CATALOG DATA:
Unsteady flows, unsteady aerodynamics of airfoils, cascades and finite wings, acoustics in moving media, aerodynamic sound, Lighthill's analogy, far field conditions, Kirchhoff's method, numerical methods in aeroacoustics.TEXTBOOK:
NoneGOALS:
To provide advanced students with a review of current ideas related to unsteady aerodynamics of lifting surfaces and aeroacoustics.Topics:
- Steady and Unsteady Flows: Bluff and streamlined bodies, separated and attached flows, incompressible, subsonic, transonic and supersonic flows, characteristics of unsteady flows, relations to aeroacoustics and aeroelasticity.
- Equations of Motion of Unsteady Flows: Equation of continuity, kinematics of flow field, momentum and energy equations, boundary conditions on solid surface in motion, kinetic energy, virtual mass, pressure equation in moving frame, forces on moving bodies, cylinder moving in unbounded fluid, irrotational motion, sources and vortices, vortex sheet, vortex street, large structure rotational motion.
- Linear Unsteady Aerodynamics: Some mathematical tools, splitting theorem, acoustic, rotational and entropic modes, Wagner problem, Theodorsen problem, Sears problem, indicial method, effect of compressibility, Possio equation.
- Unsteady Aerodynamics of Loaded Airfoils and Cascades: Large structure nonuniform flows, rapid distortion approximation, mathematical and numerical methods, oscillating airfoils, airfoil in a gust, effects of loading, effects of compressibility, three-dimensional flows, cascade flows, solidity, stagger and interblade phase angle.
- Unsteady Aerodynamics of Separated Airfoils and Cascades: Topology of flow at various Reynolds numbers, unsteady separation, aerodynamic hysteresis, mathematical and numerical methods, receptivity.
- Unsteady Aerodynamics of Finite Wings: Finite wing effects, panel methods, delta wings.
- Acoustics in Moving Media: Convective wave equation, elementary solutions, sources, dipoles, quadrupoles, acoustic intensity and energy, sound from a moving source at subsonic and supersonic speeds, sound from a fluctuating force, sound from turbulence, effect of solid boundaries.
- Aerodynamic Sound Ü Lighthill's Acoustic Analogy: Free-space solutions, jet noise, effect of solid boundaries, Williams-Hawkins equation, effects of uniform flows, application to fan and compressor noise.
- Aerodynamic Sound as the Far Field of Unsteady Flows: Sound from a thin airfoil in a gust, numerical methods, far field boundary conditions, Kirchhoff method, sound from loaded airfoils and cascades.
ABET category content as estimated by faculty member who prepared the course description:
Engineering Science: 3 credits or 100%
Engineering Design: 0 creditsPrepared by: Professor Hafiz Atassi
Last Update: April 13, 1992
Direct comments, questions, and corrections to amedept@nd.edu