CHEMICAL, MECHANICAL AND HYDRODYNAMIC PROPERTIES RESEARCH ON COMPOSITE DRAG REDUCTION SURFACE BASED ON BIOLOGICAL SHARKSKIN MORPHOLOGY AND MUCUS NANOLONG CHAIN

2015 ◽  
Vol 15 (05) ◽  
pp. 1550084 ◽  
Author(s):  
YUEHAO LUO ◽  
DEYUAN ZHANG ◽  
YUFEI LIU ◽  
YUANYUE LI ◽  
E. Y. K. NG
Keyword(s):  
Natural Selection ◽  
Drag Reduction ◽  
Water Tunnel ◽  
Reduction Mechanism ◽  
Hydrodynamic Properties ◽  
The World ◽  
Smooth Skin ◽  
Survival Of The Fittest ◽  
Important Significance ◽  
Long Chain

Natural selection, survival of the fittest. Through millions of years' evolution, shark has become one of the fastest swimming animals in the ocean, and it is very well-known for sharkskin effect, especially for "sharkskin swimsuit". Due to its great superior properties in drag reduction, anti-wear, self-cleaning and so on, the investigations on the essential mechanisms and fabricating methods have attracted so much attention from all over the world, and the achievements have been widely put into application in industry, agriculture, transportation, airspace and so on, and so lots of profits have been obtained so far. In this paper, the method of fabricating artificial composite drag reduction surface based on biological sharkskin morphology and mucus nano-long chain is investigated and studied, the chemical, mechanical and hydrodynamic properties are explored from different aspects in depth, in which, the experimental results in water tunnel showed that the drag-reducing efficiency could surpass 20% with the smooth skin as reference, and the drag reduction mechanism is systematically explained and discussed from different aspects, which has important significance to understand the recent research status and expand the applications of sharkskin in the fluid engineering.

Numerical Simulation of Micro Flow Field on Biomimetic Sharkskin Micro-Grooved Surface

2014 ◽  
Vol 884-885 ◽  
pp. 378-381 ◽  
Author(s):  
Yue Hao Luo ◽  
Yu Fei Liu
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Drag Reduction ◽  
Reduction Mechanism ◽  
Urgent Problem ◽  
Grooved Surface ◽  
Micro Flow ◽  
Important Significance

It is well-known that sharkskin surface has the effect of inhibiting the occurrence of turbulence and reducing the wall resistance, however, the drag reduction mechanism has developed into an urgent problem to be resolved now. According to the actual circumstance, for purpose of obtaining the best drag-reducing efficiency, the biomimetic sharkskin micro-grooved surface is designed according to the relevant literatures and research achievements, and numerical simulation of the micro flow field on the biomimetic sharkskin surface is carried out comprehensivley, which has the important significance to explain the drag reduction mechanism.

INFLUENCE OF MORPHOLOGY FOR DRAG REDUCTION EFFECT OF SHARKSKIN SURFACE

2014 ◽  
Vol 14 (02) ◽  
pp. 1450029 ◽  
Author(s):  
YUEHAO LUO ◽  
YUFEI LIU ◽  
DEYUAN ZHANG ◽  
E. Y. K. NG
Keyword(s):  
Natural Selection ◽  
Flow Field ◽  
Drag Reduction ◽  
Hydrophobic Effect ◽  
Academic Research ◽  
Engineering Application ◽  
Reduction Mechanism ◽  
Urgent Problem ◽  
Micro Flow ◽  
Reduction Effect

Through millions of years' natural selection, creature has formed their own unique functional surfaces. Shark is one of the fastest animals in the ocean, which is well known for "sharkskin effect". Sharkskin surface is all covered by tiny and rigid scales with sophisticated morphology, which is one important factor to produce the high drag reducing efficiency. However, the drag reduction mechanism of sharkskin has not been understood thoroughly, which has developed into an urgent problem to be resolved. In this paper, the accurate 3D digital model of sharkskin surface is constructed based on the biological prototype and the micro flow field on the near wall is analyzed comprehensively and deeply. In addition, the drag reduction mechanism is explored from different aspects, especially which, the influences of the variation of attack angles of scales, the super-hydrophobic effect and nanochain of mucus on drag-reducing efficiency are taken into consideration, which has great significance on academic research and engineering application.

