Air at 1.3 bar, 500 k and a velocity of 40 m/s enters a nozzle operating at steady state and expands adiabatically to the exit, where the pressure is 0.85 bar and velocity is 250 m/s. for air modeled as an ideal gas with k = 1.4, determine for the nozzle: (a) the temperature at the exit, in k, and (b) the percent isentropic nozzle efficiency.

Given:

Pressure, P = 1.3 bar

Temperature, T = 500 K

velocity, v = 40 m/s

Pressure, P' = 0.85 bar

velocity, v' = 250 m/s

k = 1.4

Solution:

Now, we know that:

specific heat at constant pressure,

specific heat at constant volume, = 1.005 KJ/kgK

k =

(a) To calculate temperature at exit, T'

Using steady flow Eqn:

                 (1)

where

h = enthalpy =

h'=

Now, from eqn (1)-

T' = 469.70 K

(b) To calculate % isentropic nozzle efficiency:

Using the relation:

⇒

Now,

% isentropic nozzle efficiency,

%   %

%

the independent variable, the one that is intentionally manipulated, is whether or not the car hits the barrier.

the dependent variable, the one that you measure the response in, is the distance that the washers travel.

the correct choice is a .

do not post any more test or exam questions on