Aerospace Science and Technology
Parisa Ghanooni; Mostafa Kazemi; Mahmoud Mani
Abstract
This study focuses on improving performance of a supercritical wing equipped with winglets at different cant angles. This study aims to experimentally investigate the variation of aerodynamic performance of a supercritical wing of NASA Sc (2)-0410 airfoil at lower Reynolds numbers with winglets at various ...
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This study focuses on improving performance of a supercritical wing equipped with winglets at different cant angles. This study aims to experimentally investigate the variation of aerodynamic performance of a supercritical wing of NASA Sc (2)-0410 airfoil at lower Reynolds numbers with winglets at various cant angles. The tests were performed by measuring the lift and drag force using a three-component balance within a broad range of angle of attack from -4 to 20 degrees and at three different subsonic flow velocities. Results include changes in lift, drag, and aerodynamic performance for each winglet cant angle compared to the baseline wing. The results show that winglets generally increase the lift force and decrease the drag force by decreasing the size and strength of the wingtip vortices. Moreover, the optimal winglet for each case is extracted based on the aerodynamic performance provided by each winglet. In order to better and more accurately compare the effect of different mounting angles of the winglet on the aerodynamic performance of the base wing, the impact of each winglet is shown separately. Accordingly, it is observed that the winglets with angles of 0o and 15 o, namely W0 and W15, have shown good performance in increasing the lift coefficient. Also, the winglet with 90 degrees has shown good performance in creating the least drag force.
Mostafa Kazemi; parisa Ghanoni; Mahdi Sharifi; Mahmood Mani
Abstract
This study focuses on using rotor blade turbine winglets for the purpose of controlling the wingtip vortex in airplanes. The aim of the study is to investigate the effective geometric properties of the rotor blades that are used as winglets, as well as experimental evaluation of their effects on drag, ...
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This study focuses on using rotor blade turbine winglets for the purpose of controlling the wingtip vortex in airplanes. The aim of the study is to investigate the effective geometric properties of the rotor blades that are used as winglets, as well as experimental evaluation of their effects on drag, lift coefficient and the aerodynamic efficiency ratio of the airplane. Seven different types of rotor blades were chosen in regard of their span length, number of blades, and the shape of the blades and experimented in a wind tunnel. The drag and lift force were directly measured via a 3-axis external balance. The position and place of installment of the rotor blades were selected through the studies mentioned in the literature and their geometric properties were further investigated. A finite wing with a NACA641412 cross-sectional airfoil, two similar rotor blades with different span length, two similar rotor blades with different blade count, and three rotor blades with different aerodynamic shapes in terms of installation and twist angle were used as models in this study. All the experiments were conducted at a Reynolds Number of 100,000 and angles of attack ranging from negative 4 to positive 20. The results showed the existence of turbine winglets has increased the lift coefficient and results in a reduction in the drag coefficient. Rotor blades with larger span lengths have increased the aerodynamic efficiency, although they have increased the drag coefficient as well. The number of the blades has had different effect in different angles of attack. The results indicate that rotor blades with acceptable aerodynamic properties can increase the value of aerodynamic efficiency almost twice its base value and delay the wing stall up to the attack angles above 20 degrees.