Digital Holography for Local Heat Flux Measurement along the Surface of Heated Wire

2019 ◽  
Author(s):  
Varun Kumar ◽  
Chandra Shakher
Keyword(s):  
Heat Flux ◽  
Digital Holography ◽  
Flux Measurement ◽  
Local Heat ◽  
Heat Flux Measurement ◽  
Heated Wire ◽  
Local Heat Flux

Local Heat Flux Measurement in a Permanent Magnet Motor at No Load

2013 ◽  
Vol 60 (11) ◽  
pp. 4852-4860 ◽  
Author(s):  
Hanne K. Jussila ◽  
Andrey V. Mityakov ◽  
Sergey Z. Sapozhnikov ◽  
Vladimir Y. Mityakov ◽  
Juha Pyrhonen
Keyword(s):  
Heat Flux ◽  
Permanent Magnet ◽  
Flux Measurement ◽  
Local Heat ◽  
Permanent Magnet Motor ◽  
Heat Flux Measurement ◽  
Local Heat Flux

scholarly journals New technique of the local heat flux measurement in combustion chambers of steam boilers

2011 ◽  
Vol 32 (3) ◽  
pp. 103-116 ◽  
Author(s):  
Jan Taler ◽  
Dawid Taler ◽  
Tomasz Sobota ◽  
Piotr Dzierwa
Keyword(s):  
Heat Flux ◽  
Flux Measurement ◽  
Local Heat ◽  
New Technique ◽  
Combustion Chambers ◽  
Heat Flux Measurement ◽  
Water Wall ◽  
Steam Boilers ◽  
Local Heat Flux ◽  
Heat Flux Meter

New technique of the local heat flux measurement in combustion chambers of steam boilers A new method for measurement of local heat flux to water-walls of steam boilers was developed. A flux meter tube was made from an eccentric tube of short length to which two longitudinal fins were attached. These two fins prevent the boiler setting from heating by a thermal radiation from the combustion chamber. The fins are not welded to the adjacent water-wall tubes, so that the temperature distribution in the heat flux meter is not influenced by neighbouring water-wall tubes. The thickness of the heat flux tube wall is larger on the fireside to obtain a greater distance between the thermocouples located inside the wall which increases the accuracy of heat flux determination. Based on the temperature measurements at selected points inside the heat flux meter, the heat flux absorbed by the water-wall, heat transfer coefficient on the inner tube surface and temperature of the water-steam mixture was determined.

Design and Calibration of a Local Heat-Flux Measurement System for Unsteady Flows

1989 ◽  
Vol 111 (2) ◽  
pp. 552-557 ◽  
Author(s):  
D. S. Campbell ◽  
M. Gundappa ◽  
T. E. Diller
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Heat Flux ◽  
Measurement System ◽  
Radiant Energy ◽  
Unsteady Flows ◽  
Flux Measurement ◽  
Local Heat ◽  
Heat Flux Measurement ◽  
Local Heat Flux

A local heat–flux measurement system was built, calibrated, and tested for use in unsteady flows. The system was designed to maintain constant-wall-temperature boundary conditions. The measuring element is a thin-film heat flux gage made by sputter-coating gold onto a substrate. A constant-temperature anemometer is used to maintain the thin-film gage at a specified temperature under fluctuating conditions. A separate temperature control system maintains the surrounding boundary at the gage temperature. The system was calibrated for both steady and unsteady flows using a specially designed calibrator for local heat flux gages. The steady calibration was done with predominantly convective heat transfer. The unsteady calibration was achieved by adding oscillating radiant energy to the surface. Consequently, quantitative results can be obtained for both the mean and fluctuating components of the heat transfer. The frequency response was good to over 90 Hz. Sample results are presented of the unsteady heat transfer over a circular cylinder caused by natural vortex shedding at 70 to 80 Hz.

scholarly journals Gradient heat flux measurement during condensation at the surfaces of pipes

2019 ◽  
Vol 140 ◽  
pp. 06006
Author(s):  
Sergey Sapozhnikov ◽  
Vladimir Mityakov ◽  
Alexander Babich ◽  
Elza Zainullina
Keyword(s):  
Heat Flux ◽  
Local Heat Transfer ◽  
Flux Measurement ◽  
Local Heat ◽  
Steam Condensation ◽  
Transfer Coefficients ◽  
Pipe Length ◽  
Heat Transfer Coefficients ◽  
Heat Flux Measurement ◽  
New Information

Gradient heat flux measurement was used to study steam condensation at the inner and outer surfaces of pipes. Experimental setups were developed, manufactured and tested. The setups were able to incline the pipes for different angles relative to vertical and to rotate them around their main axes. Local heat transfer coefficients (HTC) along the pipe length and perimeter were determined. Formation and motion of condensate film were studied. The results are corresponding to classical ideas and give us some new information.

Numerical analysis of local heat flux and thin-slab solidification in a CSP funnel-type mold with electromagnetic braking

2020 ◽  
Vol 117 (6) ◽  
pp. 602
Author(s):  
Heping Liu ◽  
Jianjun Zhang ◽  
Hongbiao Tao ◽  
Hui Zhang
Keyword(s):  
Heat Flux ◽  
Casting Speed ◽  
Shell Growth ◽  
Local Heat ◽  
Operating Conditions ◽  
Thin Slab ◽  
Wide Face ◽  
Slab Width ◽  
Steel Grades ◽  
Local Heat Flux

In this article, based on the actual monitored temperature data from mold copper plate with a dense thermocouple layout and the measured magnetic flux density values in a CSP thin-slab mold, the local heat flux and thin-slab solidification features in the funnel-type mold with electromagnetic braking are analyzed. The differences of local heat flux, fluid flow and solidified shell growth features between two steel grades of Q235B with carbon content of 0.19%C and DC01 of 0.03%C under varying operation conditions are discussed. The results show the maximum transverse local heat flux is near the meniscus region of over 0.3 m away from the center of the wide face, which corresponds to the upper flow circulation and the large turbulent kinetic energy in a CSP funnel-type mold. The increased slab width and low casting speed can reduce the fluctuation of the transverse local heat flux near the meniscus. There is a decreased transverse local heat flux in the center of the wide face after the solidified shell is pulled through the transition zone from the funnel-curve to the parallel-cure zone. In order to achieve similar metallurgical effects, the braking strength should increase with the increase of casting speed and slab width. Using the strong EMBr field in a lower casting speed might reverse the desired effects. There exist some differences of solidified shell thinning features for different steel grades in the range of the funnel opening region under the measured operating conditions, which may affect the optimization of the casting process in a CSP caster.

Sign in / Sign up

Export Citation Format

Share Document