It is well known that reduction of Ammonium Perchlorate (AP) content in composite propellant reduces the burn rate of solid composite propellants. Below a certain level of AP content the propellant does not burn. This paper explores ways to enhance the burn rate of fuel-rich composite solid propellant. The methods employed to enhance the burn rate of the propellant in the study are 1) Use of pyral 2) Recrystallization of AP, 3) Method to add catalyst into the propellant and 4) Addition of AC with moisture. Pyral was added as a metal fuel which resulted in propellants having higher burn rates and their density variations along the length were absent contrary to those without pyral. Addition of AC with moisture in these propellants increases the burn rate pressure index. The highest burn rate achieved is 3.8 mm/s at 70 bar with the propellant comprised of AP (particle size < 15 µm) and nano-sized catalyst. © 2013, American Institute of Aeronautics and Astronautics Inc. All rights reserved.

Periyapatna A. Ramakrishna

Department of Aerospace Engineering

Fuels

Moisture

Nanocatalysts

particle size

Propulsion

Solid propellants

AMMONIUM PERCHLORATES

Burn rates

Composite solid propellant

Density variations

FUEL-RICH PROPELLANT

NANOSIZED CATALYSTS

Composite propellants

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Development of AP/HTPB based Fuel-rich Propellant for Solid Propellant Ramjet

49th AIAA/ASME/SAE/ASEE Joint Propulsion Conference

In this paper, experimental results of an aluminized fuel-rich propellant having energetics similar to boron-based fuel-rich propellant and having no residue after combustion are discussed. Using this aluminum-based fuel-rich propellant, which has higher density than the current fuels used for hypersonic flight, this paper looks at enhancing the Mach number envelope of a ramjet. Nondimensional thrust and drag calculations were carried out to identify the air-fuel ratio required for a Mach 6 flight, with different intakes accounting for different pressure recovery. Calculations were carried out with three different intakes, and it was observed that, even with the lowest pressure recovery of 9% at Mach 6, a hypersonic mission was possible. Values for various efficiencies were chosen with great care, and a perturbation analysis was carried out to make the calculations more robust. The specific impulse obtained with the aluminum-based fuel-rich propellant in ramjet mode was 515 s at a 25 km altitude. Comparison of an aluminum-based fuel-rich propellant in ramjet mode was made with a kerosene and hydrogen fueled scramjet from the specific impulse data available in the literature. The specific impulse of the aluminum-based fuel-rich propellant was nearly an order of magnitude higher as compared to a hydrogen fueled scramjet when adjusted to the density of hydrogen. Upon considering a system size, it was also shown that the aluminum-based fuel-rich propellant could meet the burn rate requirement for a Mach 6 flight. © 2017 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

Journal of Propulsion and Power

Attaining hypersonic flight with aluminum-based fuel-rich propellant

Development of ap/htpb based fuel-rich propellant for solid propellant ramjet

Nano-aluminium particles of ∼50 nm size, produced at this laboratory, are added to composite solid propellants based on ammonium perchlorate and hydroxyl-terminated poly-butadiene binder that exhibit plateau burning rate trends and those including burning rate catalysts. The nano-aluminized propellant burning rates are compared with corresponding micro-aluminized and non-aluminized ones in the 1-12 MPa pressure range. The mid-pressure extinction of the matrixes containing the fine-sized ammonium perchlorate particles in the propellant along with the binder is investigated in all the cases to understand the mechanism of plateau-burning. Further, the variations in aluminium content, the aluminium size (within nano- and micro-ranges), bimodal combination of nano- and micro-aluminium are considered. Ferric oxide and titanium dioxide are the burning rate catalysts considered. Large scale accumulation of aluminium is observed not only in micro-aluminized matrixes, but also in nano-aluminized ones as clusters of 1-5 μm size. Since aluminium is added at the expense of the coarse ammonium perchlorate particles to preserve the total-solids loading in the present formulations, addition of micro-aluminium decreases the burning rate; whereas, nano-aluminized propellants exhibit ∼80-100% increase in the burning rate under most conditions. The near-complete combustion of nano-aluminium close to the burning surface of the propellant provides heat feedback that controls the burning rate. Mid-pressure extinctions of matrixes and plateau burning rates of propellants are washed out when nano-aluminium is progressively added beyond 50% in bimodal aluminium blends, but low pressure-exponents are observed in the nano-aluminized propellant burning rates at elevated pressures. Adjusting the plasticizer content in the binder alters the pressure range of plateau burning rates in non-aluminized propellants. Catalysts increase the burning rate by ∼50-100% in non-aluminized and micro-aluminized propellants, but in nano-aluminized propellants, the μm-sized catalyst does not affect the burning rate significantly; whereas, the nanometre size catalysts increases the burning rate merely by ∼5-15%. © 2009 The Combustion Institute.

Combustion and Flame

Effect of nano-aluminium in plateau-burning and catalyzed composite solid propellant combustion

Propellants, Explosives, Pyrotechnics

Burning Characteristics and Thermochemical Behavior of AP/HTPB Composite Propellant Using Coarse and Fine AP Particles

Proceedings of the Combustion Institute

The effects of bimodal aluminum with ultrafine aluminum on the burning rates of solid propellants

Journal	Data powered by Typeset49th AIAA/ASME/SAE/ASEE Joint Propulsion Conference
Publisher	Data powered by TypesetAmerican Institute of Aeronautics and Astronautics Inc.
ISSN	0001-1452
Impact Factor	1.868
Open Access	No
Citation Style	unsrt
Sherpa RoMEO Archiving Policy	Green