Analysis of equilibrium flows in detonation waves in gases

Initiation of bubble detonation in the system "inert liquid-explosive gas bubbles" by a detonation wave in a gas was studied experimentally. Compression-wave pressure profiles were determined as functions of the length of the initiation section and the initial pressure of the explosive gas mixture in it. It was shown that because of the effect of the explosive-gas volume between the diaphragm and the upper boundary of the bubble medium, the pressure in front of the initiating wave increased much more slowly than the initial pressure. The optimal length of the initiation section was found, and the critical (minimum) initiation pressure in it and at the shock-wave front were determined. It was found that for a fixed gas volume concentration in the bubble medium, the pressure in the initiation section increased insignificantly as the length of the section decreased.

mentioning

confidence: 82%

mentioning

confidence: 94%

Bubble detonation conditions

Kochetkov

Pinaev

2007

“…For this purpose, the temperature and the mole fraction of OH radicals obtained in exact thermodynamic calculations [3,4] were substituted into the above-given formulas, and the equilibrium composition of the mixture was calculated.…”

Section: And Verification Of the Methodsmentioning

confidence: 99%

“…Following [3,4], we introduce n = 2 b 0 i , which is the total number of all atoms involved into the reaction (n remains unchanged in the course of the reaction) and the "mole fraction" of all atoms:…”

Section: System Of Reactionsmentioning

confidence: 99%

Method of reconstruction of the chemical composition and combustion efficiency of hydrogen-air mixtures from incomplete experimental data

Topchiyan

2008

Self Cite

A principal possibility of approximate reconstruction of the chemical composition in combustion of a hydrogen-air mixture at the end of the scramjet duct from incomplete experimental data (measured concentration of OH radicals and temperature) under the assumption of detailed chemical equilibrium of exchange reactions is analyzed. A closed algebraic system of equations including the concentration of OH radicals and the temperature as parameters is derived in this approximation. A code for solving this system numerically is developed for approximate determination of reaction completeness from the measured temperature and concentration of OH radicals. The model was tested by results of exact thermodynamic calculations of the Jouguet state and overdriven waves in a stoichiometric hydrogen-air mixture and various hydrogen-oxygen mixtures. In the range of pressures of 0.2 to 500 atm and temperatures of 2500 to 3500 K, this method allows the molecular weight and heat release to be reconstructed with accuracy sufficient for gas-dynamic calculations.

“…It is difficult to explain such a behavior of transverse waves from the viewpoint of the classical detonation theory [12], where the detonation velocity is fairly definite and depends far from the detonation limits only on the physical and chemical parameters of the mixture; the detonation velocity in the gas mixture depends only weakly on the initial temperature, pressure, and density [13,14]. Hence, the process of TDW propagation in a moving and gradually mixing flow of the components is more complicated, because it involves additional physical factors in the form of nonuniform distributions of parameters of the mixture ahead of the TDW front over its height (φ, P , ρ, T , velocity v z , cross-sectional area of the mixture S c1 , etc.…”

Section: Detonation With Exhaustion Of the Products Into An Evacuatedmentioning

confidence: 99%

Continuous spin detonation of hydrogen-oxygen mixtures. 2. Combustor with an expanding annular channel

Быковский

Ждан

Ведерников

2008

A comprehensive numerical and experimental study of continuous spin detonation of a hydrogen-oxygen mixture in an annular combustor with the components supplied through injectors is performed. The hydrogen-oxygen mixture is burned in the regime of continuous spin detonation in an annular combustor 4 cm in diameter with subsequent channel expansion. The flow structure is considered for varied flow rates of the components of the mixture and the counterpressure of the ambient medium. The dynamics of the transverse detonation wave is numerically studied in a two-dimensional unsteady gas-dynamic statement of the problem with the geometric parameters of the combustor consistent with experimental ones. Reasonable agreement with experiments is reached in terms of the shape of detonation fronts, detonation velocity, and height of the wave front. The optimal point of channel expansion beginning is chosen, which ensures the maximum specific impulse in the spin detonation regime.