Generated, based on ENGR271 2026 Q2(c) "calculate and justify" style
Air at 101.3 kPa and 20 deg C has a mean free path . At constant temperature, is inversely proportional to pressure. Air flows through a tube of internal diameter 10 mm connected to a vacuum system.
- (a)[3]Calculate the Knudsen number at atmospheric pressure and state the flow regime.
- (b)[4]Determine the pressure below which the continuum hypothesis is no longer valid for this tube.
- (c)[3]The system is pumped down to 10 Pa. Calculate , state the regime, and explain whether the no-slip condition and the standard pipe-flow results of this module can be used.