Koeficient upora: Razlika med redakcijama

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Pri drugih telesih, kot so npr. majhni delci, koeficient upora ni konstanten in je funkcija Reynoldsovega števila.<ref>Clift, Grace, Weber (1978)</ref><ref>Briens (1991).</ref><ref>Haider, Levenspiel (1989).</ref> Pri majhnem Reynoldsovem številu tok okrog telesa ne preide v turbulentnega in ostaja laminaren, tudi, ko se loči od površine telesa. Pri zelo malih Reynoldsovih številih brez ločitve toka je sila upora sorazmerna s hitrstjo <math>v</math> in ne z njenim kvadratom <math>v^{2}</math>. Za [[krogla|kroglo]] v tem primeru velja [[Stokesov zakon]]. Reynoldosvo število bo majhno za majhna telesa, majhne hitrosti in zelo viskozne tekočine.<ref name="Clancy_4.17"/>
 
==Primeri==
{| class="wikitable sortable" style="font-size:98%; width:400px;"
|+[http://web.archive.org/web/20070715171817/http://aerodyn.org/Drag/tables.html Shapes]<!-- [http://aerodyn.org/Drag/tables.html] (link broken, archived page: -->
! ''c''<sub>d</sub>
! class="unsortable"| Primer
|-
| 0.001 || plošča vzporedno z tokom (laminarni)(<math>\!\ Re < 10^5</math>)
|-
| 0.005 || plošča vzporedno z tokom (turbulentni) (<math>\!\ Re > 10^5</math>)
|-
| 0.075 || [[Pac-car]]
|-
| 0.1 || gladka krogla (<math>\!\ Re = 10^6</math>)
|-
| 0.15 || Schlörwagen 1939 <ref>{{cite web|url=http://www.nast-sonderfahrzeuge.de/MB-Exotenforum/forum_entry.php?id=25942 |title=MB-Exotenforum |accessdate=2012-01-07}}</ref>
|-
| 0.186-0.189 || [[Volkswagen XL1]] 2014
|-
| 0.19 || [[General Motors EV1]] 1996<ref>[http://www.motortrend.com/auto_news/112_9606_general_motors_ev1/viewall.html MotorTrend: General Motors EV1 - Driving impression], June 1996</ref>
|-
| 0.25 || [[Toyota Prius (XW30)|Toyota Prius]] (3. generacija)
|-
| 0.26 || [[BMW i8]]
|-
| 0.28 || [[Mercedes-Benz CLA-Class]] Type C 117.<ref>{{cite web|url=http://www.mbusa.com/mercedes/vehicles/model/class-CLA/model-CLA250C#!layout=/vehicles/model/specs&class=CLA&model=CLA250C&waypoint=model-specs}}</ref>
|-
| 0.295 || naboj, pri podzvočni hitrosti
|-
| 0.3 ||[[Audi 100]] C3 (1982)
|-
| 0.48 || groba krogla (<math>\!\ Re = \!\ 10^6</math>),<br>[[Volkswagen Beetle]]<ref>{{cite web|url=http://www.maggiolinoweb.it/technique.html |title=Technique of the VW Beetle |publisher=Maggiolinoweb.it |date= |accessdate=2009-10-24}}</ref><ref>{{cite web|url=http://www.mayfco.com/dragcd~1.htm |title=The Mayfield Homepage - Coefficient of Drag for Selected Vehicles |publisher=Mayfco.com |date= |accessdate=2009-10-24}}</ref>
|-
| 0.75 ||modelna raketa<ref>{{cite web|url=http://exploration.grc.nasa.gov/education/rocket/termvr.html |title=Terminal Velocity |publisher=Goddard Space Center |date= |accessdate=2012-02-16}}</ref>
|-
| 1.0 || bicikel z kolesarjem<ref>Wilson, David Gordon (2004): ''Bicycling Science, 3rd ed.''. p. 197, Massachusetts Institute of Technology, Cambridge, ISBN 0-262-23237-5</ref>
|-
| 1.0–1.1 || smučar
|-
| 1.0–1.3 || žice in kabli
|-
| 1.0–1.3 || človek (stoje)
|-
| 1.1-1.3 || smučarski skakalec<ref name=tool>{{cite web|url=http://www.engineeringtoolbox.com/drag-coefficient-d_627.html |title=Drag Coefficient |publisher=Engineeringtoolbox.com |date= |accessdate=2010-12-07}}</ref>
|-
| 1.28 || plošča pravokotno na tok (3D)<ref>{{cite web|url=http://www.grc.nasa.gov/WWW/k-12/airplane/shaped.html | title=Shape Effects on Drag | publisher=NASA | accessdate=2013-03-11}}</ref>
|-
| 1.3–1.5 || [[Empire State Building]]
|-
| 1.8–2.0 || [[Eiffelov stolp]]
|-
| 1.98–2.05 || plošča pravokotno na tok (2D)
|}
 
== Opombe in sklici ==
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