Drag Reduction Study about Bird Feather Herringbone Riblets

2013 ◽  
Vol 461 ◽  
pp. 201-205 ◽  
Author(s):  
Hua Wei Chen ◽  
Fu Gang Rao ◽  
De Yuan Zhang ◽  
Xiao Peng Shang
Keyword(s):  
Drag Reduction ◽  
Structural Parameters ◽  
Reduction Rate ◽  
Reduction Mechanism ◽  
Surface Drag ◽  
Flight Feather ◽  
Hollow Shaft ◽  
Smooth Edge ◽  
Bird Feather ◽  
Wild Goose

Flying bird has gradually formed airworthy structures e.g. streamlined shape and hollow shaft of feather to improve flying performance by millions of years natural selection. As typical property of flight feather, herringbone-type riblets can be observed along the shaft of each feather, which caused by perfect alignment of barbs. Why bird feather have such herringbone-type riblets has not been extensively discussed until now. In this paper, microstructures of secondary feathers are investigated through SEM photo of various birds involving adult pigeons, wild goose and magpie. Their structural parameters of herringbone riblets of secondary flight feather are statistically obtained. Based on quantitative analysis of feathers structure, one novel biomimetic herringbone riblets with narrow smooth edge are proposed to reduce surface drag. In comparison with traditional microgroove riblets and other drag reduction structures, the drag reduction rate of the proposed biomimetic herringbone riblets is experimentally clarified up to 15%, much higher than others. Moreover, the drag reduction mechanism of herringbone riblets are also confirmed and exploited by CFD.

scholarly journals Agrowisata Berkelanjutan Berbasis Kopi di Satria Agrowisata Desa Manukaya, Kecamatana Tampak Siring, Kabupaten Gianyar, Bali (Studi Evolusi Pariwisata)

2020 ◽  
Vol 8 (2) ◽  
pp. 262
Author(s):  
Febrytha Nur Azizah ◽  
I Putu Anom
Keyword(s):  
Natural Selection ◽  
Evolutionary Process ◽  
Secondary Data ◽  
Primary Data ◽  
Tourist Attraction ◽  
Theory Of Evolution ◽  
Alternative Tourism ◽  
The World ◽  
Tourism Activity ◽  
Main Attraction

Agro-tourism is an alternative tourism activity that relies on plantations and agriculture as its main attraction. Along with the development of tourism, agro-tourism has now become an economic driving commodity for the surrounding community, so that agro-tourism is increasingly taken into account in the world of tourism. The development of an agro-tourism can not be separated from the evolutionary process that occurs through various stages of the beginning of the tourist attraction built until now. This study aims to determine the evolution of developments in Satria Agrowisata. The research method used is descriptive qualitative by conducting data collection techniques through online interview as primary data, and conducting online observations as secondary data. The results show that Satria Agrowisata can adapt well to the various changes that exist and continue to innovate in order to survive in the world of tourism until now. In Darwin's theory of evolution, he put forward two key words in his theory, natural selection and adaptation. Natural selection as a mechanism for evolutionary change, and adaptations that occur in its development over time.   Keyword: Evolution, Agrotourism, Satria Agrowisata, Bali.

Spencer, Herbert (1820–1903)

2018 ◽  
Author(s):  
Tim S. Gray
Keyword(s):  
New York ◽  
Natural Selection ◽  
Evolutionary Theory ◽  
Industrial Revolution ◽  
Late Nineteenth Century ◽  
Human Society ◽  
Herbert Spencer ◽  
The World ◽  
The Usa ◽  
Late Nineteenth

Herbert Spencer is chiefly remembered for his classical liberalism and his evolutionary theory. His fame was considerable during the mid- to late-nineteenth century, especially in the USA, which he visited in 1882 to be lionized by New York society as the prophetic philosopher of capitalism. In Britain, however, Spencer’s reputation suffered two fatal blows towards the end of his life. First, collectivist legislation was introduced to protect citizens from the ravages of the industrial revolution, and Spencer’s spirited defence of economic laissez-faire became discredited. Second, his evolutionary theory, which was based largely on the Lamarckian principle of the inheritance of organic modifications produced by use and disuse, was superseded by Darwin’s theory of natural selection. Nearly a century after his death, however, there is renewed interest in his ideas, partly because the world has become more sympathetic to market philosophies, and partly because the application of evolutionary principles to human society has become fashionable once more.

