Ammonium perchlorate

About: Ammonium perchlorate is a research topic. Over the lifetime, 2359 publications have been published within this topic receiving 33412 citations. The topic is also known as: AP.

Burning of Aluminized Solid Rocket Propellants: from Micrometric to Nanometric Fuel Size

Abstract: A survey is offered of the present status of microaluminized propellants industrially used worldwide in most space applications, and also new directions are pointed out making profitable use of the nanoaluminized propellants meanwhile tested in advanced international laboratories. The survey is limited to formulations with inert binders. Different industrialand research-type of solid rocket propellants, mainly but not only, of the family AP/Al/HTPB were experimentally analyzed at the Space Propulsion Laboratory of Politecnico di Milano. In general, they feature the same nominal composition but implement different grain size distributions of the oxidizer or metal fuel. The basic properties of all formulations were compared to that of a standard 68/18/14 propellant already certified for flight. In order to test their possible eligibility in terms of performance for future launchers, steady ballistic properties in terms of burning rate and flame structure were studied by a variety of experimental techniques ranging from high-speed and high resolution digital video recording to chemo-physical analyses of the solid combustion residues. Surprising differences were revealed in the flame structure of apparently similar formulations. In turn, this allowed shedding new light on the complex phenomena governing metallized solid rocket propellant burning and thus acquiring improved prediction capabilities of motor performance. Nomenclature Roman symbols Al = metallic aluminum Al2p = aluminum oxide content in XPS analysis Al2O3/Al = aluminum oxidation efficiency Alox = aluminum oxide at.% = atomic concentration C1s = carbon content in XPS analysis C2Cl4 = inert liquid Cl2p = chlorine content in XPS analysis Dp = particle diameter, μm D43 = mass mean diameter, μm DAP = mean ammonium perchlorate grain size, μm Is = specific impulse, s Is,ideal = ideal (adiabatic thermochemical equilibrium) specific impulse, s n = steady burning rate pressure sensitivity O1s = oxide content in XPS analysis p = pressure, bar qr = radiant flux, W/cm rb = steady burning rate, mm/s tign = ignition time, ms (t*)cc = average residence time in combustion chamber, ms (Vcc/Ab)1/2 = combustion chamber free volume / burning area ratio at half burning time, m Greek symbols ΔIs = specific impulse loss, s ηc* = efficiency of characteristic velocity, % ηcs = efficiency of thrust coefficient, % ηIs = efficiency of specific impulse, % ρcc = combustion chamber gas mixture density, g cm ρp = propellant density, g cm α-Al2O3 = stable phase alumina or Corundum Abbreviations AP = Ammonium Perchlorate CCPs = Condensed Combustion Products HTPB = Hydroxyl-Terminated Polybutadiene MOPs = Micrometric Oxide Particles SEM = Scanning Electron Microscopy SOPs = Smoke Oxide Particles TMD = Theoretical Maximum Density XPS = X-Ray Photoelectron Microscopy XRD = X-Ray Diffraction 1

A numerical study of periodic sandwich propellants with oxygenated binders

Abstract: We examine sandwich propellants constructed from sheets of pure ammonium perchlorate (AP) interleaved with an AP/binder blend, and construct solutions numerically using a code that fully couples gas-phase and solid-phase processes via an unsteady moving interface. This code has been used elsewhere to simulate the burning of random packs of spherical AP particles embedded in binder. We show that for a stoichiometric configuration, variations of the burning rate with α (a measure of the oxygenation of the AP/binder blend) are not monotonic, but display a weak maximum; and variations of the burning rate with sandwich thickness are monotonic for small α, but display a minimum for large α (e.g. α = 0.5). When the equivalence ratio is varied, the burning rate displays a maximum on the fuel-lean side when α is small, on the fuel-rich side when α is large. These results, and the manner in which the sandwich topography varies with the different parameters, suggest that the configuration could be invaluable for val...

Gas generating compositions containing ammonium sulfate acceleration force desensitizer

Abstract: A gas generating composition having decreased sensitivity to compressive acceleration forces The composition comprises an intimate mixture of ammonium perchlorate oxidizer and elastomeric fuel binder in such proportions as to provide a burning rate of 005 to 03 inches per second at a pressure of 1000 psia and has incorporated therein 5 to 35% of ammonium sulfate as an acceleration force desensitizing agent