well , i have found that the f for rough pipe is 0.017 , nut i am not sure how to find f for smooth pipe using von karman and Prandlt laws ... for smooth pipe , i have 1 / ( surd f ) = 2 log [(3.72 x 10^5) (surd f ) / 2.51 ]BvU said:I was going to propose you do both (assuming some reasonable ##e## for galvanized ion pipe ) and compare ...
On the other hand, you do have the data to calculate Re so I certainly wouldn't leave out that one...
so , do you have any comment on this question / which is correct ?Nidum said:
The Von Karman and Prandtl laws are two fundamental laws in fluid dynamics that describe the behavior of boundary layers, which are thin layers of fluid that form near a solid surface in a moving fluid.
The Von Karman law states that the ratio of the shear stress to the square root of the fluid's density is constant throughout the boundary layer, regardless of the fluid's viscosity. This law is also known as the "law of the wall" because it describes the shear stress near the wall of the boundary layer.
The Prandtl law states that the thickness of the boundary layer is proportional to the square root of the distance from the leading edge of the object. This law is also known as the "law of the boundary layer thickness" and is used to predict the thickness of the boundary layer at different points along an object.
The Von Karman and Prandtl laws are related because they both describe different aspects of boundary layers and are used to analyze the behavior of fluids near a solid surface. The Von Karman law describes the shear stress near the wall of the boundary layer, while the Prandtl law describes the thickness of the boundary layer.
The Von Karman and Prandtl laws have numerous applications in fluid dynamics, including the design of aerodynamic surfaces for aircraft, the prediction of drag and lift forces, and the analysis of heat and mass transfer in boundary layers. These laws are also used in the development of wind turbines, automobiles, and other vehicles that interact with fluid flow.