Question

Due to rise in temperature, the viscosity and unit weight of percolating fluid are reduced to 70% and 90% respectively. Other things being constant, the change in coefficient of permeability will be

• A. 20.0%
• B. 28.6%
• C. 63.0%
• D. 77.8%

Answer 1

The correct option is B 28.6%

Taylor's equation based on Poiseuille's law for laminar flow through circular tube is given by

$k=\frac{\gamma }{\mu }\frac{e^3}{1+e}C{D}_s^2$

$\therefore$ Change in coefficient of permeability,

$k^{\prime }=\frac{0.9\gamma }{0.7\mu }\frac{e^3}{1+e}C{D}_s^2$

$\therefore$ $\frac{k^{\prime }}{k}=\frac{0.9}{0.7}\times 100=128.57\%$

Change = 28.57%