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<article language="en">
	<journal>
		<journal_title>Hydrology and Earth System Sciences</journal_title>
		<journal_url>www.hydrol-earth-syst-sci.net</journal_url>
		<issn>1027-5606</issn>
		<eissn>1607-7938</eissn>
		<volume_number>11</volume_number>
		<issue_number>2</issue_number>
		<publication_year>2007</publication_year>
	</journal>
	<doi>10.5194/hess-11-753-2007</doi>
	<article_url>http://www.hydrol-earth-syst-sci.net/11/753/2007/</article_url>
	<abstract_html>http://www.hydrol-earth-syst-sci.net/11/753/2007/hess-11-753-2007.html</abstract_html>
	<fulltext_pdf>http://www.hydrol-earth-syst-sci.net/11/753/2007/hess-11-753-2007.pdf</fulltext_pdf>
	<start_page>753</start_page>
	<end_page>768</end_page>
	<publication_date>2007-01-17</publication_date>
	<article_title content_type="html">Constructal theory of pattern formation</article_title>
	<authors>
		<author numeration="1" affiliations="1">
			<name>A. Bejan</name>
			<email>abejan@duke.edu</email>
		</author>
	</authors>
	<affiliations>
		<affiliation numeration="1" content_type="html">Duke University, Durham, North Carolina, USA</affiliation>
	</affiliations>
	<abstract content_type="html">This review article shows that the occurrence of macroscopic flow
configuration is a universal natural phenomenon that can be explained and
predicted on the basis of a principle of physics (the constructal law):
&quot;For a flow system to persist in time (to survive) it must evolve in such a
way that it provides easier and easier access to the currents that flow
through it&quot;. The examples given in this article come from natural inanimate
flow systems with configuration: duct cross-sections, open channel
cross-sections, tree-shaped flow architectures, and turbulent flow structure
(e.g., eddies, laminar lengths before transition). Other examples that are
treated in the literature, and which support the constructal law, are the
wedge-shape of turbulent shear layers, jets and plumes, the frequency of
vortex shedding, Bénard convection in fluids and fluid-saturated porous
media, dendritic solidification, the coalescence of solid parcels suspended
in a flow, global atmospheric and oceanic circulation and climate, and
virtually all architectural features of animal design. The constructal law
stresses the importance of reserving a place for pure theory in research,
and for constantly searching for new physics &amp;ndash; new summarizing principles that
are general, hence useful.</abstract>
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</article>

