Eyi, Sinan
A two-point, aerodynamic design method is presented that improves the aerodynamic performance of transonic airfoils over a range of the flight envelope. It couples an Euler flow solver and a numerical optimization tool. The major limitation of single-point design is the poor off-design performance. Two-point design is used to extend the optimized performance range over more of the desired flight envelope. The method is applied to several transonic flow design points, and the results are compared to single-point design results. The secondary design points are chosen by varying the Mach number and the angle of attack. The two-point designs perform better than the single-point design over the design-point range.


High-lift design optimization using Navier-Stokes equations
Eyi, Sinan; Rogers, SE; Kwak, D (American Institute of Aeronautics and Astronautics (AIAA), 1996-05-01)
This article presents a design optimization method for maximizing lift without increasing the drag of multielement airfoils at takeoff and landing configurations. It uses an incompressible Navier-Stokes dow solver (INS2D), a chimera overlaid grid system (PEGSUS), and a constrained numerical optimizer (DOT). Aerodynamic sensitivity derivatives are obtained using finite differencing. The method is first validated with single-clement airfoil designs and then applied to three-element airfoil designs. Reliable d...
Accurate position control of a flapping-wing robot enabling free-flight flow visualisation in a wind tunnel
Karasek, Matej; Perçin, Mustafa; Cunis, Torbjorn; van Oudheusden, Bas W.; De Wagter, Christophe; Remes, Bart D. W.; de Croon, Guido C. H. E. (SAGE Publications, 2019-10-02)
Flow visualisations are essential to better understand the unsteady aerodynamics of flapping wing flight. The issues inherent to animal experiments, such as poor controllability and unnatural flapping when tethered, can be avoided by using robotic flyers that promise for a more systematic and repeatable methodology. Here, we present a new flapping-wing micro air vehicle (FWMAV)-specific control approach that, by employing an external motion tracking system, achieved autonomous wind tunnel flight with a maxi...
Investigation of rotor wake interactions in helicopters using 3d unsteady free vortex wake methodology
Yemenici, Öznur; Uzol, Oğuz; Department of Aerospace Engineering (2010)
This thesis focuses on developing and examining the capabilities of a new in-house aerodynamic analysis tool, AeroSIM+, and investigating rotor-rotor aerodynamic interactions for two helicopters, one behind the other in forward flight. AeroSIM+ is a 3-D unsteady vortex panel method potential flow solver based on a free vortex wake methodology. Validation of the results with the experimental data is performed using the Caradonna-Tung hovering rotor test case. AeroSIM+ code is improved for forward flight cond...
3-D grain burnback analysis of solid propellant rocket motors: Part 1-ballistic motor tests
Puskulcu, G.; Ulaş, Abdullah (Elsevier BV, 2008-12-01)
The performance prediction of solid rocket motors is an important phase during the design process and it can be achieved easily if the burnback steps of the solid propellant are known. A method was developed by the authors to analyze and determine the grain burnback of solid propellants in rocket motors. To verify the predictions from the model, subscale ballistic rocket motor tests were performed in this study. An existing rocket motor was modified in terms of insulation, ignition delay, and sealing. Compo...
Optimization of Flapping Motion Parameters for Two Airfoils in a Biplane Configuration
Kaya, Mustafa; Tuncer, İsmail Hakkı; Jones, Kevin D.; Platzer, Max F. (American Institute of Aeronautics and Astronautics (AIAA), 2009-03-01)
Flapping motion parameters of airfoils in a biplane configuration are optimized for maximum thrust and/or propulsive efficiency. Unsteady, viscous flowfields over airfoils flapping in a combined plunge and pitch are computed with a parallel flow solver on moving and deforming overset grids. The amplitudes of the sinusoidal pitch and plunge motions and the phase shift between them are optimized for a range of flapping frequencies. A gradient-based optimization algorithm is implemented in a parallel computing...
Citation Formats
J. HAGER, S. Eyi, and K. LEE, “2-POINT TRANSONIC AIRFOIL DESIGN USING OPTIMIZATION FOR IMPROVED OFF-DESIGN PERFORMANCE,” JOURNAL OF AIRCRAFT, pp. 1143–1147, 1994, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/40013.