An Experimental Investigation of Rise Times of Very Weak Shock Waves.

Holst-Jensen, O.

doi:10.21236/ada108416

Cited by 4 publications

(2 citation statements)

References 2 publications

(2 reference statements)

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“…However, ignition in industrial applications and engines is commonly initiated by electrical spark igniters. Some experiments in academic configurations investigated blast waves from electrical spark discharges [25][26][27][28]. To the knowledge of the authors, no experimental study regarding blast waves in industrial applications or engines is available, but some papers assume their existence [29,30].…”

Section: Theoretical Considerationsmentioning

confidence: 99%

An Experimental Investigation of Kerosene Droplet Breakup by Laser-Induced Blast Waves

Gebel¹,

Mosbach²,

Meier³

et al. 2013

Journal of Engineering for Gas Turbines and Power

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The work presented in this paper intends to deepen our understanding of the mechanisms involved in the spark ignition of liquid fuel sprays. An experimental study is presented regarding the ignition of monodisperse droplet chains of Jet A-1 aviation kerosene in a generic model combustor under well-defined boundary conditions. Breakdowns created by focused laser radiation were used as ignition sparks. They featured rapid spatial expansion, resulting in the formation of spherical blast waves in the surrounding air. The focus of this study lay on the effect of the blast waves on the fuel droplets. Blast wave trajectories were investigated by Schlieren imaging. Their interaction with kerosene droplets was obsened with a high speed camera via a long distance microscope; the droplets were visualized by laser-induced Mie scattering. Droplets within a distance of 10 mm fi'om the breakdown position were deformed and disintegrated by the aerodynamic forces of the post shock flow field. Different breakup modes were observed, depending on the distance from the breakdown position: Catastrophic breakup was observed at a 5mm distance, resonant breakup was observed at a 10 mm distance. Breakup by blast waves from ignition sparks is expected to be a crucial mechanism for spray ignition because it supports evaporation. Weber number calculations revealed that the breakup modes obsenvd under lab conditions wilt also appear in aviation gas turbines at high altitude relight conditions.

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Section: Theoretical Considerationsmentioning

confidence: 99%

An Experimental Investigation of Kerosene Droplet Breakup by Laser-Induced Blast Waves

Gebel¹,

Mosbach²,

Meier³

et al. 2013

Journal of Engineering for Gas Turbines and Power

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“…37 Similar to what happened in other Western countries like USA 38 , many farmers struggled for "clean country", that is, they wanted the state to take action against the industrial artificial butter, margarine, which in Denmark had been produced since 1883. 39 The advocators of protectionism sought alliance with the state power. Consequently, in 1885 a motion of a new law was carried with the purpose of guaranteeing export of 'clean' butter, not least to the profitable English market, by requiring that artificial butter should be clearly labeled margarine.…”

Section: Introductionmentioning

confidence: 99%

Associational autonomy or political influence? The case of the cooperation between the Danish Dairies' Buttermark Association and the Danish state, 1900–1912

Svendsen

2013

Business History

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Studies show that it may be risky for business associations to cooperate with the state. Trapped in a dilemma between a 'logic of membership' and a 'logic of influence', these associations may obtain political influence from cooperation but only at the risk of losing their associational autonomy, which often leads to dissatisfaction among members. This article presents an illustrative example of loss of associational autonomy in the context of agricultural corporatism, namely the cooperation between the Buttermark Association and the Danish state on a lawsupported branch trademark for all Danish butter securing high quality and hindering fraudulent sale and adulteration of milki.e., the famous lur brand required by Danish law from 1906 and still in use today.

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Over forty years of continuous research at UTIAS on nonstationary flows and shock waves

Glass

1991

Shock Waves

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Analytical and experimental research on nonsl;ationary shock waves, rarefaction waves and contact surfaces has been conducted continuously at UTIAS since its inception in 1948. Some unique facilities were used to study the properties of planar, cylindrical and spherical shock waves and their interactions. Investigations were also performed on shock-wave structure and boundary layers in ionizing argon, water-vapour condensation in rarefaction waves, magnetogasdynamic flows, and the regions of regular and various types of Mach reflections of oblique shock waves. Explosively-driven implosions have been employed as drivers for projectile launchers and shock tubes, and as a means of producing industrial-type diamonds from graphite, and fusion plasmas in deuterium. The effects of sonic-boom on humans, animals and structures have also formed an important part of the investigations. More recently, interest has focussed on shock waves in dusty gases, the viscous and vibrational structure of weak spherical blast waves in air, and oblique shock-wave reflections. In all of these studies instrumentation and computational methods have played a very important role. A brief survey of this work is given herein and in more detail in the relevant references.

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An Experimental Investigation of Rise Times of Very Weak Shock Waves.

Cited by 4 publications

References 2 publications

An Experimental Investigation of Kerosene Droplet Breakup by Laser-Induced Blast Waves

An Experimental Investigation of Kerosene Droplet Breakup by Laser-Induced Blast Waves

Associational autonomy or political influence? The case of the cooperation between the Danish Dairies' Buttermark Association and the Danish state, 1900–1912

Over forty years of continuous research at UTIAS on nonstationary flows and shock waves

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