Surface heat flux, horizontal advection, and the seasonal evolution of water temperature on the Scotian Shelf

1994 ◽  
Vol 99 (C10) ◽  
pp. 20403 ◽  
Author(s):  
Joseph U. Umoh ◽  
Keith R. Thompson
Keyword(s):  
Heat Flux ◽  
Water Temperature ◽  
Surface Heat Flux ◽  
Surface Heat ◽  
Scotian Shelf ◽  
Horizontal Advection ◽  
Seasonal Evolution

scholarly journals Seasonal and Interannual Variations of the SST above the Seychelles Dome

2012 ◽  
Vol 25 (2) ◽  
pp. 800-814 ◽  
Author(s):  
Takaaki Yokoi ◽  
Tomoki Tozuka ◽  
Toshio Yamagata
Keyword(s):  
Heat Flux ◽  
Seasonal Variation ◽  
Mixed Layer ◽  
Surface Heat Flux ◽  
Surface Heat ◽  
Shortwave Radiation ◽  
Interannual Variations ◽  
Vertical Diffusion ◽  
Horizontal Advection ◽  
Seasonal And Interannual Variations

Abstract The seasonal and interannual variations of the sea surface temperature (SST) above the Seychelles Dome (SD) are investigated using outputs from an OGCM. The SST warms from August to April and cools from May to July. The surface heat flux plays the most important role in the seasonal variation, and it is mostly due to shortwave radiation. The horizontal advection tends to warm the SST in austral winter owing to the southward Ekman heat transport associated with the Indian summer monsoon. The cooling by the vertical turbulent diffusion becomes most effective in austral summer owing to the thin mixed layer during that time. On the interannual time scale, the SST becomes anomalously warm (cool) when the SD is weak (strong). In contrast to the seasonal variation, the vertical diffusion plays the most important role and causes anomalous warming (cooling). This warming (cooling) is due to the anomalously warm (cold) water below the mixed layer as a result of the deeper (shallower) thermocline in response to ocean dynamics. Also, the cooling by the vertical diffusion becomes less (more) efficient, because the mixed layer is anomalously thick (thin). The horizontal advection contributes to the anomalous warming (cooling) due to the anomalous southward (northward) Ekman heat transport. On the other hand, the anomalous surface heat flux tends to cool (warm) the mixed layer, because the warming of the mixed layer by the shortwave radiation becomes less (more) efficient due to the anomalously thick (thin) mixed layer.

scholarly journals Mixed Layer Heat Variations in the South China Sea Observed by Argo Float and Reanalysis Data during 2012–2015

2019 ◽  
Vol 11 (19) ◽  
pp. 5429 ◽  
Author(s):  
Liang ◽  
Xing ◽  
Wang ◽  
Zeng
Keyword(s):  
Heat Flux ◽  
South China Sea ◽  
Mixed Layer ◽  
South China ◽  
Surface Heat Flux ◽  
Heat Budget ◽  
Surface Heat ◽  
Horizontal Advection ◽  
Net Heat Flux ◽  
Mixed Layer Heat Budget

The atmospheric and oceanic causes of mixed layer heat variations in the South China Sea (SCS) are examined using data from six long-lived Array for Real-time Geostrophic Oceanography (Argo) floats. The mixed layer heat budget along each float trajectory is evaluated based on direct measurements, satellite and reanalysis datasets. Our results suggest that the mixed layer heat balance in the SCS has distinct spatial and seasonal variations. The amplitude of all terms in the mixed layer heat budget equation is significantly larger in the northern SCS than in the southern SCS, especially in winter. In the northern SCS, the mixed layer heat budget is controlled by the local surface heat flux and horizontal advection terms in winter, and the net heat flux term in summer. In the western and southeastern SCS, the mixed layer heat budget is dominated by the net surface heat flux in both winter and summer. Further analysis shows that in the SCS, surface shortwave radiation and geostrophic heat advection are major contributors to net heat flux and horizontal advection, respectively. Unlike the net heat flux and horizontal advection, the vertical entrainment is a sink term in general. The rate of mixed layer deepening is the most important factor in the entrainment rate, and a barrier layer may decrease the temperature difference between the bottom of the mixed layer and the water beneath. Residual analysis suggests that the residual term in the equation is due to the inexact calculation of heat geostrophic advection, other missing terms, and unresolved physical ocean dynamic processes.

Effect of Water Temperature on Wetting Front Kinematics during Forced Convective Quenching

2012 ◽  
Vol 706-709 ◽  
pp. 1415-1420 ◽  
Author(s):  
Bernie Hernández-Morales ◽  
Juan Ramón González-López ◽  
Gildardo Solorio-Díaz ◽  
Héctor Javier Vergara-Hernández
Keyword(s):  
Heat Flux ◽  
Water Temperature ◽  
Surface Heat Flux ◽  
Nucleate Boiling ◽  
Surface Heat ◽  
Front Velocity ◽  
Wetting Front ◽  
Probe Surface ◽  
Effect Of Water ◽  
Video Recordings

The kinematics of the wetting front, i.e., the history of the locus of the boundary between the vapor blanket and the nucleate boiling area is of outmost importance in quenching operations. In this investigation, the effect of water temperature on the wetting front kinematics was studied in forced convective quenching experiments of conical-end cylindrical probes. Three values of water temperature (30, 45 and 60 °C) were studied for a free-stream water velocity of 0.2 m/s. The wetting front kinematics was characterized from: 1) the measured thermal response at three longitudinal positions inside the probe, near the probe surface, and 2) high-speed video-recordings of the events that took place at the probe surface upon quenching. From the video-recordings, the position of the wetting front as a function of time was determined to estimate the wetting front velocity from a linear regression. The wetting front velocity was constant for a given experiment and increased as the water temperature decreased. The bubble size decreased and the frequency of bubble formation increased as the water temperature decreased. Using the measured thermal responses, the surface heat flux history was estimated, solving the corresponding inverse heat conduction problem. A regression analysis was applied to relate the maximum (critical) surface heat flux and the water temperature as a first step towards modeling the surface heat flux history as a function of water temperature.

