Final answer:
The Reynolds number is used to determine the flow regime in a pipe, which is then utilized in the Darcy-Weisbach equation to calculate the friction factor. Poiseuille's law is applied to laminar flow in pipes. Manning's equation is not used for pipe flow friction factor determination.
Step-by-step explanation:
The method used for determining the friction factor in pipe flow experiments is closely related to the Reynolds number, which is a dimensionless quantity used to determine the flow regime of the fluid within a pipe. The flow can be either laminar or turbulent. Laminar flow is smooth and orderly, typically occurring at Reynolds numbers below 2000, while turbulent flow is chaotic and occurs at Reynolds numbers above 3000.
To calculate the Reynolds number for an object moving through a fluid, we can use the equation:
NR = (velocity × characteristic length × density) / viscosity
Once the Reynolds number is calculated, we can assess whether the flow is laminar or turbulent. The Darcy-Weisbach equation provides a method to determine the pressure drop in pipes based on the friction factor, pipe length, fluid velocity, inside pipe diameter, and fluid density which is influenced by the type of flow determined by the Reynolds number. In a pipe flow experiment, the Darcy-Weisbach equation and the Moody chart are commonly used together to find the friction factor once the Reynolds number and the roughness of the pipe are known.
The Hagen-Poiseuille equation, also known as the Poiseuille's law, is specifically applicable for laminar flow through circular pipes and is based on the assumptions of steady, incompressible flow that has a parabolic velocity profile due to a constant viscosity.
Manning's equation is another empirical formula used to calculate the flow of water in open channels and is not used for determining the friction factor in pipe flow experiments.
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