{"id":330,"date":"2022-11-09T03:49:27","date_gmt":"2022-11-09T03:49:27","guid":{"rendered":"https:\/\/successrouter.com\/articles\/?p=330"},"modified":"2022-11-09T03:49:29","modified_gmt":"2022-11-09T03:49:29","slug":"critical-velocity","status":"publish","type":"post","link":"https:\/\/successrouter.com\/articles\/critical-velocity\/","title":{"rendered":"Critical velocity"},"content":{"rendered":"\n<p><\/p>\n\n\n<h3 class=\"wp-block-heading\" id=\"critical-velocity\">Critical velocity<\/h3>\n\n\n<p>The critical velocity of a liquid is that limiting value of its velocity of flow upto which the flow is streamlined and above which the flow becomes turbulent.<\/p>\n\n\n\n<p>The critical velocity v<sub>c<\/sub> of a liquid flowing through a tube depends on<\/p>\n\n\n\n<p>(i)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 coefficient of viscosity of the liquid (\u03b7)<\/p>\n\n\n\n<p>(ii)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; density of the liquid (r)<\/p>\n\n\n\n<p>(iii) diameter of the tube (D)<\/p>\n\n\n\n<p>Let v<sub>c <\/sub>= k \u03b7<sup>a<\/sup> r<sup>b<\/sup> D<sup>c<\/sup><\/p>\n\n\n\n<p>where k is a dimensionless constant. Writing the above equation in dimensional form, we get<\/p>\n\n\n\n<p>[M<sup>0<\/sup>LT<sup>-1<\/sup>] = [ML<sup>-1<\/sup>T<sup>-1<\/sup>]<sup>a<\/sup> [ML<sup>-3<\/sup>]<sup>b<\/sup> [L]<sup>c<\/sup><\/p>\n\n\n\n<p>[M<sup>0<\/sup>LT<sup>-1<\/sup>] = [M<sup>a + b <\/sup>L<sup>-a &#8211; 3b + c<\/sup>T <sup>&#8211; a<\/sup>]<\/p>\n\n\n\n<p>Equating powers of M, L and T, we get<\/p>\n\n\n\n<p>a + b = 0<\/p>\n\n\n\n<p>&#8211; a &#8211; 3b + c = 1<\/p>\n\n\n\n<p>&#8211; a = -1<\/p>\n\n\n\n<p>On solving, we get a = 1, b = -1, c = -1<\/p>\n\n\n\n<p>\u2234 v<sub>c<\/sub> = k \u03b7 r<sup>-1<\/sup> D<sup>-1<\/sup> = <img loading=\"lazy\" decoding=\"async\" width=\"14\" height=\"28\" src=\"\">k \u03b7 \/ r D<\/p>\n\n\n\n<p>Clearly, the critical velocity v<sub>c<\/sub> will be large if \u03b7 is large, and p and D are small. So, we can conclude that<\/p>\n\n\n\n<p>(i)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; The flow of liquids of higher viscosity and lower density through narrow pipes tends to be streamlined.<\/p>\n\n\n\n<p>(ii)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; The flow of liquids of lower viscosity and higher density through broad pipes tends to become turbulent, because in that case the critical velocity will be very small.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Critical velocity The critical velocity of a liquid is that limiting value of its velocity of flow upto which the flow is streamlined and above which the flow becomes turbulent. The critical velocity vc of a liquid flowing through a tube depends on (i)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 coefficient of viscosity of the liquid (\u03b7) (ii)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; density of the &#8230; <a title=\"Critical velocity\" class=\"read-more\" href=\"https:\/\/successrouter.com\/articles\/critical-velocity\/\" aria-label=\"More on Critical velocity\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[69],"_links":{"self":[{"href":"https:\/\/successrouter.com\/articles\/wp-json\/wp\/v2\/posts\/330"}],"collection":[{"href":"https:\/\/successrouter.com\/articles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/successrouter.com\/articles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/successrouter.com\/articles\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/successrouter.com\/articles\/wp-json\/wp\/v2\/comments?post=330"}],"version-history":[{"count":1,"href":"https:\/\/successrouter.com\/articles\/wp-json\/wp\/v2\/posts\/330\/revisions"}],"predecessor-version":[{"id":331,"href":"https:\/\/successrouter.com\/articles\/wp-json\/wp\/v2\/posts\/330\/revisions\/331"}],"wp:attachment":[{"href":"https:\/\/successrouter.com\/articles\/wp-json\/wp\/v2\/media?parent=330"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/successrouter.com\/articles\/wp-json\/wp\/v2\/categories?post=330"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/successrouter.com\/articles\/wp-json\/wp\/v2\/tags?post=330"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}