Analysis of significant measures for thermal conductivity

2020 ◽  
pp. 35-42
Author(s):  
Yuri P. Zarichnyak ◽  
Vyacheslav P. Khodunkov
Keyword(s):  
Thermal Conductivity ◽  
Heat Flux ◽  
Surface Heat Flux ◽  
Heat Flux Density ◽  
Measurement Method ◽  
Conductivity Measurement ◽  
Surface Heat ◽  
Measuring Instrument ◽  
New Class ◽  
Achievable Accuracy

The analysis of a new class of measuring instrument for heat quantities based on the use of multi-valued measures of heat conductivity of solids. For example, measuring thermal conductivity of solids shown the fallacy of the proposed approach and the illegality of the use of the principle of ambiguity to intensive thermal quantities. As a proof of the error of the approach, the relations for the thermal conductivities of the component elements of a heat pump that implements a multi-valued measure of thermal conductivity are given, and the limiting cases are considered. In two ways, it is established that the thermal conductivity of the specified measure does not depend on the value of the supplied heat flow. It is shown that the declared accuracy of the thermal conductivity measurement method does not correspond to the actual achievable accuracy values and the standard for the unit of surface heat flux density GET 172-2016. The estimation of the currently achievable accuracy of measuring the thermal conductivity of solids is given. The directions of further research and possible solutions to the problem are given.

Heat Transfer Characteristics of Downward Facing Hot Horizontal Surfaces Using Mist Jet Impingement

2017 ◽  
Author(s):  
Ashutosh Kumar Yadav ◽  
Parantak Sharma ◽  
Avadhesh Kumar Sharma ◽  
Mayank Modak ◽  
Vishal Nirgude ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Surface Heat Flux ◽  
Cooling System ◽  
Water Pressure ◽  
Jet Impingement ◽  
Surface Heat ◽  
Heat Transfer Characteristics ◽  
Impingement Cooling ◽  
Transfer Characteristics

Impinging jet cooling technique has been widely used extensively in various industrial processes, namely, cooling and drying of films and papers, processing of metals and glasses, cooling of gas turbine blades and most recently cooling of various components of electronic devices. Due to high heat removal rate the jet impingement cooling of the hot surfaces is being used in nuclear industries. During the loss of coolant accidents (LOCA) in nuclear power plant, an emergency core cooling system (ECCS) cool the cluster of clad tubes using consisting of fuel rods. Controlled cooling, as an important procedure of thermal-mechanical control processing technology, is helpful to improve the microstructure and mechanical properties of steel. In industries for heat transfer efficiency and homogeneous cooling performance which usually requires a jet impingement with improved heat transfer capacity and controllability. It provides better cooling in comparison to air. Rapid quenching by water jet, sometimes, may lead to formation of cracks and poor ductility to the quenched surface. Spray and mist jet impingement offers an alternative method to uncontrolled rapid cooling, particularly in steel and electronics industries. Mist jet impingement cooling of downward facing hot surface has not been extensively studied in the literature. The present experimental study analyzes the heat transfer characteristics a 0.15mm thick hot horizontal stainless steel (SS-304) foil using Internal mixing full cone (spray angle 20 deg) mist nozzle from the bottom side. Experiments have been performed for the varied range of water pressure (0.7–4.0 bar) and air pressure (0.4–5.8 bar). The effect of water and air inlet pressures, on the surface heat flux has been examined in this study. The maximum surface heat flux is achieved at stagnation point and is not affected by the change in nozzle to plate distance, Air and Water flow rates.

scholarly journals Nanofluid Flow on a Shrinking Cylinder with Al2O3 Nanoparticles

Mathematics ◽  
2021 ◽  
Vol 9 (14) ◽  
pp. 1612
Author(s):  
Iskandar Waini ◽  
Anuar Ishak ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Friction Factor ◽  
Surface Heat Flux ◽  
Transfer Rate ◽  
Surface Heat ◽  
Al2o3 Nanoparticles ◽  
Nanofluid Flow ◽  
Curvature Parameter ◽  
Over Time

This study investigates the nanofluid flow towards a shrinking cylinder consisting of Al2O3 nanoparticles. Here, the flow is subjected to prescribed surface heat flux. The similarity variables are employed to gain the similarity equations. These equations are solved via the bvp4c solver. From the findings, a unique solution is found for the shrinking strength λ≥−1. Meanwhile, the dual solutions are observed when λc<λ<−1. Furthermore, the friction factor Rex1/2Cf and the heat transfer rate Rex−1/2Nux increase with the rise of Al2O3 nanoparticles φ and the curvature parameter γ. Quantitatively, the rates of heat transfer Rex−1/2Nux increase up to 3.87% when φ increases from 0 to 0.04, and 6.69% when γ increases from 0.05 to 0.2. Besides, the profiles of the temperature θ(η) and the velocity f’(η) on the first solution incline for larger γ, but their second solutions decline. Moreover, it is noticed that the streamlines are separated into two regions. Finally, it is found that the first solution is stable over time.

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