Stability of the non-wetting state in a droplet impinging on surfaces with multiple holes

2021 ◽  
Vol 33 (12) ◽  
pp. 123315
Author(s):  
Zhicheng Yuan ◽  
Mitsuhiro Matsumoto ◽  
Ryoichi Kurose
Keyword(s):  
Author(s):  
Edward D. DeLamater ◽  
Walter R. Courtenay ◽  
Cecil Whitaker

Comparative scanning electron microscopy studies of fish scales of different orders, families, genera and species within genera have demonstrated differences which warrant elaboration. These differences in detail appear to be sufficient to act as “fingerprints”, at least, for family differences. To date, the lateral line scales have been primarily studied. These demonstrate differences in the lateral line canals; the pattern of ridging with or without secondary protuberances along the edges; the pattern of spines or their absence on the anterior border of the scales; the presence or absence of single or multiple holes on the ventral and dorsal sides of the lateral line canal covers. The distances between the ridges in the pattern appear likewise to be important.A statement of fish scale structure and a comparison of family and species differences will be presented.The authors wish to thank Dr. Donald Marzalek and Mr. Wallace Charm of the Marine and Atmospheric Laboratory of the University of Miami and Dr. Sheldon Moll and Dr. Richard Turnage of AMR for their exhaustive help in these preliminary studies.


2013 ◽  
Vol 3 (1) ◽  
pp. 30-36
Author(s):  
Neeraj Sharma ◽  
◽  
Rahul Dev Gupta ◽  
Nirmal Kumar ◽  
◽  
...  

Author(s):  
Ghazi H. Asmar ◽  
Elie A. Chakar ◽  
Toni G. Jabbour

The Schwarz alternating method, along with Muskhelishvili’s complex potential method, is used to calculate the stresses around non-intersecting circular holes in an infinite isotropic plate subjected to in-plane loads at infinity. The holes may have any size and may be disposed in any manner in the plate, and the loading may be in any direction. Complex Fourier series, whose coefficients are calculated using numerical integration, are incorporated within a Mathematica program for the determination of the tangential stress around any of the holes. The stress values obtained are then compared to published results in the literature and to results obtained using the finite element method. It is found that part of the results generated by the authors do not agree with some of the published ones, specifically, those pertaining to the locations and magnitudes of certain maximum stresses occurring around the contour of holes in a plate containing two holes at close proximity to each other. This is despite the fact that the results from the present authors’ procedure have been verified several times by finite element calculations. The object of this paper is to present and discuss the results calculated using the authors’ method and to underline the discrepancy mentioned above.


Author(s):  
Keita Yunoki ◽  
Tomoya Murota ◽  
Keisuke Miura ◽  
Teruyuki Okazaki

We have developed a burner for the gas turbine combustor, which was high efficiency and low environmental load. This burner is named the “coaxial jet cluster burner” and, as the name indicates, it has multiple fuel nozzles and holes in a coaxial arrangement. To form lean premixed combustion, this burner mixes fuel and air in the multiple holes rapidly. The burner can change the combustion form between premixed and non-premixed combustion by controlling the mixing. However, the combustion field coexisting with premixed and non-premixed combustion is complicated. The phenomena that occur in the combustion field should be understood in detail. Therefore, we have developed the hybrid turbulent combustion (HTC) model to calculate the form in which non-premixed flame coexists with premixed flame. Turbulent flow has been simulated using a large eddy simulation (LES) with a dynamic sub grid scale (SGS) model coupled with the HTC model. These models were programmed to a simulation tool based on the OpenFOAM library. However, there were unclear points about their applicability to an actual machine evaluation and the predictive precision of CO concentration which affects burner performance. In this study, we validate the HTC model by comparing its results with measured gas temperature and gas concentration distributions obtained with a coaxial jet cluster burner test rig under atmospheric pressure. In addition, we analyze the CO generation mechanism for the lean premixed combustion in the burner.


2016 ◽  
Vol 710 ◽  
pp. 357-362
Author(s):  
Irene Scheperboer ◽  
Evangelos Efthymiou ◽  
Johan Maljaars

Aluminium plates containing a single hole or multiple holes in a row are recently becoming very popular among architects and consultant engineers in many constructional applications, due to their reduced weight, as well as facilitating ventilation and light penetration of the buildings. However, there are still uncertainties concerning their structural behaviour, preventing them from wider utilization. In the present paper, local buckling phenomenon of perforated aluminium plates has been studied using the finite element method. For the purposes of the research work, plates with simply supported edges in the out-of-plane direction and subjected to uniaxial compression are examined. In view of perforations, circular cut-outs and the total cut-out size has been varied between 5 and 40% of the total plate area. Moreover, different perforation patterns have been investigated, from a single, central cut-out to a more refined pattern consisting of up to 25 holes equally distributed over the plate. Regarding the material characteristics, several aluminium alloys are considered and compared to steel grade A36 on plates of different slenderness. For each case the critical (Euler) buckling load and the ultimate resistance has been determined.A study into the boundary conditions of the plate showed that the restrictions at the edges parallel to the load direction have a large influence on the critical buckling load. Restraining the top or bottom edge does not significantly influence the resistance of the plate.The results showed that the ultimate resistance of aluminium plates containing multiple holes occurs at considerably larger out-of-plane displacement as that of full plates. For very large total cut-out, a plate containing a central hole has a larger resistance than a plate with equal cut-out percentage but with multiple holes. The strength and deformation in the post-critical regime, i.e. the difference between the critical buckling load and the ultimate resistance, differs significantly for different number of holes and cut-out percentage.


2018 ◽  
Vol 144 (9) ◽  
pp. 04018147 ◽  
Author(s):  
Zhixiang Li ◽  
Canhui Zhao ◽  
Kailai Deng ◽  
Weian Wang

2010 ◽  
Vol 118-120 ◽  
pp. 269-273
Author(s):  
Jin Fang Zhao ◽  
Li Yang Xie ◽  
Jian Zhong Liu ◽  
Qun Zhao

Multiple site damage (MSD) is the occurrence of small fatigue cracks at several sites within aging aircraft structures. Focusing on this typical structure, an analytical method for calculating the stress intensity factor (SIF) of an infinite plate containing multiple holes was introduced in this paper. The properties of complex variable functions are used to evaluate the stress function. The approximate superposition method is applied to solve SIF problems on multiple holes. Some numerical examples of radial cracks appearing at the boundary of two circular holes are examined by this method. By comparing the analytical and finite analysis results it was realized that the analytical results are accurate and reliable. This modified analytical method is easier to apply than traditional analytical method and can provide SIF solutions for an infinite plate containing multiple holes.


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