Radiative Cooling of Shock-Heated Air in an Explosively Driven Shock Tube

David M. Cooper

doi:10.1063/1.1693751

Radiative Cooling of a Hydrogen Plasma in a Shock Tube

AIAA Journal ◽

10.2514/3.61381 ◽

1976 ◽

Vol 14 (4) ◽

pp. 421-426 ◽

Cited By ~ 2

Author(s):

George H. Stickford

Keyword(s):

Shock Tube ◽

Hydrogen Plasma ◽

Radiative Cooling

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Radiative cooling of shock-heated air in cylindrical shock tubes

AIAA Journal ◽

10.2514/3.6017 ◽

1970 ◽

Vol 8 (10) ◽

pp. 1896-1898 ◽

Cited By ~ 4

Author(s):

KUEI-YUAN CHIEN ◽

DALE L. COMPTON

Keyword(s):

Radiative Cooling ◽

Shock Tubes ◽

Heated Air

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Radiative cooling of a hydrogen plasma in a shock tube

10.2514/6.1975-40 ◽

1975 ◽

Cited By ~ 2

Author(s):

G. STICKFORD, JR.

Keyword(s):

Shock Tube ◽

Hydrogen Plasma ◽

Radiative Cooling

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Time-Averaged Heat-Flux Distributions and Comparison With Prediction for the Teledyne 702 HP Turbine Stage

Journal of Turbomachinery ◽

10.1115/1.3262167 ◽

1988 ◽

Vol 110 (1) ◽

pp. 51-56 ◽

Cited By ~ 6

Author(s):

M. G. Dunn ◽

R. E. Chupp

Keyword(s):

Thin Film ◽

Heat Flux ◽

Shock Tube ◽

Flat Plate ◽

Leading Edge ◽

Turbine Stage ◽

Heated Air ◽

Edge Distribution ◽

Flux Measurements ◽

Good Agreement

Time-averaged heat-flux distributions are reported for the vane and blade of the Teledyne CAE 702 HP full-stage rotating turbine. A shock tube is used as a short-duration source of heated air to which the turbine is subjected and thin-film gages are used to obtain the heat-flux measurements. The thin-film gages were concentrated on the midspan region from the leading edge to near the trailing edge. The blade contained two contoured inserts wtih gages spaced very close together so that the leading edge distribution could be resolved. The NGV and blade results are compared with predictions obtained using a flat-plate technique, an eddy-diffusing model (STAN 5), and a k–ε model. The results of the comparison between data and prediction suggest that: (a) first, the vane data are bounded by the turbulent flat plate and the fully turbulent STAN 5 prediction. For the vane, the k–ε prediction is in relatively good agreement with the STAN 5 prediction and (b) secondly, the blade data are acceptably predicted by the k–ε prediction on both the pressure and the suction surfaces. The STAN 5 fully turbulent calculation for the blade falls above the data (essentially in agreement with the turbulent flat-plate calculation) and the STAN 5 fully laminar falls substantially below the data. With the exception of the pressure loadings and the geometry, the code inputs used for these predictions were identical to those previously used to predict the Garrett TFE 731-2 HP turbine and the Garrett LART HP turbine.

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Saturation mechanism and generated viscosity in gravito-turbulent accretion disks

Astronomy and Astrophysics ◽

10.1051/0004-6361/202038023 ◽

2020 ◽

Vol 640 ◽

pp. A53

Author(s):

L. Löhnert ◽

S. Krätschmer ◽

A. G. Peeters

Keyword(s):

Growth Rate ◽

Numerical Simulations ◽

Accretion Disks ◽

Gravitational Instability ◽

Turbulent Viscosity ◽

Radial Distance ◽

Maximum Growth ◽

Wave Number ◽

Radiative Cooling ◽

Mixing Length

Here, we address the turbulent dynamics of the gravitational instability in accretion disks, retaining both radiative cooling and irradiation. Due to radiative cooling, the disk is unstable for all values of the Toomre parameter, and an accurate estimate of the maximum growth rate is derived analytically. A detailed study of the turbulent spectra shows a rapid decay with an azimuthal wave number stronger than ky−3, whereas the spectrum is more broad in the radial direction and shows a scaling in the range kx−3 to kx−2. The radial component of the radial velocity profile consists of a superposition of shocks of different heights, and is similar to that found in Burgers’ turbulence. Assuming saturation occurs through nonlinear wave steepening leading to shock formation, we developed a mixing-length model in which the typical length scale is related to the average radial distance between shocks. Furthermore, since the numerical simulations show that linear drive is necessary in order to sustain turbulence, we used the growth rate of the most unstable mode to estimate the typical timescale. The mixing-length model that was obtained agrees well with numerical simulations. The model gives an analytic expression for the turbulent viscosity as a function of the Toomre parameter and cooling time. It predicts that relevant values of α = 10−3 can be obtained in disks that have a Toomre parameter as high as Q ≈ 10.

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