scholarly journals Surface Temperature Distribution Characteristics of Marangoni Condensation for Ethanol–Water Mixture Vapor Based on Thermal Infrared Images

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6057
Author(s):  
Guilong Zhang ◽  
Ziqiang Ma ◽  
Heng Li ◽  
Jinshi Wang
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Surface Temperature ◽  
Thermal Infrared ◽  
Water Mixture ◽  
Distribution Characteristics ◽  
Infrared Images ◽  
Single Droplet ◽  
Surface Temperature Distribution ◽  
Thermal Infrared Images

Marangoni condensation is formed due to the surface tension gradient caused by the local temperature or concentration gradient on the condensate surface; thus, the investigation of the surface temperature distribution characteristics is crucial to reveal the condensation mechanism and heat transfer characteristics. Few studies have been conducted on the temperature distribution of the condensate surface. In this study, thermal infrared images were used to measure the temperature distributions of the condensate surface during Marangoni condensation for ethanol–water mixture vapor. The results showed that the surface temperature distribution of the single droplet was uneven, and a large temperature gradient, approximately 15.6 °C/mm, existed at the edge of the condensate droplets. The maximum temperature difference on the droplet surface reached up to 8 °C. During the condensation process, the average surface temperature of a single droplet firstly increased rapidly and then slowly until it approached a certain temperature, whereas that of the condensate surface increased rapidly at the beginning and then changed periodically in a cosine-like curve. The present results will be used to obtain local heat flux and heat transfer coefficients on the condensing surface, and to further establish the relationship between heat transfer and temperature distribution characteristics.

scholarly journals The Feasibility of Identifying Defects Illustrated on Building Facades by Applying Thermal Infrared Images with Shadow

Proceedings ◽  
2019 ◽  
Vol 27 (1) ◽  
pp. 3
Author(s):  
Tsai ◽  
Huang ◽  
Tai
Keyword(s):  
Surface Temperature ◽  
Infrared Thermography ◽  
Infrared Camera ◽  
Thermal Infrared ◽  
Infrared Images ◽  
Building Facades ◽  
Thermal Infrared Images ◽  
Non Destructive

Infrared thermography (IRT) has been widely employed to identify the defects illustrated in building facades. However, the IRT covered with a shadow is hard to be applied to determine the defects shown in the IRT. The study proposed an approach based on the multiplicated model to describe quantitively the shadow effects, and the IRT can be segmented into few classes according to the surface temperature information recorded on the IRT by employing a thermal infrared camera. The segmented results were compared with the non-destructive method (acoustic tracing) to verify the correctness and robustness of the approach. From the processed results, the proposed approach did correctly identify the defects illustrated in building facades through the IRTs were covered with shadow.

scholarly journals Study of ice accretion on wind turbine blade profiles using thermal infrared imaging

2020 ◽  
pp. 0309524X2093394
Author(s):  
Adeel Yousuf ◽  
Jia Yi Jin ◽  
Pavlo Sokolov ◽  
Muhammad S Virk
Keyword(s):  
Temperature Distribution ◽  
Surface Temperature ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Infrared Imaging ◽  
Thermal Infrared ◽  
Ice Accretion ◽  
Blade Profile ◽  
Thermal Infrared Imaging ◽  
Surface Temperature Distribution

Atmospheric icing has been recognized as hindrance in proper utilization of good wind resources in cold regions. There is a growing need to better understand the ice accretion physics along wind turbine blades to improve its performance and for optimal design of anti/de-icing system. This article describes a study of ice accretion along wind turbine blade profiles using thermal infrared imaging. Surface temperature distribution along four different blade profile surfaces is studied at different operating conditions. Analysis shows that surface temperature distribution along blade profile surface during ice accretion process is a dynamic process and change in atmospheric conditions and blade geometric characteristics significantly affects the surface temperature and resultant ice accretion. The effect of blade geometry on ice accretion is more prominent in case of wet ice conditions due to low freezing fraction and water run back along blade profile surface.

