https://www.cfd-online.com/W/index.php?title=Special:Contributions/Bj%C3%B6rn&feed=atom&limit=50&target=Bj%C3%B6rn&year=&month=CFD-Wiki - User contributions [en]2024-03-29T08:46:23ZFrom CFD-WikiMediaWiki 1.16.5https://www.cfd-online.com/Wiki/Law_of_the_wallLaw of the wall2010-06-18T13:53:25Z<p>Björn: </p>
<hr />
<div>In the log layer the velocity profile can be estimated with the log law:<br />
<br />
:<math>u^+ = \frac{1}{\kappa} \, ln(y^+) + B</math><br />
<br />
and close to the wall in the viscous sublayer<br />
<br />
:<math>u^+ = y^+</math><br />
<br />
Where:<br />
<br />
:{| border="1" cellspacing="0" cellpadding="5"<br />
|- <br />
|<math>u^+</math> || [[Dimensionless velocity]]<br />
|-<br />
|<math>y^+</math> || [[Dimensionless wall distance]]<br />
|-<br />
|<math>\kappa</math> || von Karman's constant (<math>\approx 0.41</math>)<br />
|-<br />
|<math>C</math> || Constant (<math>\approx 5.1</math>)<br />
|}<br />
<br />
<br />
''We should have a lin-log plot here of a typical turbulent boundary layer to illustrate where the log-law is valid, anyone have one handy?''<br />
<br />
In the image y is replaced with the letter n. <br />
<br />
[[Image:law of the wall.jpg]]<br />
<br />
{{stub}}</div>Björnhttps://www.cfd-online.com/Wiki/Law_of_the_wallLaw of the wall2010-06-18T13:26:12Z<p>Björn: </p>
<hr />
<div>In the log layer the velocity profile can be estimated with the log law:<br />
<br />
:<math>u^+ = \frac{1}{\kappa} \, ln(y^+) + B</math><br />
<br />
Where:<br />
<br />
:{| border="1" cellspacing="0" cellpadding="5"<br />
|- <br />
|<math>u^+</math> || [[Dimensionless velocity]]<br />
|-<br />
|<math>y^+</math> || [[Dimensionless wall distance]]<br />
|-<br />
|<math>\kappa</math> || von Karman's constant (<math>\approx 0.41</math>)<br />
|-<br />
|<math>C</math> || Constant (<math>\approx 5.1</math>)<br />
|}<br />
<br />
<br />
''We should have a lin-log plot here of a typical turbulent boundary layer to illustrate where the log-law is valid, anyone have one handy?''<br />
<br />
In the image y is replaced with the letter n. <br />
<br />
[[Image:law of the wall.jpg]]<br />
<br />
{{stub}}</div>Björnhttps://www.cfd-online.com/Wiki/File:Law_of_the_wall.jpgFile:Law of the wall.jpg2010-06-18T13:23:01Z<p>Björn: </p>
<hr />
<div></div>Björnhttps://www.cfd-online.com/Wiki/Law_of_the_wallLaw of the wall2010-06-18T13:22:16Z<p>Björn: </p>
<hr />
<div>In the log layer the velocity profile can be estimated with the log law:<br />
<br />
:<math>u^+ = \frac{1}{\kappa} \, ln(y^+) + B</math><br />
<br />
Where:<br />
<br />
:{| border="1" cellspacing="0" cellpadding="5"<br />
|- <br />
|<math>u^+</math> || [[Dimensionless velocity]]<br />
|-<br />
|<math>y^+</math> || [[Dimensionless wall distance]]<br />
|-<br />
|<math>\kappa</math> || von Karman's constant (<math>\approx 0.41</math>)<br />
|-<br />
|<math>C</math> || Constant (<math>\approx 5.1</math>)<br />
|}<br />
<br />
<br />
''We should have a lin-log plot here of a typical turbulent boundary layer to illustrate where the log-law is valid, anyone have one handy?''<br />
<br />
[[Image:law of the wall.jpg]]<br />
<br />
{{stub}}</div>Björnhttps://www.cfd-online.com/Wiki/File:Law_of_the_wall.JPGFile:Law of the wall.JPG2010-06-18T13:18:54Z<p>Björn: </p>
<hr />
<div></div>Björn