Showing papers on "Burn rate (chemistry) published in 1970"

Effect of radiant energy on the burning rate of a composite solid propellant

Abstract: This paper describes the measured effect of radiant energy flux on the atmospheric pressure burning rate of a solid propellant. It was concluded that the effect is negligible except when the propellant burning rate is very low as, for example, during the quench of a controllable motor. Also, from the experimental data, it was calculated that the PBAN-AP propellant had an apparent surface temperature of 560 °C and an apparent exothermic solid decomposition that liberated 130 cal/g.

Solid propellant motor

Abstract: A case bonded end burning solid propellant rocket motor utilizing a propellant having sufficiently low modulus to avoid chamber buckling on cooling from cure and sufficiently high elongation to sustain the stresses induced without cracking, the propellant being zone cured within the motor case at high pressures equal to or approaching the pressure at which the motor will operate during combustion. A solid propellant motor having a burning time long enough that its spacecraft would be limited to a maximum acceleration of less than 1 g is provided by one version of the case bonded end burning solid propellant motor of the invention.

The Morphological Continuum in Solid Propellant Grain Design

Abstract: Grain configurations for solid propellant rockets are classified by relative web thickness and mean vector direction of burning surface into a topological continuum. This ranges from the thin web dendrite (web equal to 1/6 of charge radius and entirely in the cross-section plane) thru the wagon-wheel- and star-perforated grains (1/4 to 1/2 web range and partial use of end effects in burning surface area control) to the slotted, conocyl, and finocyl grains (web 0.6–0.8 of radius and burning front partially in the axial direction). These geometrical principles relate to the mission by the ratio of thrust-to-duration squared (F/t 2) which requires a dendrite grain for F/t 2≈ 3000 1bf/sec2 and a slot or finocyl for F/t 2≈ 30 1bf/sec2. This effect is counterbalanced by the range of burning rates available. Burning rate, relative web thickness, chamber pressure, length-to-diameter ratio, and volumetric loading affect F/t 2 attainable in a descending significance. The prevailing style of grain design in any era, although optimized mathematically within itself, depends more on technological breakthroughs in materials and propellant properties, than on factors of ballistic performance. Grain design is primarily a graphic subject. There are two aspects: performance attributes and description of the grain configuration.

A Feasibility Study of Command Control of Solid Propellant Burning Rate

Abstract: : Analytical studies of twenty methods of command control of burning rate were performed to help establish which methods are most likely to be effective. Any method which offers a plus or minus 5% or greater throttle ability is of interest. Since the study was not directed at a particular application, problems of implementation were not considered in detail. The approaches which received the greatest attention include: thermal radiation by injected particles and inserted intensifiers, acoustic energy, penetration of thermal wave by back flow of combustion gased into either perforated propellants or embedded porous elements, injection of burning rate catalysts, rammed propellant surfaces, and resistive heating. Other methods which were surveyed include: partial quenching, heating through vibration, induced unstable burning, dielectric heating, resistive wire networks, electrical and electromagnetic effects on flames and ingredient decomposition, acceleration forces, and utilization of photochemical processes.