Question

A water blaster consists of a pump and a petrol water motor. In the pump the pressure of the s from 101.3 kPa to 30 MPa. The outlet temperature is 40°C. Determine the velocity of water at the outlet assuming the inlet velocity is negligible and the system is adiabatic. The specific work into the pump is 0.5 kJ/kg. Calculate the velocity at the outlet.

Answer 1

Answer:246.57 m/s

Explanation:

Given data

$inlet pressure\left ( P_1\right )=101.3KPa$

$outlet pressure\left ( P_2\right )=300 MPa$

$Outlet Temperature\left ( T_0\right )=40^{\circ}C$

$Specific Work into the pump=0.5 KJ/kg$

Applying Steady flow energy equation

$h_1+\frac{C_1^2}{2000}\frac{gz_1}{1000}+Q=h_2+\frac{C_2^2}{2000}\frac{gz_2}{1000}$+W

$C_1=0$

$Z_1&Z_2$ is zero

Q=0

$h_1-h_2-W=\frac{C_2^2}{2000}$

$\frac{C_2^2}{2000}=\int \nu dP+W$

$\frac{C_2^2}{2000}$=$\frac{P_1-P_2}{1000}-\left ( -0.5\right )$

$\frac{C_2^2}{2000}$=30.39

$C_2^2=60,797.36$

$C_2=246.57m/s$