Yazar "Tasci, Mehmet Oguz" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • [ X ]
    Öğe
    Effect of ground on flow characteristics and aerodynamic performance of a non-slender delta wing
    (Elsevier France-Editions Scientifiques Medicales Elsevier, 2021) Tumse, Sergen; Tasci, Mehmet Oguz; Karasu, Ilyas; Sahin, Besir
    The aerodynamic performance and the structure of vortical flow on a delta wing are affected by the influence of the ground in take-off and landing stages. In this context, the effect of the ground on a delta wing having a sweep angle of 40 degrees was investigated by employing Particle Image Velocimetry (PIV), aerodynamic force measuring system and the dye flow visualization technique. Flow characteristics of delta wing were examined under two different angles of attack, alpha = 8 degrees and 11 degrees and variation of the distance between trailing edge of the wing and ground, h normalized with the root chord length, c of the wing. It was observed that the existence of the ground attenuates the magnitude of peak values of primary and secondary vortices due to incomplete development of vortices. The ground effect caused the outboard movement of the leading-edge vortex in a spanwise direction as well as an increase in the size of vortices. Furthermore, the presence of the ground induced a decrease in Strouhal number, St due to the slowing down of vortex formation. Lift and drag coefficient, C-L, and C-D of the delta wing were observed to increase with descending from unbounded flight region into ground effect region. Finally, it was found that C-L/C-D increases by reducing the distance between ground and wing, h/c, and a rise of C-L/C-D is much more effective under the lower angles of attack, alpha. (C) 2020 Elsevier Masson SAS. All rights reserved.
  • [ X ]
    Öğe
    The impact of the pitching motion on the structure of the vortical flow over a slender delta wing under sideslip angle
    (Springer, 2021) Tasci, Mehmet Oguz; Pektas, Mehmet Can; Tumse, Sergen; Karasu, Ilyas; Sahin, Besir; Akilli, Huseyin
    The primary purpose of this investigation is to observe the effect of the pitching motion on the vortical flow structure and bursting of leading-edge vortices over a delta wing under the sideslip angle, beta using a dye visualization technique. In the current work, a delta wing with a sweep angle of ? = 70 degrees was oscillated in upstroke and downstroke direction to be able to discover the influence of pitching motion on the flow characteristics of the delta wing. The values of mean angles of attack were selected as alpha(m) = 25 degrees and alpha(m) = 35 degrees, and the sideslip angle was altered from beta = 0 to 16 degrees. The delta wing oscillated with the various periods of T-e = 5 s, 20 s, and 60 s, respectively. Amplitude of motion was adjusted as alpha(o) = +/- 5 degrees. It is found that the pitching motion of the delta wing under the sideslip angle beta varies the location of the vortex bursting and vortical flow structure substantially.