The Anomalous Behavior of Oscillatory Temperature Fluctuations near the Threshold of Thermal Convection

1976 ◽  
Vol 40 (1) ◽  
pp. 280-285 ◽  
Author(s):  
Yoshimi Tsuchiya
Keyword(s):  
Thermal Convection ◽  
Temperature Fluctuations ◽  
Anomalous Behavior ◽  
Oscillatory Temperature

scholarly journals The causes of atmospheric inhomogeneities

1963 ◽  
Vol 19 ◽  
pp. 132-143 ◽  
Author(s):  
R. S. Scorer
Keyword(s):  
Thermal Convection ◽  
Pressure Fluctuations ◽  
Temperature Fluctuations ◽  
Stable Layer ◽  
Free Air

There are several different atmospheric causes, of imperfections in the images seen in a telescope. The most serious are due to thermal convection from the ground, or the stirring of a stable layer at the ground by wind : choice of site and observatory design can reduce these effects. In the free air well away from the ground some of the largest inhomogeneities may be due essentially to large gradients of humidity, and certain cloud types indicate the mechanisms by which such inhomogeneities are established. Temperature fluctuations caused by pressure fluctuations in eddies close to the telescope are probably not serious, and can be avoided by observatory design.

scholarly journals Effects of rotation on temperature fluctuations in turbulent thermal convection on a hemisphere

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
T. Meuel ◽  
M. Coudert ◽  
P. Fischer ◽  
C. H. Bruneau ◽  
H. Kellay
Keyword(s):  
Thermal Convection ◽  
Temperature Fluctuations ◽  
Effects Of Rotation

Multi-point local temperature measurements inside the conducting plates in turbulent thermal convection

2007 ◽  
Vol 570 ◽  
pp. 479-489 ◽  
Author(s):  
CHAO SUN ◽  
KE-QING XIA
Keyword(s):  
Thermal Convection ◽  
Large Scale ◽  
Time Derivative ◽  
Temperature Fluctuations ◽  
Local Temperature ◽  
Maximum Temperature ◽  
Convection Cell ◽  
Scaling Properties ◽  
Plume Emission ◽  
Plume Clusters

An experimental study of local temperature statistics in turbulent thermal convection is presented. The emissions of plumes and plume clusters are detected by an array of thermistors embedded in the top and bottom plates of a 1 m diameter convection cell. We found that the product STST′ of the temperature skewness ST and the skewness of the temperature time derivative ST′ from the embedded thermistors may be used as a measure of the intensity of plume emissions and that STST′ exhibits a pattern that corresponds well to the orientation of the large-scale circulation in the convecting flow. This is despite the fact that the temperature distribution across the plates is highly uniform, as indicated by the mean temperature of the embedded thermistors. By comparing the spatial distributions of STST′ and of the RMS temperature σ, we further find that the maximum temperature fluctuations take place in regions dominated by plume mixing instead of regions of plume emission. It is also found that temperature fluctuations inside the conducting plates have the same statistical and scaling properties as those in the cell centre.

A Continuous Boiling Model for Face Seals

1990 ◽  
Vol 112 (2) ◽  
pp. 266-274 ◽  
Author(s):  
J. A. Yasuna ◽  
W. F. Hughes
Keyword(s):  
Laminar Flow ◽  
Phase Change ◽  
Thermal Convection ◽  
Experimental Verification ◽  
Numerical Solutions ◽  
Narrow Range ◽  
Anomalous Behavior ◽  
Adiabatic Flow ◽  
Low Leakage ◽  
Face Seals

Mechanical face seals with phase change have extensive engineering applications, yet little theory exists to predict dynamic and thermodynamic behavior. At present, numerical solutions exist for two operating extremes—for low leakage laminar flow where boiling is assumed to occur discretely, and for high leakage, turbulent adiabatic flow. A model is presented herein which allows for continuous boiling, and considers thermal convection effects in laminar flow. Sample calculations and results are compared to the discrete boiling model, and as leakage increases and convection effects become more important boiling may occur over a large portion of the seal face. It is shown that contrary to the discrete boiling model, there may exist a narrow range of stable or bistable operation even when saturation conditions exist near the seal inlet. Instability will invariably occur however if the seal is sufficiently perturbed. This analysis is intended to explain some of the anomalous behavior observed in typical sealing applications, and to act as a guide for experimental verification.

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