scholarly journals Two-dimensional transient temperature distribution measurement of GaN Light-emitting diode using high speed camera

2021 ◽  
pp. 1-1
Author(s):  
Guangheng Xiao ◽  
Wujun Du ◽  
Zhiyun Wang ◽  
Guolong Chen ◽  
Lihong Zhu ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
High Speed ◽  
Light Emitting Diode ◽  
Transient Temperature ◽  
High Speed Camera ◽  
Two Dimensional ◽  
Distribution Measurement ◽  
Light Emitting ◽  
Transient Temperature Distribution ◽  
Temperature Distribution Measurement

Development of a High-Pressure, High-Temperature, Optically Accessible Continuous-Flow Vessel for Fuel-Injection Experiments

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Kemar C. James ◽  
Jin Wang ◽  
Michael C. Maynard ◽  
Zackery B. Morris ◽  
Brian T. Fisher
Keyword(s):  
High Pressure ◽  
Continuous Flow ◽  
High Speed ◽  
Fuel Injection ◽  
Light Emitting Diode ◽  
Cone Angle ◽  
High Speed Camera ◽  
Light Emitting ◽  
High Pressure High Temperature ◽  
Spray Visualization

A vessel has been designed for nonreacting fuel-injection experiments with continuous flow of sweep gas at pressures up to 1380 kPa and temperatures up to 200 °C. Four orthogonal windows provide optical access for high-speed spray-visualization using a fast-pulsed light emitting diode (LED) and a high-speed camera. Initial experiments have been conducted to determine spray characteristics of n-heptane. At room conditions, liquid length and cone angle were 170 mm and 14.5 deg, respectively. With air flow in the chamber at 690 kPa and 100 °C, liquid length was considerably shorter at 92 mm and cone angle was wider at 16.5 deg.

Investigation of Temperature Distribution in the Workpiece During High Speed Deep Surface Grinding using FEM

2012 ◽  
Vol 2 (3) ◽  
pp. 16-33
Author(s):  
Audhesh Narayan ◽  
Vinod Yadava
Keyword(s):  
Temperature Distribution ◽  
High Speed ◽  
Element Model ◽  
Surface Grinding ◽  
Depth Of Cut ◽  
Transient Temperature ◽  
Deep Surface ◽  
Transient Temperature Distribution ◽  
Flux Profile ◽  
Wheel Material

High amount of energy generated in the grinding zone is dissipated as a heat which leads to thermal damage to the workpiece. Heat transfer phenomena in high speed deep surface grinding (HSDSG) is entirely different than conventional shallow cut grinding. Due to high wheel speed and large depth of cut, the temperature rise in the grinding zone becomes very high during high speed deep surface grinding. Therefore, investigation of the temperature distribution becomes important in such situations. In this paper, a two dimensional thermal based finite element model has been developed to investigate the transient temperature distribution within the contact zone as well as in the whole workpiece due to high speed deep surface grinding. After comparing the results of present model with the available results, the model is used to study the effect of different input parameters such as depth of cut, workpiece speed, heat flux profile and wheel material on transient temperature distribution.

A Monochrome Light-Emitting Diode Moiré Deflectometry Technique for Two-Dimensional Temperature Measurement

2014 ◽  
Vol 136 (10) ◽  
Author(s):  
Jing-Nang Lee ◽  
Chien-Chih Chen
Keyword(s):  
Temperature Distribution ◽  
Free Boundary ◽  
Temperature Measurement ◽  
Light Emitting Diode ◽  
Vertical Wall ◽  
Laser Printer ◽  
Measured Temperature ◽  
Two Dimensional ◽  
Light Emitting ◽  
Moiré Deflectometry

This article develops low cost moiré deflectometry for two-dimensional temperature measurement in free boundary environment. Experimental setup uses a red monochrome light-emitting diode (LED) lamp with wavelength range of 625–635 nm as light source. In process, the light first runs through the convex lens and then propagates to the parabolic mirror with diameter of 406 mm and f/4.5 for generating the parallel light. The parallel light further propagates to test object and through two gratings both with pitch of 254 lpi which are printed by laser printer. Behind the two gratings, a CCD camera is applied to capture the image, the distorted fringes. Based on the moiré deflectometry theory, the two-dimensional temperature distribution in free boundary environment can be determined in terms of the captured fringe shift analysis. This work has successfully measured the two-dimensional temperature distribution in free boundary environment with heat source models of 40–95 °C vertical wall, 60 W light bulb, and burning candle flame. The measured temperature deviations between moiré deflectometry and thermocouple thermometer are all less than 5%.

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