Answer to Question #295547 in Molecular Physics | Thermodynamics for Losifer

Question

A blower handles 1kg/s of air at 20^(@)C and consumes a power of 15kW.The inlet and outlet velocities of air are 100m/s and 150m/s respectively.Find the exit air temperature assuming adiabatic conditions.Take c_(p) of air is 1.005kJ/kg-K.

Answer 1

Solution;

Given;

$\dot{m}=1kg/s$

$T_1=20^oc=293$

$W=15kW$

$V_1=100m/s$

$V_2=150m/s$

$c_p=1.00kJ/kgK$

The process is adiabatic;

$Q=0$

Apply steady flow energy equation;

$\dot{m}(h_1+\frac{V_1^2}{2000})+W=\dot{m}(h_2+\frac{V_2^2}{2000})$

where;

$h=c_pT$

By direct substitution;

$[(1.005 \times 293)+\frac{100^2}{2000}]+15=1[(1.005\times T_2)+\frac{150^2}{2000})$

$314.465=1.005T_2+11.25$

$T_2=301.7064K$ or $28.71^oc$