Analysis of the Visualization Region in Near-Wall Fluid Layer by High-Speed Infrared Thermography

2020 ◽  
Vol 75 (2) ◽  
pp. 143-147
Author(s):  
A. M. Shagiyanova ◽  
E. Yu. Koroteeva ◽  
I. A. Znamenskaya ◽  
M. E. Dashyan ◽  
L. A. Blagonravov ◽  
...  
Keyword(s):  
Infrared Thermography ◽  
High Speed ◽  
Fluid Layer ◽  
Near Wall

Simultaneous Measurements of Unsteady Thermal and Flow Fluctuations Using High-Speed Infrared Thermography and PIV Over a Backward Facing Step

2017 ◽  
Author(s):  
Shunsuke Yamada ◽  
Hajime Nakamura
Keyword(s):  
Heat Transfer ◽  
Infrared Thermography ◽  
Vortex Structure ◽  
High Speed ◽  
Stereoscopic Particle Image Velocimetry ◽  
Heated Wall ◽  
Wall Region ◽  
Backward Facing Step ◽  
Combined System ◽  
Near Wall

In order to investigate the flow and heat transfer fluctuations in the near-wall region downstream a backward facing step, a Time-resolved Stereoscopic Particle Image Velocimetry (TS-PIV) and a high-speed infrared thermography (IRT) combined system was constructed. Using this measurement system, the time series of the velocity in the vicinity of the heated wall and the heat transfer on the heated wall were measured at Reynolds number, which is based on the step height and inlet mainstream velocity, of 2.5 × 103. It confirmed the validity of the velocity fluctuation obtained by using TS-PIV. The results showed that the forward and downwash flows correspond to the enhancement of the heat transfer in the near-wall region. Also, the vortex structure in the yz plane was detected by Qyz-criterion, and the locational relationship between the vortex structure and the heat transfer enhancement was investigated.

Evaluation of Package Defects by Thermal Imaging Techniques

2002 ◽  
Author(s):  
Yongmei Liu ◽  
Rajen Dias
Keyword(s):  
Infrared Thermography ◽  
Thermal Imaging ◽  
High Speed ◽  
Imaging Techniques ◽  
Thermal Response ◽  
Analysis Tool ◽  
Nondestructive Analysis ◽  
Ir Camera ◽  
External Heating

Abstract Study presented here has shown that Infrared thermography has the potential to be a nondestructive analysis tool for evaluating package sublayer defects. Thermal imaging is achieved by applying pulsed external heating to the package surface and monitoring the surface thermal response as a function of time with a high-speed IR camera. Since the thermal response of the surface is affected by the defects such as voids and delamination below the package surface, the technique can be used to assist package defects detection and analysis.

Tensile Fracture Characterization of Thermosetting Plastics by Infrared Thermography Technique

2009 ◽  
Vol 417-418 ◽  
pp. 433-436
Author(s):  
Jeong Guk Kim
Keyword(s):  
Infrared Thermography ◽  
High Speed ◽  
Unsaturated Polyester ◽  
In Situ Monitoring ◽  
Tensile Fracture ◽  
Fracture Characterization ◽  
Ir Camera ◽  
Strain Behavior ◽  
Plastic Materials ◽  
Rail Structure

The tensile fracture behavior of thermosetting plastic materials was investigated with the aid of a nondestructive evaluation (NDE) technique. The materials, unsaturated polyester resin (UPR), which is applicable to buffer the vibration and impact properties in rail structure, were used for this investigation. In order to explain a stress-strain behavior of plastic sample, the infrared thermography technique was applied. A high-speed infrared (IR) camera was employed for in-situ monitoring of progressive damages of UPR samples during tensile testing. In this investigation, the IR thermography technique was used to facilitate a better understanding of damage evolution, fracture mechanism, and failure mode of thermosetting plastic materials during monotonic loadings.

Velocity and Volume Fraction Measurements of Granular Flows in a Steep Flume

2021 ◽  
Author(s):  
Luca Sarno ◽  
Maria Nicolina Papa ◽  
Luigi Carleo ◽  
Paolo Villani
Keyword(s):  
High Speed ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Granular Flows ◽  
Indirect Measurement ◽  
Measuring Instruments ◽  
Second Order Statistics ◽  
Granular Dynamics ◽  
Image Velocimetry ◽  
Near Wall

ABSTRACT Laboratory experiments on granular flows remain essential tools for gaining insight into several aspects of granular dynamics that are inaccessible from field-scale investigations. Here, we report an experimental campaign on steady dry granular flows in a flume with inclination of 35°. Different flow rates are investigated by adjusting an inflow gate, while various kinematic boundary conditions are observed by varying the basal roughness. The flume is instrumented with high-speed cameras and a no-flicker LED lamp to get reliable particle image velocimetry measurements in terms of both time averages and second-order statistics (i.e., granular temperature). The same measuring instruments are also used to obtain concurrent estimations of the solid volume fraction at the sidewall by employing the stochastic-optical method (SOM). This innovative approach uses a measurable quantity, called two-dimensional volume fraction, which is correlated with the near-wall volume fraction and is obtainable from digital images under controlled illumination conditions. The knowledge of this quantity allows the indirect measurement of the near-wall volume fraction thanks to a stochastic transfer function previously obtained from numerical simulations of distributions of randomly dispersed spheres. The combined measurements of velocity and volume fraction allow a better understanding of the flow dynamics and reveal the superposition of different flow regimes along the flow depth, where frictional and collisional mechanisms exhibit varying relative magnitudes.

scholarly journals Non-Destructive Characterization of Railway Materials and Components with Infrared Thermography Technique

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4077 ◽  
Author(s):  
Jeongguk Kim
Keyword(s):  
Infrared Thermography ◽  
Thermal Imaging ◽  
High Speed ◽  
Hot Spot ◽  
Imaging Techniques ◽  
Brake Disc ◽  
Ir Thermography ◽  
Contact Mode ◽  
Non Destructive Evaluation ◽  
Non Destructive

Infrared (IR) thermography technology is one of the leading non-destructive evaluation (NDE) techniques based on infrared detection. Infrared thermography, in particular, has the advantage of not only being used in non-contact mode but also provides full images, real-time inspection, and relatively fast results. These advantages make it possible to perform thermal imaging analysis of railway materials and/or components, such as brake disc simulation, monitoring of abnormal heat generation, and monitoring of temperature changes, during mechanical tests. This study introduces the current state of research on railway materials and/or components using IR thermography technology. An attempt was made to characterize the deterioration of electrical equipment of diesel electric locomotives using infrared thermal imaging techniques. In addition, surface temperature monitoring was performed during tensile testing of railway steels using a high-speed infrared camera. Damage evolution due to the hot spot generation of railway brake discs was successfully monitored using high-speed IR cameras. In this paper, IR thermal imaging technology, used as a non-destructive evaluation analysis in the railway field, was introduced, and the results of recent research are presented.

scholarly journals High speed heterodyne infrared thermography applied to thermal diffusivity identification

2011 ◽  
Vol 82 (5) ◽  
pp. 054901 ◽  
Author(s):  
C. Pradere ◽  
L. Clerjaud ◽  
J. C. Batsale ◽  
S. Dilhaire
Keyword(s):  
Thermal Diffusivity ◽  
Infrared Thermography ◽  
High Speed
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