Hagen-Poisseuille equation

For all capillary instruments the time t needed for a certain volume V of the solution to flow through a thin capillary of length l and radius R is measured. Assuming a laminar flow, the Hagen-Poisseuille equation can be applied, leading to... 

The capillary pressure will have an effect only at high capillary numbers when the curvatures of the front and rear ends of the Taylor bubble are not symmetrical. At low velocity and in narrow channels, the frictional pressure drop is viscosity-dominant and can be calculated using the Hagen-Poisseuille equation... 

As the two-phase systems form dispersed and continuous phase. Equation 7.53 can be used. It requires single-phase pressure drop and k. The singlephase pressure drop can be calculated using Hagen-Poisseuille equation (Equation 7.42). 

At a pressure below P j (=1 1 r aJ the membrane is impermeable. At the largest pores become permeable, and as the pressure increases smaller md smailer pores become permeable. Finally, when a pressure is reached, the smallest pores become permeable. The flux at a certain pressure is due to the contribution of all pores that are available, i.e. assuming cylindrical pores the Hagen-Poisseuile equation can be applied in... 

Ihe permeability method can be used both for microfiltration and ultrafiltiatimi membranes. As with most methods of characterisation, one of the main problems encountered is the pore geometry. As mentioned above, the Hagen-Poisseuille equation assumes that the pores are cylindrical whereas the Kozeny-Cannan equation assumes that the pores are interstices between close-packed spheres. Such pores are not commonly found in sjoithetic membranes. 

For laminar flow of fluid through a pipe experiencing viscous drag. Carman (1937, 1956) applied the Hagen-Poisseuille Equation... 

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