Simultaneous Measurement of Dry Patch Behavior and Surface Temperature Distribution for Copper Heat Transfer Surface with Deposition Layer in Nucleate Pool Boiling

2018 ◽  
Vol 2018 (0) ◽  
pp. 0111
Author(s):  
Shinichiro Uesawa ◽  
Ayako Ono ◽  
Yasuo Koizumi ◽  
Mitsuhiko Shibata ◽  
Hiroyuki Yoshida
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Surface Temperature ◽  
Simultaneous Measurement ◽  
Pool Boiling ◽  
Heat Transfer Surface ◽  
Nucleate Pool Boiling ◽  
Surface Temperature Distribution ◽  
Dry Patch

Study on Nucleate Boiling Heat Transfer by Measuring Detailed Surface Temperature Distribution and Variation With Infrared Radiation Camera

2014 ◽  
Author(s):  
Kazuki Takahashi ◽  
Yasuo Koizumi
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Temperature Distribution ◽  
Surface Temperature ◽  
Infrared Radiation ◽  
Boiling Heat Transfer ◽  
Pool Boiling ◽  
Heat Transfer Surface ◽  
Bubble Generation ◽  
Test Vessel

Pool boiling heat transfer experiments were performed for water at 101 kPa to examine elementary process of nucleate pool boiling. The heat transfer surface was made from a copper printed circuit board. The size of the heat transfer surface was 10 mm × 10 mm. Direct current was supplied to the heat transfer surface to heat it up. The Bakelite plate of the backside of the copper layer was taken off at the center portion of the heat transfer surface. The test vessel was a closed 200-mm cube container made of duralumin. It has transparent view windows on opposing side walls made of a Polycarbonate plate to observe a boiling state. Heat transfer surface was placed at the bottom of the test vessel. Distilled water was used for the experiments. The instantaneous variation of the backside temperature of the heat transfer surface was measured with an infrared radiation camera. Bubble behavior was recorded with a high speed video camera. The time and the space resolution of the infrared radiation cameras used in present experiments were 60 Hz and 0.1 mm × 0.1 mm, and 120 Hz and 0.315 mm × 0.315 mm, respectively. When the heat flux was increased, the instantaneous surface temperature variation explain the pattern. In the isolated bubble region, surface temperature was uniform during waiting time. When boiling bubble generation started, a large dip in the surface temperature was formed under the bubble. After the bubble left from the heat transfer surface, the surface temperature returned to former uniform temperature distribution. Surface temperature was not affected by the bubble generation beyond 1.8 mm from the center of the bubble. In the intermediate and high heat flux region, the variation of surface temperature and heat flux were small. Rather the heat flux variation range was close to that at the isolated boiling region.

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.

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.

Study of Surface Temperature Distribution in Plastic Sheet Spraying

2010 ◽  
Vol 43 ◽  
pp. 703-706
Author(s):  
Zai Liang Chen ◽  
Ji Zhong Yan
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Surface Temperature ◽  
Ansys Software ◽  
Plastic Sheet ◽  
Surface Temperature Distribution ◽  
Heat Transfer Theory ◽  
The Right ◽  
Surface Temperature Field

The heater’s setting temperature is calculated by using the heat transfer theory. Using the thermal module of ANSYS software to simulate the plastic sheet’s surface temperature field, acquired the distribution of the plastic sheet’s surface temperature field. The results show to get even spraying with the right temperature for spraying experiments.

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