Injection spray macroscopic visualization and structure of Jojoba biodiesel-water emulsion into an atmospheric chamber

An experimental investigation has been carried out to visualize the spray characteristics of Jojoba biodiesel - water emulsion fuel injected into an atmospheric chamber. An injection pump for a real diesel engine has been used to inject pure Jojoba biodiesel, its emulsions with water at 5, 10 and 15 % water by volume in an atmospheric chamber. The injected spray data have been compared to the case of pure diesel fuel to present the differences in case of using Jojoba biofuel or its water emulsions. A visualization system comprises a high-speed video camera, LED lights, data acquisition system and a desktop PC that have been used to store the visualization data of the injection process at the rate of 40,000 frames per second. Forty frames from injection onset with a total duration of 1 millisecond have been stored in a computer for off-line analysis. The data presented included the time-history of spray tip penetration (total, in radial and in axial directions), spray cone angle, spray cone diameter, spray cone area / volume, spray injection rate, and spray tip velocities (total, radial and axial). The data also included timed frames of the injection spray cones from the onset of injection for a duration of one millisecond for the five fuels tested. The main differences for the injection spray characteristics of the jojoba biodiesel – water emulsions compared to the pure jojoba biodiesel and pure diesel fuels have been presented. The 15 % jojoba biodiesel – water emulsion exhibited the slowest spray with the least spray tip penetration, least spray cone area and volume, and least spray tip velocities compared to other emulsions, biodiesel or pure diesel.