Search results
Results from the WOW.Com Content Network
Using this term, one can calculate many things in the same way as for a round tube. When the cross-section is uniform along the tube or channel length, it is defined as [1] [2] =, where A is the cross-sectional area of the flow, P is the wetted perimeter of the cross-section.
A is the cross-sectional area of pipe. The equation does not hold close to the pipe entrance. [8]: 3 The equation fails in the limit of low viscosity, wide and/or short pipe. Low viscosity or a wide pipe may result in turbulent flow, making it necessary to use more complex models, such as the Darcy–Weisbach equation.
Diagram showing definitions and directions for Darcy's law. A is the cross sectional area (m 2) of the cylinder. Q is the flow rate (m 3 /s) of the fluid flowing through the area A. The flux of fluid through A is q = Q/A. L is the length of the cylinder. Δp = p outlet - p inlet = p b - p a.
As the air in the tube moves into and around the smaller cross-sectional area between the pod and tube, the air flow must speed up due to the continuity principle. If the pod is travelling through the tube fast enough, the air flow around the pod will reach the speed of sound, and the flow will become choked , resulting in large air resistance ...
In the case of a non-circular cross-section of a pipe, the same formula can be used to find the entry length with a little modification. A new parameter “hydraulic diameter” relates the flow in non-circular pipe to that of circular pipe flow. This is valid as long as the cross-sectional area shape is not too exaggerated.
Cross sectional area of a trapezoidal open channel, red highlights wetted perimeter Change of wetted perimeter (blue) of trapezoidal canal as a function of angle ψ. The wetted perimeter is the perimeter of the cross sectional area that is "wet". [ 1 ]
At cross section 1, the mean flow velocity is equal to v 1, the pressure is p 1 and the cross-sectional area is A 1. The corresponding flow quantities at cross section 2 – well behind the expansion (and regions of separated flow) – are v 2, p 2 and A 2, respectively.
The Gauckler–Manning formula states: = / / where: V is the cross-sectional average velocity (dimension of L/T; units of ft/s or m/s); n is the Gauckler–Manning coefficient. Units of n are often omitted, however n is not dimensionless, having dimension of T/L 1/3 and units of s/m 1/3.