Suitability of Multispectral Radiation Thermometry Emissivity Models for Predicting Steel Surface Temperature

2010 ◽  
Vol 24 (3) ◽  
pp. 662-665 ◽  
Author(s):  
Chang-Da Wen ◽  
Chien-Tsai Lu
Keyword(s):  
Surface Temperature ◽  
Steel Surface ◽  
Radiation Thermometry ◽  
Multispectral Radiation Thermometry

Detection method of combustion oscillation characteristics under strong noise background

2020 ◽  
Vol 21 (6) ◽  
pp. 612
Author(s):  
Yunkun Wei ◽  
Tianhong Zhang ◽  
Zhonglin Lin ◽  
Qi Xie ◽  
Yan Zhang
Keyword(s):  
Radiation Thermometry ◽  
Hydroxyl Group ◽  
Interference Signal ◽  
Engine Vibration ◽  
Combustion Technology ◽  
Lean Fuel ◽  
Combustion Oscillation ◽  
Aero Engines ◽  
Temperature Measurement System ◽  
Multispectral Radiation Thermometry

After the lean fuel premixed combustion technology is applied to aero engines, severe combustion oscillations will be cased and led to hidden safety hazards such as engine vibration, further energy waste and other problems. Therefore, it is increasingly important to actively control combustion oscillations. In this paper, a multispectral radiation thermometry (MRT) is used to analyze the hydroxyl group, which is a measurable research object in the combustion chamber of an aero engine, and to fit the functional relationship between the radiation intensity ratio and the temperature in different bands. The theoretical value of the error is <2%. At the same time, in order to solve the problem of weak detection signal and excessive interference signal, an improved frequency domain filtering method based on fast Fourier transform is designed. Besides, the FPGA platform is used to ensure the real-time performance of the temperature measurement system, and simulations and experiments are performed. An oscillating signal with an oscillation frequency of 315 Hz is obtained on the established test platform, and the error is only 1.42%.

scholarly journals Study on the effect of Weber Number to heat transfer of multiple droplets on hot stainless steel surface

2018 ◽  
Vol 154 ◽  
pp. 01114 ◽  
Author(s):  
Aria Riswanda ◽  
Indro Pranoto ◽  
Deendarlianto ◽  
Indarto ◽  
Teguh Wibowo
Keyword(s):  
Stainless Steel ◽  
Surface Temperature ◽  
Weber Number ◽  
Steel Surface ◽  
Cooling System ◽  
Spray Cooling ◽  
Stainless Steel Surface ◽  
Temperature Decrease ◽  
Evaporation Time ◽  
Decrease Rate

Multiple droplets are drops of water that continuously dropped onto a surface. Spray cooling is an application of the use of droplet on a cooling system. Spray cooling is usually used in a cooling system of electronic devices, and material quenching. In this study, correlations between Weber number and surface temperature decrease rate during multiple droplets impingement are investigated and analyzed. Visualization process is used to help determine the evaporation time of droplets impingement by using high speed camera. Induction stove is used to maintain a stainless steel surface temperature at 120°C, 140°C, and 160°C. The Weber number was varied at 15, and 52.5 to simulate low and medium Weber number. The result of this study shows that increase in Weber number does not increase the temperature decrease rate noticeably. Whereas the Weber number decrease the time required for surface temperature to reach its lowest surface temperature. It was also found that for low and medium Weber number, Weber number affect the evaporation time of multiple droplets after impingement.

Electrical Signatures for Chemical Action at the Work Surface in an Oxyfuel Flame

2018 ◽  
Author(s):  
Christopher R. Martin ◽  
Joseph Kinney ◽  
Andrew Matzik ◽  
Jessica Molina
Keyword(s):  
Surface Temperature ◽  
Steel Surface ◽  
Ion Currents ◽  
Chemical Action ◽  
Dc Voltage ◽  
Work Surface

An oxyfuel cutting torch was biased with a positive DC voltage relative to steel and copper work pieces, and ion currents were seen to flow due to ions generated chemically in the flame and at the work surface. A repeatable 150% rise in these currents occurs over steel at a surface temperature around 1050°C. Equally strong intermittent spikes appear over clean and corroded steel samples alike. They are are easily removed by a median value filter, and are believed to be due to small reacting particulates. Tests in which salt was deliberately deposited on the steel surface produces a signal similar in shape, but exaggerated in magnitude to those currents supposed to be from other surface impurities.

The Analysis of Thermoelectric Signals in Metallic Sliding

1989 ◽  
Vol 111 (1) ◽  
pp. 114-120 ◽  
Author(s):  
Jui-Hsieh Shen ◽  
C. M. Ettles ◽  
H. A. Scarton
Keyword(s):  
Power Spectrum ◽  
Surface Temperature ◽  
Surface Topography ◽  
Temperature Rise ◽  
Signal Analysis ◽  
Steel Surface ◽  
Power Spectra ◽  
Average Temperature ◽  
Voltage Signal ◽  
Temperature Signal

The thermoelectric signal from an Alumel pin sliding over a steel surface was recorded and analyzed. The load, speed and surface topography were varied and correlations were attempted of the voltage signal against several parameters. The average temperature of the whole contact was found to agree fairly consistently with the surface temperature rise models of Blok and Archard. Of the available methods of signal analysis, the power spectrum of the voltage signal was found to give the best understanding of the micro-mechanisms of sliding, particularly when compared against the power spectra of profilometer signals. The largest component of the temperature signal was found to be caused by wavelength components equal to the extent of the contact. The correlation distance β* of the test surfaces was much less than the contact extent and contributed negligibly to the voltage signal rise.

Splat Solidification of Tin Droplets

1996 ◽  
Author(s):  
R. Bhola ◽  
S. Chandra
Keyword(s):  
Experimental Study ◽  
Stainless Steel ◽  
Simple Model ◽  
Surface Temperature ◽  
Steel Surface ◽  
Liquid Droplet ◽  
Contact Angles ◽  
Stainless Steel Surface ◽  
Splat Solidification ◽  
The Impact

Abstract An experimental study was done of the impact and solidification of tin droplets falling on a stainless steel surface. The surface temperature was varied from 25°C to 240°C. Measurements were made of droplet diameters and contact angles during droplet spread. At a surface temperature of 240°C there was no solidification, and a simple model of liquid droplet impact successfully predicted the extent of droplet spread. Droplets impacting on surfaces at 25°C and 150°C solidified before spreading was complete.

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