Question

Two pipes with 1 meter diameters join to become one pipe with 2 meter diameter. Water was flowing in first pipe at 500 kg/s and oil was flowing in the second pipe with average velocity of 0.8 m/s. Oil mass density is 1500 kg/s. What will be the mass flow rate at the exit of the 2 meter diameter pipe?

Answer 1

Answer:

The mass flow rate at the exit of the 2 meter diameter pipe is 1442 kg/s

Explanation:

If the oil is flowing in the 1m diameter pipe at 0.8 m/s, we can calculate the flow as

$Q=\bar{v}*A=\bar{v}*(\pi/4*D^{2} )=0.8m/s*0.785m^{2} =0.628m^{3}/s$

The mass flow is

$M=\rho*Q=1500 kg/m3*0.628m3/s=942kg/s$

The mass flow rate at the exit of the 2 meter diameter pipe is

$M=M_w+M_o=500 kg/s+942kg/s=1442kg/s$