Shroud Heat Transfer Measurements From a Rotating Cavity With an Axial Throughflow of Air

1994 ◽  
Vol 116 (3) ◽  
pp. 525-534 ◽  
Author(s):  
C. A. Long ◽  
P. G. Tucker
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Surface Temperature ◽  
Vortex Breakdown ◽  
Rossby Number ◽  
Temperature Level ◽  
Centripetal Acceleration ◽  
Surface Temperature Distribution ◽  
Nusselt Numbers ◽  
Rotating Cavity

The paper discusses measurements of heat transfer obtained from the inside surface of the peripheral shroud. The experiments were carried out on a rotating cavity, comprising two 0.985-m-dia disks, separated by an axial gap of 0.065 m and bounded at the circumference by a carbon fiber shroud. Tests were conducted with a heated shroud and either unheated or heated disks. When heated, the disks had the same temperature level and surface temperature distribution. Two different temperature distributions were tested; the surface temperature either increased, or decreased with radius. The effects of disk, shroud, and air temperature levels were also studied. Tests were carried out for the range of axial throughflow rates and speeds: 0.0025 ≤ m ≤ 0.2 kg/s and 12.5 ≤Ω≤ 125 rad/s, respectively. Measurements were also made of the temperature of the air inside the cavity. The shroud Nusselt numbers are found to depend on a Grashof number, which is defined using the centripetal acceleration. Providing the correct reference temperature is used, the measured Nusselt numbers also show similarity to those predicted by an established correlation for a horizontal plate in air. The heat transfer from the shroud is only weakly affected by the disk surface temperature distribution and temperature level. The heat transfer from the shroud appears to be affected by the Rossby number. A significant enhancement to the rotationally induced free convection occurs in the regions 2≤Ro≤4 and Ro≥20. The first of these corresponds to a region where vortex breakdown has been observed. In the second region, the Rossby number may be sufficiently large for the central throughflow to affect the shroud heat transfer directly. Heating the shroud does not appear to affect the heat transfer from the disks significantly.

Use of Analytical Expressions of Convection in Conjugated Heat Transfer Problems

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
R. Karvinen
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Surface Temperature ◽  
Flow Direction ◽  
Superposition Principle ◽  
Industrial Applications ◽  
Transfer Coefficients ◽  
Flat Plates ◽  
Surface Temperature Distribution ◽  
Analytical Expressions

The heat transfer coefficient of convection from the wall to the flow depends on flow type, on surface temperature distribution in a stream-wise direction, and in transient cases also on time. In so-called conjugated problems, the surface temperature distribution of the wall and flow are coupled together. Thus, the simultaneous solution of convection between the flow and wall, and conduction in the wall are required because heat transfer coefficients are not known. For external and internal flows, very accurate approximate analytical expressions have been derived for heat transfer in different kinds of boundary conditions which change in flow direction. Due to the linearity of the energy equation, the superposition principle can be adopted to couple with these expressions the surface temperature and heat flux distributions in conjugated problems. In the paper, this type of approach is adopted and applied to a number of industrial applications ranging from flat plates of electroluminecence displays to the optimization of heat transfer in fins, fin arrays and mobile phones.

scholarly journals Summer surface temperature distribution analysis of Mykolayiv city based on the Landsat series thermal infrared data

2019 ◽  
pp. 49-59 ◽  
Author(s):  
Lyidmila Lischenko ◽  
Natalia Pazynych ◽  
Volodymyr Filipovych
Keyword(s):  
Temperature Distribution ◽  
Surface Temperature ◽  
Residential Building ◽  
Thermal Anomaly ◽  
Thermal Infrared ◽  
Temporal Variations ◽  
Distribution Analysis ◽  
Surface Temperature Distribution ◽  
The City ◽  
Infrared Data

The surface temperature distribution analysis of the condition and characteristics within one of the industrial centers of the south of Ukraine, Mykolaiv, from 1985 to 2018 was carried out on the basis of Landsat thermal infrared data processing. Temporal development of surface temperature distribution was investigated both for the entire territory of the city and for individual profiles crossing the diverse landscape and functional city areas. Significant surface temperature distribution divergences during temporal variations in different, but steady landscapes and functional conditions have been stated. Abnormally high temperatures are found within industrial zones, reaching 40–43оC. The water temperatures of the Southern Bug, Ingula and Lake Liski are the lowest and are determined by the amount of water mass. The highest temperature oscillation (up to 15oC) during the research period, was recorded on the artificially aggradated sands within floodplain of the Southern Bug, after the residential building “Namyv” was built and within the “Zhovtneve” reservoir, after its draining. The main types of residential development of the city — a medium, low-rise buildings and private cottages surrounded by trees and lawns, forming a stable temperature background. Limited distribution of impermeable surfaces, significant planting, intensive watering resulted in the formation of a negative thermal anomaly within the city, a peculiar cool oasis against a hot background of steppe agro-landscapes.

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