Question 3
Hot gasses from a combustion chamber flows isentropically through a diverging-converging
nozzle such that the flow at the exit of the converging nozzle is supersonic. The nozzle has a
throat area of 0.1 m², and an exit area of 4 m². The temperature of the fluid at the throat
is 3000 K, and the density of the fluid within the combustion chamber is 27.8 kg/m³. If the
fluid has a ratio of specific heats of k = 1.3 and a molar mass of 11 g/mol, calculate the force
imparted by the fluid at the exit of the nozzle. You may assume that the fluid is an ideal gas.
[6 marks]
[Hint: From your previous fluids course, you should know that through a momentum balance,
the force imparted by the fluid is $F = \rho AV^2$].