Question

What is the value of derivative of flow field along characteristic line?

(a) Zero

(b) Indeterminate

(c) One

(d) 0.5

The question was asked by my school principal while I was bunking the class.

My question is taken from Two Dimensional Irrotational Flow topic in portion Numerical Techniques for Steady Supersonic Flow of Aerodynamics

Answer 1

The correct option is (b) Indeterminate

To explain: If we consider the direction along the flow field and take the derivatives of these flow properties, the value takes the form of \(\frac {numerator}{denominator} = \frac {0}{0}\) or indeterminate form along the characteristic lines.