Chapter 7 - Impulse production by injecting fuel-rich combustion products in air

• Published in: Combustion Processes in Propulsion pp. 329 - 340
• Main Author: Borisov, A.A.
• Format: Book Chapter
• Language: English
• Published: Elsevier Inc 2005
• ISBN: 9780123693945; 0123693942
• DOI: 10.1016/B978-012369394-5/50035-4

This chapter demonstrates the possibility of generating a strong reactive shock wave by injecting partially burnt monopropellant in air. Nitromethane and isopropyl nitrate are fuel-rich energetic materials that are used as model monopropellants. These are injected into the combustion chamber and they react with air, supporting reactive shock waves that spread at a velocity of up to 1400 m/s. The introduction of obstacles in the combustion chamber provides much better mixing than in an unobstructed chamber. Unsteady reactive shock waves are more efficient impulse generators than the detonation of a homogeneous monopropellant mixture with air. The injection of a preconditioned fuel in the main chamber filled with air helps to overcome the problems associated with Chapman–Jouguet (CJ) detonation used in pulsed detonation engines (PDEs). This injection process combines mixing and reactive-shock generation in a single process. The injection of the decomposition products of a small amount of monopropellant together with a conventional hydrocarbon fuel can generate high-pressure jets.