{"id":14438,"date":"2017-05-22T11:22:43","date_gmt":"2017-05-22T11:22:43","guid":{"rendered":"http:\/\/sitepourvtc.com\/?page_id=14438"},"modified":"2022-10-24T07:55:09","modified_gmt":"2022-10-24T07:55:09","slug":"external-flow","status":"publish","type":"page","link":"https:\/\/sitepourvtc.com\/nuclear-engineering\/fluid-dynamics\/external-flow\/","title":{"rendered":"External Flow"},"content":{"rendered":"
In fluid dynamics, external flow<\/strong> is such a flow in which boundary layers develop freely, without constraints imposed by adjacent surfaces.<\/span><\/div><\/div>\n

In comparison to internal flow<\/a>, entrance flows and external flows feature highly viscous effects confined to rapidly growing \u201cboundary layers<\/strong>\u201d in the entrance region or thin shear layers along the solid surface. Accordingly, there will always exist a region of the flow outside the boundary layer<\/strong>. In this region, velocity, temperature, and\/or concentration do not change in, and their gradients may be neglected.<\/span><\/p>\n

This effect causes the boundary layer to be expanding, and the boundary-layer thickness relates to the square root of the fluid\u2019s kinematic viscosity.<\/span><\/strong><\/p>\n

This is demonstrated in the following picture. Far from the body, the flow is nearly inviscid. It can be defined as the fluid flow around a body that is completely submerged in it.<\/span><\/strong><\/p>\n

\"Boundary<\/a><\/p>\n

<\/span> Classification of Flow Regimes<\/div>
From a practical engineering point of view, the flow regime can be categorized according to several criteria<\/strong>.<\/p>\n

All fluid flow<\/strong> is classified into one of two broad categories or regimes. These two flow regimes are:<\/p>\n