
Accession Number : ADP003039
Title : A Geometrically Consistent Linearization Method for an Elliptic Strut,
Corporate Author : BRITISH COLUMBIA UNIV VANCOUVER DEPT OF MECHANICAL ENGINEERING
Personal Author(s) : Calisal,S. M.
Report Date : 17 NOV 1983
Pagination or Media Count : 12
Abstract : Study of irrotational, incompressible flows about thin geometries can be carried out using the wellknown perturbation procedures. In twodimensional flows exact solutions based on mappings can be used to compare the accuracy of firstorder solutions is not sufficiently accurate in representing the pressure and velocity distribution, especially about the leading edge. For threedimensional flows exact solutions are rare and, for more complex problems such as ship wave resistance formulations, an exact solution does not exist but are very difficult to calculate. Therefore, it would appear advantageous to improve firstorder calculations. To this end a perturbation method that incorporates the geometric properties of the disturber is studied. This method is first applied to a symmetric Joukowski airfoil, to an ellipse and an elliptic strut. This method, here called the geometricallyconsistent linearization method, predicts the leading edge pressure variations correctly for the two foils studied and appears to be superior to the classical firstorder solutions. An iterative solution following this procedure further improves the calculation. The method discussed and the following iteration procedure seem to form an efficient numerical solution to airfoil flow problems. The method is then applied to a elliptic strut waveresistant calculation.
Descriptors : *Potential flow, *Incompressible flow, Struts, Perturbations, Two dimensional flow, Ellipses, Numerical methods and procedures, Perturbation theory, Mathematical prediction, Leading edges, Variable pressure, Iterations, Airfoils, Ships, Thinness, Geometric forms, Consistency, Linearity, Canada
Distribution Statement : APPROVED FOR PUBLIC RELEASE