Allen Plotkin

Bio: Allen Plotkin is an academic researcher from San Diego State University. The author has contributed to research in topics: Aerodynamics & Incompressible flow. The author has an hindex of 15, co-authored 62 publications receiving 2717 citations. Previous affiliations of Allen Plotkin include White Oak Conservation & University of Maryland, College Park.

Low-Speed Aerodynamics

Abstract: Low-speed aerodynamics is important in the design and operation of aircraft flying at low Mach number, and ground and marine vehicles. This 2001 book offers a modern treatment of the subject, both the theory of inviscid, incompressible, and irrotational aerodynamics and the computational techniques now available to solve complex problems. A unique feature of the text is that the computational approach (from a single vortex element to a three-dimensional panel formulation) is interwoven throughout. Thus, the reader can learn about classical methods of the past, while also learning how to use numerical methods to solve real-world aerodynamic problems. This second edition has a new chapter on the laminar boundary layer (emphasis on the viscous-inviscid coupling), the latest versions of computational techniques, and additional coverage of interaction problems. It includes a systematic treatment of two-dimensional panel methods and a detailed presentation of computational techniques for three-dimensional and unsteady flows. With extensive illustrations and examples, this book will be useful for senior and beginning graduate-level courses, as well as a helpful reference tool for practising engineers.

Low-speed aerodynamics : from wing theory to panel methods

Abstract: Introduction and Background. Fundamentals of Inviscid, Incompressible Flow. General Solution of the Incompressible, Potential Flow Equations. Small Disturbance Flow Over Three Dimensional Airfoils. Exact Solutions with Complex Variables. Perturbation Methods. Three-Dimensional Small Disturbance Solutions. Numerical (Panel) Methods. Singularity Elements and Influence Coefficients. Two-Dimensional Numerical Solutions. Three-Dimensional Numerical solutions. Unsteady Aerodynamics. Advanced Topics. Airfoil Integrals. Singularity Distribution Integrals. Principle Value of the Lifting Surface Integral. Sample Computer Programs.

Slender wing in ground effect

Abstract: Determination analytique du coefficient de portance d'une aile mince en effet de sol. Comparaison avec les resultats numeriques obtenus par la methode des panneaux

Thickness-Induced Lift on a Thin Airfoil in Ground Effect

Abstract: HERE has been renewed interest recently in the calculation of the aerodynamic characteristics of a wing flying in proximity to the ground. In fact, some vehicles have been designed to take advantage of the positive aspects of ground effect. For the idealized problem of two-dimension al steady potential flow past a flat plate airfoil in the presence of a plane wall, Tomotika et al.l and Havelock2 used conformal mapping to obtain an exact solution. Green3 obtained a solution for an airfoil of general shape in ground effect. In Refs. 1-3, expansions are also given in chord-to-wall clearance ratio. More recently, accurate numerical solutions using panel methods (surface singularity distributions) are readily obtainable. An early example of this approach is given by Giesing.4 In the case where the airfoil disturbance and the chord-towall clearance ratio are small, analytical results can be obtained directly using the higher-order thin airfoil theory of Van Dyke.5 For a wide range of the chord-to-wall clearance ratio, an approach due to Keldysh and Lavrentiev6 for the corresponding hydrofoil problem is appropriate. Plotkin7'8 used this method, which involves a series expansion in the chord-to-wall clearance (submergence depth) ratio, to study the first-order effects of thickness, angle of attack, and camber. In this paper the effect of the thickness of the airfoil on the lift coefficient will be calculated to the second order in the thickness ratio. Analytical results will be presented for the Joukowski airfoil. The first-order angle-of-attack solution for the flat plate will also be given.

Aerodynamics of Low Reynolds Number Flyers

Abstract: 1. Introduction 2. Fixed, rigid wing aerodynamics 3. Flexible wing aerodynamics 4. Flapping wing aerodynamics.