Ignition and Combustion Characteristic of Aluminum and Magnalium Particles in AP/AN Composite Propellant

Abstract

Combustion efficiency of characteristic velocity is important factor that shows reaction situation in combustion chamber. And if a propellant burned completely in combustion chamber, C* combustion efficiency is 100%. However, metal particles are mixed in the propellant and metal particles are hard to completely burn. Therefore, there is a possibility that C* combustion efficiency decreases. It is necessary to evaluate the ignition and combustion characteristic of the metal particle. There is temperature distribution in the reaction zone of propellant. It is difficult to evaluate the ignition characteristic of the metal particle in reaction zone. We measured temperature gradient in the reaction zone by thermo couple of Pt-Pt10%Rh (the diameter is 12.5μm ). In the result, temperature fluctuations appeared by ignition of the metal. We obtained the ignition characteristic of the aluminum(AL) particle and magnalium(Mg-AL) particle from the fluctuations. And we obtained combustion time of aluminum particle in air. We calculated C* combustion efficiency when characteristic length (L*) is changed. Metal particles ignite on the burning surface. And it is considered that metals ignite in diffusion flame of AP particles on the burning surface. And combustion efficiency of characteristic velocity, η, of AL7μm completely burned when L* is 5m. And η of AL20μm completely burned when L* is 30m. Therefore, the smaller diameter of aluminum particle is, the shorter time for complete burning becomes. Nomenclature C* E L* M P Q R T c d m n q r x γ ρ Graduate Student Assistant Professor Professor (+ 81) 47-469-5431 (+ 81) 47-467-9569 triosu@kvf.biglobe.ne.jp 1 2 3 Phone: FAX: E-mail: = characteristic velocity = melting heat of aluminum = characteristic length = molar weight = pressure = amount of heat = universal gas constant = temperature = constant pressure specific heat = average diameter of aluminum particle = mass = number = combustion heat of per unit mass = burning rate = distance = specific heat ratio = density 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit 2 5 August 2009, Denver, Colorado AIAA 2009-4894 Copyright © 2009 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. American Institute of Aeronautics and Astronautics 2 η τ