Behavior of Gases at Rest: Fluid Statics
In the previous sections, introductions to the problem of modeling fluid flows in aerodynamics and some calculations for aerodynamic forces are presented. At several points, information about properties of the atmosphere are required in completing the calculations. For example, it is frequently the case that we need to know the value of the atmospheric temperature, density, or pressure when estimating the magnitude of aerodynamic forces or evaluating propulsion-system performance. This need provides the opportunity to gain further practice in handling fluid-mechanics modeling
and, in the process, to review methods for representing atmospheric effects. Because only the simplest type of physical relationship is involved, we can accomplish this now without using the more sophisticated modeling needed in subsequent problems. Only the ideas of statics and the ideal gas equation are required.