Investigative Study of Local Sherwood Numbers Using Phase Measurement Interferometry

2004 ◽  
Author(s):  
David McGuire ◽  
Tara M. Dalton ◽  
Mark R. Davies
Keyword(s):  
Mass Transfer ◽  
Flat Plate ◽  
Concentration Profile ◽  
Phase Measurement ◽  
Speckle Pattern ◽  
Momentum Transport ◽  
Electronic Speckle Pattern Interferometry ◽  
Optical Technique ◽  
Mass Transfer Equation ◽  
The Relationship

This paper investigates the relationship between mass and momentum transport. This study of mass transfer is an important design consideration when looking at engineering processes such as evaporation, chemical reactions, corrosion and mixing. Little is know about the relationship. Using the non-intrusive optical technique of Electronic Speckle Pattern Interferometry (ESPI), concentration profile measurements were carried out. A phase-shifting algorithm was also employed to give whole field measurements. Momentum transport in the velocity boundary layer was examined using Particle Image Velocimetry (PIV), which is also a non-intrusive optical technique. The two measurements were taken independently so as to reduce the effect that seed particles may have on the interferometric measurements. A concentration profile was developed above a surface by passing airflow across a flat plate containing a well of ethanol. The rate of mass transfer is obtained from the concentration profile produced as the ethanol vapour diffuses into the airflow. The experiment is set up to measure diffusion from a flat plate and to compare it with the integral solution of the mass transfer equation. Data is presented to show the dependence of the Sherwood number on the Reynolds number.

Experimental Study of Local Mass Transfer From a Flat Plate in Uniform Flow Using Electronic Speckle Pattern Interferometry

Volume 1 ◽  
2004 ◽  
Author(s):  
Tara M. Dalton ◽  
David McGuire ◽  
Mark R. Davies
Keyword(s):  
Mass Transfer ◽  
Reynolds Number ◽  
Flat Plate ◽  
Concentration Profile ◽  
Speckle Pattern ◽  
Mass Transfer Rate ◽  
Leading Edge ◽  
Field Measurements ◽  
Electronic Speckle Pattern Interferometry ◽  
Novel Approach

In this paper an investigative study of the relationship between mass and momentum transport, which have a mutual dependence, is presented. Mass transfer is an important design consideration in engineering processes such as evaporation, chemical reactions, corrosion and mixing. The effect that Reynolds number and distance from the leading edge has on mass transport from fluid to fluid interface on flat plate geometry is examined. A concentration profile is developed above a surface by passing airflow across the plate containing a well of ethanol. The rate of mass transfer is obtained from the concentration profile produced as the ethanol vapour diffuses in the airflow. Measurements are taken using the non-intrusive optical technique of Electronic Speckle Pattern Interferometry (ESPI), which has not been applied in this manner before. This novel approach offers the ability to measure in real time the mass transfer rate. A phase-shifting algorithm is also employed to give whole field measurements. The experimental results compare well to the theoretical prediction, showing that as expected the Sherwood number increases with increasing Reynolds number.

Robust phase unwrapping algorithm based on Zernike polynomial fitting and Swin-Transformer network

2022 ◽  
Author(s):  
Zixin Zhao ◽  
Menghang Zhou ◽  
Yijun Du ◽  
Junxiang Li ◽  
Chen Fan ◽  
...  
Keyword(s):  
Speckle Pattern ◽  
Phase Unwrapping ◽  
Electronic Speckle Pattern Interferometry ◽  
Polynomial Fitting ◽  
Regression Problem ◽  
Phase Measurements ◽  
Zernike Polynomial ◽  
Polynomial Coefficients ◽  
Open Issue ◽  
The Relationship

Abstract Phase unwrapping plays an important role in optical phase measurements. In particular, phase unwrapping under heavy noise conditions remains an open issue. In this paper, a deep learning-based method is proposed to conduct the phase unwrapping task by combining Zernike polynomial fitting and a Swin-Transformer network. In this proposed method, phase unwrapping is regarded as a regression problem, and the Swin-Transformer network is used to map the relationship between the wrapped phase data and the Zernike polynomial coefficients. Because of the self-attention mechanism of the transformer network, the fitting coefficients can be estimated accurately even under extremely harsh noise conditions. Simulation and experimental results are presented to demonstrate the outperformance of the proposed method over the other two polynomial fitting-based methods. This is a promising phase unwrapping method in optical metrology, especially in electronic speckle pattern interferometry.

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