Analysis of deflagration to detonation transition in high-energy solid propellants

The term "detonability" with respect to fuel-air mixtures (FAMs) implies the ability of a reactive mixture of a given composition to support the propagation of a stationary detonation wave in various thermodynamic and gasdynamic conditions. The detonability of FAMs, on the one hand, determines their explosion hazards during storage, transportation, and use in various sectors of the economy and, on the other hand, the possibility of their practical application in advanced energy-converting devices operating on detonative pressure gain combustion.

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EFFECT OF BORON ON THE COMBUSTION CHARACTERISTICS OF METALLIZED HIGH-ENERGY MATERIALS

NONEQUILIBRIUM PROCESSES: RECENT ACCOMPLISHMENTS ◽

10.30826/nepcap9a-31 ◽

2020 ◽

Author(s):

A. Korotkikh ◽

◽

I. Sorokin ◽

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Keyword(s):

Specific Impulse ◽

Equilibrium Composition ◽

Combustion Products ◽

High Energy ◽

Combustion Characteristics ◽

Solid Propellants ◽

Energy Materials ◽

High Energy Materials ◽

Condensed Combustion Products ◽

Active Fuel Binder

The paper presents the results of thermodynamic calculations of the effect of pure boron additives on combustion characteristics of high-energy materials (HEM) based on ammonium perchlorate, ammonium nitrate, active fuel-binder, and powders of aluminum Al, titanium Ti, magnesium Mg, and boron B. The combustion parameters and the equilibrium composition of condensed combustion products (CCPs) of HEM model compositions were obtained with thermodynamic calculation program “Terra.” The compositions of solid propellants with different ratios of metals (Al/B, Ti/B, Mg/B, and Al/Mg/B) were considered. The combustion temperature Tad in a combustion chamber, the vacuum specific impulse J at the nozzle exit, and the mass fraction ma of the CCPs for HEMs were determined.

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DEFLAGRATION-TO-DETONATION TRANSITION IN A STRATIFIED SYSTEM “GASEOUS OXYGEN-LIQUID FILM OF N-DECANE”

NONEQUILIBRIUM PROCESSES. Vol. 2. Fundamentals of combustion ◽

10.30826/nepcap2018-2-30 ◽

2020 ◽

Author(s):

S. M. FROLOV ◽

◽

V. S. AKSENOV ◽

I. O. SHAMSHIN ◽

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...

Keyword(s):

Liquid Film ◽

Ignition Source ◽

Gaseous Oxygen ◽

Deflagration To Detonation Transition ◽

Operation Process ◽

Continuous Detonation ◽

Smooth Channel ◽

Detonation Transition ◽

Run Up ◽

X 24

Deflagration-to-detonation transition (DDT) in the system “gaseous oxygen- liquid film of n-decane” ' with a weak ignition source was obtained experimentally. In a series of experiments with ignition by an exploding wire that generates a weak primary shock wave (SW) with a Mach number ranging from 1.03 to 1.4, the DDT with the detonation run-up distances 1 to 4 m from the ignition source and run-up time 3 ms to 1.7 s after ignition was observed in a straight smooth channel of rectangular 54 x 24-millimeter cross section, 3 and 6 m in length with one open end. The DDT is obtained for relatively thick films with a thickness of 0. 3-0.5 mm, which corresponds to very high values of the overall fuel-to-oxygen equivalence ratios of 20-40. The registered velocity of the detonation wave (DW) was 1400-1700 m/s. In a number of experiments, a high-velocity quasi-stationary detonation-like combustion front was recorded running at an average velocity of 700-1100 m/s. Its structure includes the leading SW followed by the reaction zone with a time delay of 90 to 190 s. The obtained results are important for the organization of the operation process in advanced continuous-detonation and pulsed-detonation combustors of rocket and air-breathing engines with the supply of liquid fuel in the form of a wall film.

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Flame Speed and Deflagration-Detonation Analysis in Flare Stack and Header

Volume 2: Development and Applications in Computational Fluid Dynamics; Industrial and Environmental Applications of Fluid Mechanics; Fluid Measurement and Instrumentation; Cavitation and Phase Change ◽

10.1115/fedsm2018-83445 ◽

2018 ◽

Author(s):

Philip Diwakar ◽

Jaleel Valappil

Keyword(s):

Ambient Air ◽

Flame Speed ◽

Safety Concerns ◽

Deflagration To Detonation Transition ◽

Detonation Transition

This paper examines safety concerns related to flame speeds when warm relief gas snuffs out the pilot at the flare stack and pulls in ambient air and a spark ignites the vapor in the header. The flame speed essentially determines if the propagating flame speed is a deflagration or a detonation based on whether its subsonic or supersonic. While pipes are sized for deflagrations, they need to be analyzed and tested for detonation pressures and temperatures. Transient CFD calculations help determine the flame speeds, deflagration to detonation transition, pressures and temperatures are compared to pipe specifications and help determine if a detonation leads to a Loss of Containment and suggests mitigations.

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