Here, the starred quantities are evaluated at the reference temperature T* appropriate to the reference enthalpy h* discussed previously. Wilhite et al. (1984) point out that that the following regimes based on V′ appeared to apply:
• V′<0.007 corresponds to continuum flow
• 0.007<V′<0.07 corresponds to the viscous interaction regime
• 0.07<V′<5 corresponds to the transitional flow regime
• V′>5 corresponds to the free molecular flow regime
In particular, as V′ rises above 0.007, L/D tends to drop and other aerodynamic performances measures are similarly compromised.
The parameter is shown as a function of M in Figure 8.38 ...