Study on the Burning of a Fuel Drop in Heated and Pressurized Air Stream : 1st Report, Experiment

Abstract

As a clue to elucidating the combustion process in diesel engines, the burning characteristics of a fuel drop in heated and pressurized air stream was studied experimentally. Its pressure was varied from 0.4 to 16 ata, its temperature, from the room temperature to 600°C, and its velocity, up to the transition velocity where the flame shape changes from envelope type to wake type. The fuel drops were simulated by porous spheres transpired liquid fuel. As the fuel, methanol, n-butanol and kerosene were used. Under these conditions, the flame shape, the burning rate m, and the flame transition air velocity U_c were measured. Among the results of measurement, main ones concerning the influence of temperature and pressure are as follows. When the temperature is raised, U_c rapidly icnraeses, but m scarcely changes. When the pressure is raised with the velocity, m increases remarkably. And when the temperature and the pressure are raised, flame becomes long and the soot formation increases.