Optimization method for maximal drag airfoils in the case of nonlinear problems in hydro–aerodynamics
by
Adrian Postelnicu
Dept. of Fluid Mechanics and Thermal Engineering, Transilvania University, Bdul Eroilor, No 29, Brasov, 500036,ROMANIA
Coauthors: Mircea Lupu (Dept. of Mathematics-Informatics, Iuliu Maniu Street, 50, Transilvania University, Brasov, ROMANIA)

In the paper there are solved direct and inverse boundary problems and analytical solution are obtained for optimization problems in the case of some nonlinear integral operators.

We consider the plane potential flow of an inviscid, incompressible and limited or unlimited fluid jet, which encounters a symmetrical airfoil.

Working in the auxiliary canonical half–plane, a singular equation is obtained. Next, the optimization problem is solved in an analytical manner.

The optimal airfoil is designed and then numerical computations concerning aerodynamic parameters (relevant is the drag coefficient) and other geometrical quantities are performed.

Three problems are solved in our contribution: 1. Optimal deflector (in limited flow jets) 2. Optimal deflector–impermeable parachute (in unlimited flow jet - Helmholtz optimal model) 3. Optimal deflector in cavity flows (Jukovski – Roshko – Epler cavity optimal model) The obtained results, both analytically and numerically, are very important in relation with various practical applications, such as thrust reversal devices, direction control of reactive vehicles, jet flaps systems in airplanes wings and turbine blades, or parachutes.

Important results in these topics are reported in the open literature by D. Maklakov (University of Kazan) using the Levi-Civita half-circle, or by Hureau and co-workers (ESEM Laboratory, University of Orleans).

Date received: January 28, 2004

Copyright © 2004 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cakt-38.