The difference in water surface levels in the two tanks is 18 m. Determine the rate of flow of water if coefficients of friction are 0.0075, 0.0078 & 0.0072 respectively (consider minor losses).

Given:

For the three pipes in series connected between two tanks

Now, Applying Bernoulli’s Principle between the liquid surfaces in the two tanks, $\frac{P_1}{ρg}+\frac{v_1^2}{2g}+Z_1=\frac{P_2}{ρg}+\frac{v_2^2}{2g}+Z_2+h_l$

Now,

Assuming both the tanks are open to atmosphere ⇒$P_1=P_2$

Assuming the tanks are infinitely large such that the water level does not change as flow …