Expériences sur la propagation des détonations dans un milieu biphasique

Saint-Cloud, J. P.; Guerraud, C.; Moreau, Marie-France; Manson, N.

doi:10.1016/0094-5765(76)90111-9

Cited by 13 publications

(10 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This reinforces the findings of Saint-Cloud et al (1976) who showed that the detonation velocity and pressure did not depend on foam density. on the heat of reaction of the gaseous mixture.…”

Section: Discussionsupporting

confidence: 91%

“…The foams were produced from a solution of 5% in volume of commercial detergent in water with the generator described in detail by Saint-Cloud et al (1976). The Sauter diameter d~~ was determined with the help of macrophotographs or a foam sample (Saint-Cloud et al 1976).…”

Section: Foamsmentioning

confidence: 99%

“…In a previous study on the propagation of detonations in aqueous foams filled with a stoichiometric propane-oxygen mixture (at ordinary pressure and temperature), Saint-Cloud et al (1976) observed that for a foam density p (5 < p < 25 kg/m 3 ), two regimes of propagation coulcP be observed, according to the foam structure. The foam is characterized by the Sauter diameter d^ (cU 2 = ^ n -d?/I n.…”

Section: Introductionmentioning

confidence: 98%

See 2 more Smart Citations

Detonations in Explosive Foams

Saint-Cloud¹

1985

Dynamics of Shock Waves, Explosions, and Detonations

View full text Add to dashboard Cite

Previous work has shown that two different regimes of detonation may appear for a foam density range of 5 to 25 kg/m 3 in an aqueous foam filled with a stoichiometric propane-oxygen mixture. When the majority of the bubbles have a diameter greater than 2-3 mm, the phenomenon observed is very similar to that of a premixed gaseous detonation ; this regime is called the Normal Regime of Detonation (NRD). When the predominant diameter is less than 2 mm, the shock and the combustion fronts are clearly separated and their velocities are markedly lower than that of the detonation in the gaseous mixture alone. This regime is called the Double Front Regime (DFR). In the present work, under the same experimental conditions, the influence of the gaseous mixture composition is established.Experiments were performed with stoichiometric mixtures (2H 2 + 0 + ZN 2 , CH, +20+ ZN 2 , C 2 H, + 3 0 2 + ZN 2 and C 3 H g + 5 6 2 + ZN 2 ). At a given mean bubble diameter and foam density, a maximum dilution limit -Z.. . -is observed beyond which the NRD is not observed. The dependence of the critical predominant bubble diameter on the dilution of nitrogen (Z) at the transition from NRD to DFR was determined.

show abstract

Section: Discussionsupporting

confidence: 91%

Section: Foamsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

Detonations in Explosive Foams

Saint-Cloud¹

1985

Dynamics of Shock Waves, Explosions, and Detonations

View full text Add to dashboard Cite

show abstract

“…Manson et al [8] made a detailed investigation of galloping detonation for propane-oxygen-nitrogen mixtures in tubes of different length l and diameter D. From streak Schlieren photographs, they found that the detonation wave decays to a shock wave with a trailing reaction zone, and re-couples again during reacceleration to the overdriven state. Saint-Cloud et al [9] investigated in more detail the structure of galloping detonations in propane-oxygennitrogen mixtures in a 10 Â 20 mm tube and found that the reaction zone completely separated from the leading shock during the low velocity phase of the galloping cycle. Subsequently the shock and reaction front re-coupled again in the acceleration to overdriven phase of the galloping cycle.…”

Section: Introductionmentioning

confidence: 98%

Experimental characterization of galloping detonations in unstable mixtures

Gao

Lee

2015

Combustion and Flame

View full text Add to dashboard Cite

a b s t r a c tSome features of galloping detonations near the detonation limits are discussed in this paper. The experimental results previously reported in , together with additional data obtained in this study for six explosive mixtures with different reaction sensitivities, each in five different diameter tubes, are analyzed in detail. It is established that galloping detonations do not occur in highly argondiluted, stable mixtures. Only in unstable mixtures, susceptible to flow fluctuations by thermo-chemical instability, when using in small tube diameters (i.e., D 6 12.7 mm), could galloping detonations be observed. For the largest tube diameter D = 50.8 mm, the detonation wave fails completely when the initial pressure approaches the detonation limit even for all unstable mixtures. In addition, the present study shows that the initial pressure range for the occurrence of galloping detonations decreases rapidly with increasing tube diameter. A collection of existing data on galloping detonations indicates that the wavelength L of one galloping cycle is on average about 350D within experimental variations.Nonetheless, there appears to be some minor decreasing trend with increasing tube diameter (i.e., D P 12.7 mm), or with increasing detonation instability of the explosive mixture. The amplitude of the galloping cycle is also investigated and the upper velocity values show more fluctuations than the lower ones. The upper and lower values of the velocity in the galloping cycle at different conditions vary from V CJ to 1.5V CJ and 0.3V CJ to 0.65V CJ , respectively. To illustrate the role of flow instability on galloping detonations, experiments are performed with a spiral inserted into the 12.7-mm diameter tube to generate perturbations artificially. Detonation waves are observed to re-initiate quickly after passing the spiral and another cycle of galloping detonation was formed in the remaining part of the tube.

show abstract

“…Nonetheless, several experimental studies with inert particles can be found in the literature. Examples include the investigations conducted by Laffite and Bouche [1], Saint-Cloud et al [2], Mamontov et al [3], Kaufmann et al [4], Sedov et al [5], Klemens et al [6], Grigorev [7], Kozhevnikov [8], Zhang et al [9], Carver et al [10], and others. These studies suggested that very small particle diameters or sufficiently high particle concentrations can result in detonation failure (quenching) due to increased energy and momentum transfer from the gas to the particles.…”

Section: Introductionmentioning

confidence: 97%

Influence of inert particles on the propagation of multidimensional detonation waves

Papalexandris

2005

Combustion and Flame

View full text Add to dashboard Cite

Expériences sur la propagation des détonations dans un milieu biphasique

Cited by 13 publications

References 2 publications

Detonations in Explosive Foams

Detonations in Explosive Foams

Experimental characterization of galloping detonations in unstable mixtures

Influence of inert particles on the propagation of multidimensional detonation waves

Contact Info

Product

Resources

About