Difference between revisions of "Expansion wave"

From Glossary of Meteorology
imported>Perlwikibot
(Created page with " {{TermHeader}} {{TermSearch}} <div class="termentry"> <div class="term"> == expansion wave == </div> <div class="definition"><div class="short_definition">(<br/>''Also...")
 
imported>Perlwikibot
Line 9: Line 9:
 
   </div>
 
   </div>
  
<div class="definition"><div class="short_definition">(<br/>''Also called'' rarefaction wave.) A [[simple wave]] or progressive [[disturbance]] in the  [[isentropic]] flow of a compressible fluid, such that the [[pressure]] and [[density]] of a fluid [[particle]]  decrease on crossing the wave in the direction of its motion.</div><br/> <div class="paragraph">This may be illustrated, for example, by the withdrawal of a piston from a gas-filled cylinder.  When the gas is initially at rest in the cylinder, an expansion wave may move into the undisturbed  fluid at the [[speed of sound]] as the piston is withdrawn. The expansion wave is a finite-amplitude  disturbance changing shape as it propagates, but it may or may not be accompanied by a [[shock  wave]] front, with the associated discontinuities. <br/>''See'' [[compression wave]].</div><br/> </div>
+
<div class="definition"><div class="short_definition">(''Also called'' rarefaction wave.) A [[simple wave]] or progressive [[disturbance]] in the  [[isentropic]] flow of a compressible fluid, such that the [[pressure]] and [[density]] of a fluid [[particle]]  decrease on crossing the wave in the direction of its motion.</div><br/> <div class="paragraph">This may be illustrated, for example, by the withdrawal of a piston from a gas-filled cylinder.  When the gas is initially at rest in the cylinder, an expansion wave may move into the undisturbed  fluid at the [[speed of sound]] as the piston is withdrawn. The expansion wave is a finite-amplitude  disturbance changing shape as it propagates, but it may or may not be accompanied by a [[shock  wave]] front, with the associated discontinuities. <br/>''See'' [[compression wave]].</div><br/> </div>
 
</div>
 
</div>
  

Revision as of 14:11, 20 February 2012



expansion wave

(Also called rarefaction wave.) A simple wave or progressive disturbance in the isentropic flow of a compressible fluid, such that the pressure and density of a fluid particle decrease on crossing the wave in the direction of its motion.

This may be illustrated, for example, by the withdrawal of a piston from a gas-filled cylinder. When the gas is initially at rest in the cylinder, an expansion wave may move into the undisturbed fluid at the speed of sound as the piston is withdrawn. The expansion wave is a finite-amplitude disturbance changing shape as it propagates, but it may or may not be accompanied by a shock wave front, with the associated discontinuities.
See compression wave.


Copyright 2022 American Meteorological Society (AMS). For permission to reuse any portion of this work, please contact permissions@ametsoc.org. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act (17 U.S. Code § 107) or that satisfies the conditions specified in Section 108 of the U.S.Copyright Act (17 USC § 108) does not require AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a website or in a searchable database, or other uses of this material, except as exempted by the above statement, require written permission or a license from AMS. Additional details are provided in the AMS Copyright Policy statement.