, which consequently causes droplet flame extinction.