Study on Natural Gas Drag Reduction Agent and Mechanism of Gas Pipelines Drag Reduction

2008 ◽  
Author(s):  
Guoping Li ◽  
Zhiheng Zhang ◽  
Bing Liu ◽  
Chunman Li ◽  
Weichun Chang ◽  
...  
Keyword(s):  
Natural Gas ◽  
Drag Reduction ◽  
Reduction Method ◽  
Radial Pulsation ◽  
Gas Pipelines ◽  
Oil Pipelines ◽  
Oil Flow ◽  
Pipeline Wall ◽  
Gas Drag ◽  
Long Chain

On the basis of the study on the principle of oil flow and that on mechanism of drag reduction and transportation promotion of oil pipelines, the article makes a further research on the Mechanism of Drag Reduction in the gas pipelines. It points out that the basic cause for gas pipelines drag reduction is to control effectively the radial pulsation of gas adjacent to pipeline wall. It is considered that the most effective drag reduction method is to reduce the pipeline wall’s roughness degree and pipeline wall’s undercoat and to make gas drag reduction agent adjacent to pipeline wall. The research shows that gas drag reduction agent should be a polymer and compound with polarity and nonpolarity long chain.

Simulation of Blood Perfusion in Tumour Microvasculature

2007 ◽  
Author(s):  
Jie Wu ◽  
Shixiong Xu ◽  
Quan Long ◽  
Michael W. Collins ◽  
Carola S. Koenig ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Solid Tumors ◽  
Solid Tumor ◽  
Treatment Resistance ◽  
Blood Perfusion ◽  
Tumor Vascularity ◽  
The World ◽  
Adaptive Consequences ◽  
Important Significance

Solid tumor has become one of the most serious diseases that threaten mankind’s health and life all over the world. It is well recognized that structural and functional abnormalities of tumor vascularity and the subsequent microenvironment and cellular adaptive consequences creates a great barrier for drug delivery in solid tumors, contributing to treatment resistance. Hence, the investigation of microcirculatory dynamics in solid tumors has important significance for improving the effectiveness of many anticancer therapies.

Frank Bridge and The Land Without Music

Tempo ◽  
1977 ◽  
pp. 7-11
Author(s):  
Hugh Wood
Keyword(s):  
Natural Selection ◽  
The Other ◽  
Musical Evolution ◽  
Survival Of The Fittest

Why the work of one composer survives and another doesn't remains a little mysterious. I myself incline on the whole to a Darwinian view of musical posterity: it is quality that chiefly determines the survival of the fittest, and some process of natural selection upon this criterion that ensures that the best are sorted out in the end. (If one throws in the other bit of evolutionist jargon—adaptation to one's environment—the limits to pursuing this metaphor become obvious). But temperamentally I distrust the endless discovery of Unjustly Neglected Composers. When the writer Mr. X is spoken of as ‘the persuasive advocate for’ composer Mr. Y, the phrase itself suggests the lawyer doing too good a job, and that the client so skilfully defended is in fact guilty—of lack of distinction anyway, if not lack of talent. There are so many Justly Neglected Composers. Every now and then, though, you make a discovery that upsets the comfortable applecart of this non-revisionist view of musical evolution.

A simple argument against design

2010 ◽  
Vol 47 (4) ◽  
pp. 513-520 ◽  
Author(s):  
DAN MOLLER
Keyword(s):  
Natural Selection ◽  
Simple Argument ◽  
Very Old ◽  
The Earth ◽  
The World ◽  
Technical Sense

AbstractThis paper presents a simple argument against life being the product of design. The argument rests on three points. (1) We can conceive of the debate in terms of likelihoods, in the technical sense – how probable the design hypothesis renders our evidence, versus how probable the competing Darwinian hypothesis renders that evidence. (2) God, as traditionally conceived, had many more options by which to bring about life as we observe it than were available to natural selection. That is, the relevant parameters were, in many cases, far more constrained under natural selection. (3) Utterly mundane features of the world, like that the earth is very old, are actually powerful evidence that the world was not designed, since that outcome was optional on the design hypothesis but nearly inevitable on natural selection.

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