Principles of Flight
To all aspiring ATPL PoF candidates:
Bernoulii told us that the sum of the energies in a gas is constant.
The Equation of Continuity tells us that air mass flow is a constant. Therefore in a tube, if the cross-sectional area decreases, the velocity will increase.
Therefore, ignoring compressibility, gas heat energy and gas potential energy, if velocity increases then pressure decreases.
Consider a windsock. It is convergent with respect to the airflow.
If this is so, then velocity will increase and pressure will decrease.
Question. Why therefore does the windsock not collapse.....?
David