Question

The quantity of flow for circular tube with respect to the hydraulic radius is given by ________

(a) \(q=\frac{1}{2}\frac{γ_w R_H^2}{η} \)

(b) \(q=\frac{1}{2}\frac{γ_w R_H^2}{η}ia\)

(c) \(q=\frac{1}{2}\frac{γ_w R_H^2}{η}i\)

(d) \(q=\frac{1}{2}\frac{γ_w R_H^2}{η}a \)

I got this question in unit test.

I would like to ask this question from Poiseuille’s Law topic in portion Permeability of Geotechnical Engineering I

Answer 1

The correct option is (b) \(q=\frac{1}{2}\frac{γ_w R_H^2}{η}ia\)

Best explanation: The quantity of flow for the capillary tube of any geometrical shape is given by,

\(q=C_S \frac{γ_w R_H^2}{η}ia\), where Cs is the shape constant.

For circular tube Cs=1/2

\( ∴ q=\frac{1}{2}\frac{γ_w R_H^2}{η}ia.\)