# Low Speed Aerodynamics

Most pioneers learned the "disciplines" of engineering through the hard route of designing devices and systems. We try to capture this spirit by taking the learner through the process of conceptually designing a flight vehicle. In the process, we explore the gateways to the various disciplines of aerospace engineering, each leading to deep resources of knowledge and experience. Prepare for liftoff. First year undergraduates, fresh out of high school, find themselves designing airliners and This is the discipline that defines the methods of aerodynamics. Starting with the laws of Physics, and the continuum model of fluid behavior, the conservation equations of fluid dynamic are derived and specialized to the needs for aircraft analysis. The "potential" method is related to the conservation equations, and reduced to the Laplace equation as describing the velocity field in incompressible, irrotational aerodynamics. Elementary solutions for the Laplace equation are related to physical notions. The Helmholtz vortex theorems enable models of vortex interactions and ground effect. The "thin airfoil theory" derives simple results for the ideal lift curve slope of an airfoil. For high aspect ratio, straight (i.e., unswept ) wings, Prandtl's Lifting Line theory and the Glauert Series solution to the theory are easily derived and widely used to obtain practical solutions for wing load distributions. At the other end of the aspect ratio spectrum, slender wing theory enables estimation of a lower limit on lift curve slope. Finally, a section on viscous flow provides simple solutions to the Navier-Stokes equations, and empirical methods to calculate boundary layer parameters in order to capture skin friction drag and the occurrence of flow separation.

Introduction to Aerodynamics: Some results to provide physical intuition.

Laws of Physics and Fluid Dynamics.
Conservation Equations in Integral Form.
Specializing the Conservation Equations for aerodynamics.
The Potential Flow Method
Vortex Interactions, and Thin Airfoil Theory.
Finite Wings.
Prandtl's Lifting Line Method
Viscous Flow
Practical Methods and Data Sources

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