Question

Along the streamline of the conical flow, the total enthalpy stays constant.

(a) True

(b) False

The question was posed to me in unit test.

Asked question is from Quantitative Formulation in portion Linearized and Conical Flows of Aerodynamics

Answer 1

The correct choice is (a) True

To explain: The energy equation is given by

ρ\(\frac {Dh_0}{Dt} = \frac {∂p}{∂t}\) + p\( \dot {q}\) + ρ(f.V)

Where \(\frac {Dh_0}{Dt}\) is the total derivative of total enthalpy

p is the pressure

\( \dot {q}\) is per rate of heat added/removed

f.V is body forces

According to Taylor – Maccoll’s assumptions, the flow is said to be steady (\(\frac {∂}{∂t}\) = 0), adiabatic (\( \dot {q}\) = 0), inviscid and has no external body forces (f.V = 0). Thus, the equation reduces to

ρ\(\frac {Dh_0}{Dt}\) = 0

Which on integrating gives us h0 = const.