CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   Main CFD Forum (http://www.cfd-online.com/Forums/main/)
-   -   Potential Flow : Laminar or Turbulent (http://www.cfd-online.com/Forums/main/2281-potential-flow-laminar-turbulent.html)

Brindaban Ghosh June 24, 2000 02:56

Potential Flow : Laminar or Turbulent
 
For potential flow, viscous force term is identically zero. Therefore, Reynolds number is automaticallly infinite. Therefore, whether potential flow is laminar or turbulent.

John C. Chien June 24, 2000 04:02

Re: Potential Flow : Laminar or Turbulent
 
(1). The Reynolds number is associated with the viscous terms as (1/Re). (2). So, as Re goes to infinity, (1/Re) goes to zero. In this case, it is still called high RE number flow. This is because, the corresponding boundary layer thickness will goes to zero in the limit. But it is still there. (3). If we drop the viscous terms all together from the equation, then, physically, the effects of viscous terms disappear. They are not there any more from the begining. (as far as the equation is concern) (4). In the equation, where the viscous terms are no longer there, is call inviscid equation. You don't have the viscous terms, so you don't have the Reynolds number. It can be Euler equation, or full potential equation or linearlized potential equation. You can't attach the Reynold number to these equations. (5). So, the flow with Reynolds number goes to infinity is still considered as viscous flow, because the boundary condition is still the non-slip condition. (6). On the other hand, in the inviscid equations, the boundary condition must be slip condition with flow parallel to the wall locally. (7). So, it must be either the inviscid flow, the laminar viscous flow, or the turbulent viscous flow.(that is, laminar flow = laminar viscous flow)


All times are GMT -4. The time now is 21:50.