Velocities of Reacting Boron Particles within a Solid Fuel Ramjet Combustion Chamber

A 2D-laser doppler velocimeter was used to measure velocities of reacting boron (B) particles during the combustion of a metallised solid fuel slab inside a 20-combustion chamber. The solid fuel hydroxyl-terminated polybutadiene (HTPB) was enriched with B particles to increase its specific heat. To obtain information on the combustion process and on the movement of B particles, their velocities were measured. The experiments were performed at ambient pressure. The behaviour of the B particles concerning the exit velocities from the fuel slab has been discussed on the basis of the experimental results

Investigation of the Combustion Behaviour of Solid Fuel Slabs in a Planar Step Combustor with a Colour Schlieren Technique

The combustion behaviour of solid fuel slabs with and without boron particle addition has been investigated with a Colour Schlieren technique in a planar step combustor under ramjet relevant conditions concerning the air inlet temperature. Large scale vortical structures are conspicuous in the outer zone above the diffusion flame in the developing boundary layer behind the recirculation zone. On Colour Schlieren pictures with longer exposure times the superimposed thermal emission from the flame region gives additional information on the location of the flame front

Comparison of PIV and Colour-Schlieren Measurements of the Combustion Process of Boron Particle Containing Solid Fuel Slabs in a Rearward Facing Step Combustor

Particle Image Velocimetry (PIV) and Colour-Schlieren measurements have been used in order to investigate the combustion process of solid fuel slabs with boron particle addition in a step combustor under ramjet relevant conditions concerning the air inlet temperature. The high time resolution of both measurement techniques (-13 µs for Schlieren and 10 ns for PIV) show a quasi frozen state of the flow. With both techniques large scale vortical structures were observed in the outer zone above the diffusion flame in the developing boundary layer behind the recirculation zone

Overview of the German Gel Propulsion Technology Program

Gel propellants offer the possibility to build throttleable propulsion systems with easy handling and storage characteristics. This publication gives an overview of the conducted basic research activities and the technology development work within the German Gel Propulsion Technology Program, which was started in 2001. It covers various aspects of gel production, rheological properties, flow behavior, spray characteristics and combustion behavior, their application in rocket combustors and at least the successful free flights of two demonstrator missiles, each with a gel rocket engine on December 2nd, 2009. To sum up, one can say that up to now the understanding of basic processes as well as the knowledge about combustor and engine technology on gel propulsion could significantly be improved. The progress shows that the technology is ready for first applications, but nevertheless, there are still open gaps to close