Complex Analysis
Riemann Mapping Theorem
Boeing uses conformal maps for wing profiles: the Joukowski transform underlies the aerodynamics of the 737 MAX, designed in the 1960s without CFD.
- **Aerodynamics:** Joukowski transform gives analytic flow solution around any airfoil via the cylinder solution.
- **Electrostatics:** conformal maps solve Laplace problems for complex geometries (capacitors, electrodes).
- **Quantum conductance (NIST):** Hall resistance on graphene computed via conformal mapping (van der Pauw method).
Conformal Maps
Boeing uses conformal maps to design airfoil profiles: the Joukowski transform converts the analytically solvable flow around a cylinder into flow around a wing. The 737 MAX profile was developed using this method as far back as the 1960s.
What does a conformal map preserve?
Riemann Mapping Theorem
In 2D quantum conductance measurements of graphene (NIST 2019), the Hall resistance is computed via conformal mapping of an arbitrary sample plate onto a standard square. The Riemann mapping theorem guarantees the existence of such a map.
Which domains are conformally equivalent to the unit disk, by the Riemann mapping theorem?
Key ideas
- **Conformality:** analytic f with f'(z0)!=0 preserves angles. Scale |f'(z)|, rotation arg f'(z).
- **Joukowski transform:** w=z+R^2/z maps circles to airfoil profiles. Mobius: circles map to circles.
- **Riemann mapping theorem:** any simply connected U (strictly in C) is conformally equivalent to the disk. Normalization gives uniqueness.