Future Work

• By fitting Planck’s law to our spectra of boron-aluminum

flames, we can solve for temperature • Computer simulations of adiabatic flame temperature

show a decreasing temperature with increasing boron-aluminum ratios at higher dust concentrations

Method • Similar to how a flow of gas can be ignited to form a

Bunsen-type flame, a flow of powder can also be ignited to form a stabilized flame

• This hybrid flame laminar dust burner allows the study of aluminum-boron powders burning with or without methane

Introduction

• An investigation into the combustion properties of boron-aluminum mixtures burning in methane flames

• Boron has the highest volumetric energy density of any element, making it attractive for use as a potential fuel

• However, pure boron has poor combustion characteristics and a high ignition temperature

• Most current metallized propellants incorporate aluminum, which is easier to ignite than boron

• By doping aluminum with varying concentrations of boron we can hope to increase the amount of energy that can be harnessed from these fuels

Results cont.

• Preliminary results show that the flame speeds of boron-aluminum-methane mixtures are slightly lower than that of only aluminum-methane

0

50

100

150

Gasoline Aluminum Boron

[kJ/

cm^3

]

Volumetric Energy Density Results

• The spectra of aluminum-boron flames show peaks depicting overlapping BO2 and AlO bands, indicating the oxidation of boron and aluminum particles

400 450 500 550 600 650 700 750 800

400 500 600 700 800

Inte

nsity

(arb

. Uni

ts)

wavelength (nm)

Spectroscopy

Planck's law

Alex Wright - Mechanical Engineering - Alternative Fuels Laboratory Boron-Aluminum Hybrid Flames

Acknowledgments Thanks for the support and assistance from supervisors Prof.

Jeffery Bergthorson, Prof. David Frost and Dr. Samuel Goroshin, graduate students Michael Soo and Philippe Julien,

and fellow summer students Jean-Frédéric Ruel, Sam Whiteley and Jan Palecka

Aluminum-Boron-

Methane Flame

Methane Flame

Aluminum Flame

Aluminum-Boron Flame

Aluminum-Methane

Flame

Low Concentration

Medium Concentration

High Concentration

Aluminum-Boron-Methane Flames at Varying Concentrations

• Flame Speed is the rate at which a flame front propagates through a fuel-air mixture

• It depends on flame geometry, flow rates, and type of fuel

Theoretical results