Abel inversion of axially-symmetric shock wave flows

Houwing, A. F. P.; Takayama, K.; Jiang, Zonglin; Hashimoto, Tokitada; Koremoto, Kensuke; Mitobe, Hiroyuki; Gaston, M.

doi:10.1007/s00193-005-0244-y

Cited by 6 publications

(3 citation statements)

References 7 publications

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“…This mathematical analysis extracts the density as a function of radius from a single interferogram. Flows over spheres and cones have been studied in hypersonic flows clearly demonstrating the applicability of the technique (42) . For more complicated flows, it is necessary to resort to multiple imaging from various angles -the more images recorded, the more accurate the technique.…”

Section: Recent Advancesmentioning

confidence: 92%

Optical imaging techniques for hypersonic impulse facilities

2007

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The application of optical imaging techniques to hypersonic facilities is discussed and examples of experimental measurements are provided. Traditional Schlieren and shadowgraph techniques still remain as inexpensive and easy to use flow visualisation techniques. With the advent of faster cameras, these methods are becoming increasingly important for time-resolved high-speed imaging. Interferometry’s quantitative nature is regularly used to obtain density information about hypersonic flows. Recent developments have seen an extension of the types of flows that can be imaged and the measurement of other flow parameters such as ionisation level. Planar laser induced fluorescence has been used to visualise complex flows and to measure such quantities as temperature and velocity. Future directions for optical imaging are discussed.

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Section: Recent Advancesmentioning

confidence: 92%

Optical imaging techniques for hypersonic impulse facilities

2007

Self Cite

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“…First, a two-dimensional fast Fourier transform of the interferogram is performed to select the appropriate frequency domain used to apply a bandpass filter to a two-dimensional inverse fast Fourier transform. This treatment allows us to remove lowfrequency and high-frequency noise from the data [12]. Then, the phase values (in the range [−π, +π ]) are determined by evaluating the arctangent of the ratio of the imaginary and real parts of the inverse transform.…”

Section: Interferogram Processingmentioning

confidence: 99%

Check of OH rotational temperature using an interferometric method

Rabat

Izarra

2004

J. Phys. D: Appl. Phys.

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This paper presents an interferometric method used to check the rotational temperature of the OH free radical obtained using emission spectroscopy. The temperature is extracted from an interferogram via the phase shifting introduced by the refractive index of the studied medium. The refractive index is related to the temperature through the Gladstone–Dale equation and the ideal gas law.The method is tested on the laminar premixed flame of an oxy-acetylene burner and on the laminar plume of a dc argon plasma torch. The results obtained are compared with those obtained from the UV OH band at 306.357 nm (transition A2Σ, ν = 0 → X2Π, ν′ = 0) by emission spectroscopy using the Boltzmann plot method and using a method based on numerical simulated spectra with the amplitude ratios of groups of unresolved rotational lines.

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“…The relieving pressureis set by the initial compression of the spring which can be altered through the adjusting gland (4). Minor modications have been applied to the valve to facilitate the experimental work; a 4 mm diameter rod 150 mm long has been tted to the piston rear, the adjusting gland (4) and the adjusting gland insert(5) have been combined and replaced by a single equivalent component and the spring(7) has been cut to a smaller length. The rod diameter is less than the spring inner diameter, so there is no signicant change in the ow area at this region.…”

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confidence: 99%

Computational Fluid Dynamics Investigations of Shock Waves in Safety Relief Valves

Elmayyah

2013

International Conference on Aerospace Sciences and Aviation Tec

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Safety Relief Valves plays an important role in any pressurised system. The proper design of safety relief valves should consider the eective opening and closing characteristics to achieve the desired valve performance. One of the challenges in any valve design is the elimination of Shock waves. Shock waves are characterised by sudden pressure increase and Mach number drop. Detecting shock waves in safety relief valves using computational uid dynamics could asses valve design to eliminate the shock waves. I t have been proven that the Reynolds Averaged Navier Stocks (RANS) equations with the k-turbulence model could model the internal gas ow in safety relief valves. The RANS and k-turbulence have been solved by a commercial CFD code. In safety valves discharge ow rate and closing and opening behaviours depend on the upstream pressure and certain critical areas. In this study, the eect of the upstream pressure has been discussed. Upstream pressure range was from 7 to 140 bars. The eect of the valve geometry has been discussed as well. Dierent critical outlet areas and divergent angles have been changed to investigate its eect on the shock wave parameters. The upstream pressure eect on shock wave occurrence and intensity have been studied. The results showed that, computational uid dynamics can be used to predict the location of the shock wave. In addition to determining the pressure peak and the Mach number drop and other properties which help eliminating shock wave occurrence in valve design. An ecient design should consider the geometrical and ow parameters that aect the shock wave occurrence and intensity.

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Abel inversion of axially-symmetric shock wave flows

Cited by 6 publications

References 7 publications

Optical imaging techniques for hypersonic impulse facilities

Optical imaging techniques for hypersonic impulse facilities

Check of OH rotational temperature using an interferometric method

Computational Fluid Dynamics Investigations of Shock Waves in Safety Relief Valves

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