Elements of Vorticity Aerodynamics

This book opens with a discussion of the vorticity-dynamic formulation of the low Mach number viscous flow problem. It examines the physical aspects of the velocity and the vorticity fields, their instantaneous relationship, and the transport of vorticity in viscous fluids for steady and unsteady flows. Subsequently, using classical analyses it explores the mathematical aspects of vorticity dynamics and issues of initial and boundary conditions for the viscous flow problem. It also includes the evolution of the vorticity field which surrounds and trails behind airfoils and wings, generalizations of Helmholtz’ vortex theorems and the Biot-Savart Law. The book introduces a theorem that relates the aerodynamic force to the vorticity moment and reviews the applications of the theorem. Further, it presents interpretations of the Kutta-Joukowski theorem and Prandtl’s lifting line theory for vorticity dynamics and discusses wake integral methods. The virtual-mass effect is shown to be the seminal event in unsteady aerodynamics and a simple approach for evaluating virtual-mass forces on the basis of vorticity dynamics is presented.The book presents a modern viewpoint on vorticity dynamics as the framework for understanding and establishing the fundamental principles of viscous and unsteady aerodynamics. It is intended for graduate-level students of classical aerodynamics and researchers exploring the frontiers of fully unsteady and non-streamlined aerodynamics.

James C. Wu, Professor Emeritus of Aerospace Engineering of Georgia Institute of Technology, Chairman professor of Shanghai Jiao Tong University and Honorary Professor of the Nanjing University of Aeronautics and Astronautics and of the Beijing institute of Aerodynamics, received his Ph. D. in Mechanical Engineering from University of Illinois. He held teaching and research positions at several universities and research establishments, including Massachusetts Institute of Technology, Gonzaga University, European Atomic Ispra Energy Research Center and Douglas Aircraft Company, where he served as Chief of Aerothermodynamics, before taking his post at Georgia Tech. He is Chief Scientist of Applied Aero, LLC and Chairman of Board of Directors of the Aerospace Science Foundation in the U. S. Professor Wu published extensively in leading technical journals and served on editorial boards and technical committees of many international scientific and engineering journals and societies. He served as consultant in aerodynamics to many academic, industrial, and governmental entities at various places of the world. He was awarded Wessex Institute of Technology (England) Distinguished Scholar Award in 1994 for his research contributions to computational aerodynamics and Friendship Award (China) in 1999 for his contributions to aerospace education. Publication List [1] Ren W., Hu H., Liu H., Wu J.C., An Experimental Investigation on the Asymmetric Wake Formation of an Oscillating Airfoil. AIAA-2013-0794, 2013. [2] Wu J. C. Vorticity-Moment Theorem of Aerodynamics Revisited. International Retreat on Vorticity Aerodynamics. Beijing, August 22, 2009. [3] Wu J. C. Elements of Vorticity Aerodynamics. Tsinghua University Press, Beijing, 2005. [4] Wu J. C. Wang C.M., McAlister K.W., Wake-Integral Determination of Aerodynamic Drag, Lift and Moment in Three-Dimensional Flows. AIAA 2002-0555,2002. [5] Kim G. Wang C.M., Wu J.C., Computation Of Flow Over Wings Using An Integro-Differential Formulation, AIAA-96-1960,1996. [6] Wu J.C., Singh Jatinder, Unsteady Aerodynamics of Nonrigid Bodies Undergoing Time-dependent Motions/Deformations - A Simplified Zonal Approach.AIAA-94-1889,1994. [7] Wang C.M., Wu J. C., Qian P., Unsteady Aerodynamics of Rapidly Pitched Flat Plate Wings. AIAA-91-3262, 1991. [8] Wang C.M., Wu J.C., Tung C., A Numerical Study of General Viscous Flows Around Multi-Element Airfoils.AIAA-90-0572,1990. [9] Wang C. M., Wu J. C., A Numerical Method for Three-Dimensional Viscous Flows. AIAA-90-0236, 1990. [10] Tuncer, I.H., Wu, J.C., Wang, C.M., Theoretical and Numerical Studies of Oscillating Airfoils. AIAA Journal, 28(9):1615-24, 1990. [11] Tuncer I.H., Wu J.C., Wang C.M., Theoretical and Numerical Studies of Oscillating Airfoils.AIAA-89-0021,1989. [12] Hsu A.T., Wu J.C., Vortex Flow Model for the Blade-Vortex Interaction Problem, AIAA Journal,26(5):622-623,1988. [13] Wu J.C., Singh Jatinder, Unsteady Aerodynamics of Non-Rigid Bodies - A Nove