scholarly journals Changes of water temperature and heat flux at water-sediment interface, East Lake Taihu

2018 ◽  
Vol 30 (6) ◽  
pp. 1599-1609 ◽  
Author(s):  
ZENG Ye ◽  
◽  
ZHU Jinge ◽  
WANG Yanping ◽  
HU Weiping
Keyword(s):  
Heat Flux ◽  
Water Temperature ◽  
Lake Taihu ◽  
East Lake ◽  
Sediment Interface

Water temperature and heat flux at the base of river ice covers

1987 ◽  
Vol 14 (1) ◽  
pp. 33-50 ◽  
Author(s):  
Philip Marsh ◽  
Terry D Prowse
Keyword(s):  
Heat Flux ◽  
Water Temperature ◽  
River Ice

Effect of Water Temperature on Spray Cooling Heat Transfer on Hot Steel Plate

2010 ◽  
Author(s):  
Jungho Lee ◽  
Cheong-Hwan Yu ◽  
Sang-Jin Park
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Water Temperature ◽  
Steel Plate ◽  
Cooling Water ◽  
Local Heat ◽  
Spray Cooling ◽  
Transfer Coefficients ◽  
Cooling Water Temperature ◽  
Local Heat Flux

Water spray cooling is an important technology which has been used in a variety of engineering applications for cooling of materials from high-temperature nominally up to 900°C, especially in steelmaking processes and heat treatment in hot metals. The effects of cooling water temperature on spray cooling are significant for hot steel plate cooling applications. The local heat flux measurements are introduced by a novel experimental technique in which test block assemblies with cartridge heaters and thermocouples are used to measure the heat flux distribution on the surface of hot steel plate as a function of heat flux gauge. The spray is produced from a fullcone nozzle and experiments are performed at fixed water impact density of G and fixed nozzle-to-target spacing. The results show that effects of water temperature on forced boiling heat transfer characteristics are presented for five different water temperatures between 5 to 45°C. The local heat flux curves and heat transfer coefficients are also provided to a benchmark data for the actual spray cooling of hot steel plate cooling applications.

Two Large-Amplitude/Long-Period Oscillating Boiling Modes in Silicon Microchannels

2003 ◽  
Author(s):  
H. Y. Wu ◽  
Ping Cheng
Keyword(s):  
Heat Flux ◽  
Water Temperature ◽  
Large Amplitude ◽  
Two Phase Flow ◽  
Flow Boiling ◽  
Bubbly Flow ◽  
Saturation Temperature ◽  
Phase Flow ◽  
Two Phase ◽  
Long Period

A simultaneous visualization and measurement study has been carried out to investigate flow boiling of water in the 8 parallel silicon microchannels heated from below. It is found that there are two large-amplitude/long-period oscillating boiling modes exist in microchannels depending on the amounts of heat flux and mass flux. When the outlet water temperature is at saturation temperature and the wall temperatures are superheated, while the inlet water temperature is still subcooled, a Liquid/Two-phase Alternating Flow (LTAF) mode appears in the microchannels. This LTAF mode disappears when the inlet temperatures reaches the saturation temperature. As the heat flux is further increased such that the outlet water is superheated while the inlet water temperature is oscillating between subcooled and saturation temperature, a Liquid/Two-phase/Vapor Alternating Flow (LTVAF) mode begins. During these two unstable boiling modes, there are large-amplitude and long-period oscillations of water and wall temperatures with respect to time. Bubbly flow as well as some peculiar two-phase flow pattern are observed during the two-phase flow periods of the two unstable modes in the microchannels.

scholarly journals Field Results from a Second-Generation Ocean/Lake Surface Contact Heat Flux, Solar Irradiance, and Temperature Measurement Instrument—The Multisensor Float

2007 ◽  
Vol 24 (5) ◽  
pp. 856-876 ◽  
Author(s):  
J. P. Boyle
Keyword(s):  
Heat Flux ◽  
Water Temperature ◽  
Temperature Measurement ◽  
Solar Irradiance ◽  
Second Generation ◽  
Flux Measurement ◽  
Eddy Correlation ◽  
Near Surface ◽  
Surface Contact ◽  
Good Agreement

Abstract This paper describes results from two field programs that support development of a wave-following surface contact multisensor float (MSF) designed to simultaneously measure net surface heat flux, net solar irradiance, and water temperature. The results reported herein compare measurements from a second-generation design (circa 1998) against directly measured radiative fluxes as well as turbulent fluxes derived using both eddy correlation and bulk aerodynamic methods. The reference flux data are collected using instrumented towers, buoys, and research vessels. Comparisons show that MSF net surface fluxes and net solar irradiance are in generally good agreement with values that are measured or derived using standard instruments and methods, having root-mean-square differences less than approximately 15%. MSF near-surface bulk water temperature measurement shows good agreement with similar measurements from a drifting buoy. MSF measurement of water surface temperature is not definitively determined, although results suggest it may be a good measure of skin temperature at night. MSF flux measurement occurs from within the aqueous conductive sublayer and so does not use turbulence models or parameterizations. At this time, results are most reliable in low wind conditions (2 m s−1 ≤ U10 ≤ 7 m s−1) and relatively calm seas. In higher winds and more active seas, the imperfect surface drifting and wave-following characteristics of the second-generation system limit its performance. More fundamentally, perturbation to the aqueous conductive sublayer and modification of near-surface turbulence structure by the MSF may also limit flux measurement accuracy under certain conditions.

scholarly journals Heat flux, water temperature and discharge from 15 northern Canadian rivers draining to Arctic Ocean and Hudson Bay

2021 ◽  
pp. 103577
Author(s):  
Daqing Yang ◽  
Rajesh R. Shrestha ◽  
Joanna Li Yung Lung ◽  
Suzanne Tank ◽  
Hotaek Park
Keyword(s):  
Heat Flux ◽  
Water Temperature ◽  
Arctic Ocean ◽  
Hudson Bay

scholarly journals Relative impacts of increases of solar radiation and air temperature on the temperature of surface water in a shallow, eutrophic lake

2021 ◽  
Author(s):  
Ryuichiro Shinohara ◽  
Yoji Tanaka ◽  
Ariyo Kanno ◽  
Kazuo Matsushige
Keyword(s):  
Heat Flux ◽  
Surface Water ◽  
Solar Radiation ◽  
Water Temperature ◽  
Air Temperature ◽  
Heat Fluxes ◽  
Shortwave Radiation ◽  
Surface Water Temperature ◽  
Lake Kasumigaura ◽  
Lake Surface

Abstract We monitored lake surface water temperatures from 1992 to 2019 in Lake Kasumigaura, a shallow lake in Japan. We hypothesized that increases of shortwave radiation had increased surface water temperatures and heat fluxes more than had the increases of air temperature. We used the heat flux analyses and the sensitivity analyses to test the hypothesis. The fluxes of solar radiation gradually increased during the study period in a manner consistent with the phenomenon of global brightening. The increase was especially apparent in the spring. The rate of increase of surface water temperature was especially significant in May. Air temperature did not significantly increase in May, but it increased significantly in June (0.40 °C decade−1). A sensitivity analysis of the heat fluxes at the lake surface (shortwave radiation, longwave radiation, latent heat flux, and sensible heat flux) revealed that surface water temperature was more sensitive to changes of shortwave radiation than to air temperature during the spring. Although other factors such as inflows of groundwater and river water may also have impacted surface water temperatures, the increase of solar radiation appeared to be the major factor responsible for the increase of surface water temperature during the spring in Lake Kasumigaura.

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