Combustion and micro-explosion characteristics of biodiesel–ethanol–aluminum powder particles droplet under simulated air nitrogen–oxygen

Abstract

Compared with aviation fuel, biodiesel has a smaller energy density, so the flight range of aircraft using biodiesel as aviation fuel is relatively short. Adding aluminum powder particles can significantly improve the energy density of fuel and then improve the flight range of aircraft, but the combustion characteristics of fuel will change after adding aluminum powder particles to fuel. In this experiment, a tubular furnace was used to simulate the ratio of nitrogen to oxygen in air, and the micro-explosion and combustion characteristics of BD60E40 droplet and BD60E40 droplet 10%AP (8 μm) under 700 and 750 °C were compared and studied by using moving droplet tracking technology. It is found that the greater the steam pressure inside the droplet, the greater the intensity of micro-explosion, and the greater the initial velocity of the secondary droplet after micro-explosion. In addition, it is found that the proportion of aluminum powder in droplets increases gradually during the combustion cycle, and the frequency and intensity of micro-explosion of droplets increase gradually. The instantaneous combustion micro-explosion intensity model and the average combustion intensity model were established. It was found that the average combustion micro-explosion intensity of droplets increased gradually with the increase in temperature through calculation.