Effect of Thickness-to-Chord Ratio on Flow Structure of a Low Swept Delta Wing

2018-12-01
Gulsacan, Burak
Sencan, Gizem
Yavuz, Mehmet Metin
The effect of thickness-to-chord (t/C) ratio on flow structure of a delta wing with sweep angle of 35 deg is characterized in a low-speed wind tunnel using laser-illuminated smoke visualization, particle image velocimetry, and surface pressure measurements. Four different t/C ratios varying from 4.75 to 19% are tested at angles of attack, 4, 6, 8, and 10 deg, for Reynolds numbers Re =1 x 10(4) and 3.5 x 10(4). The results indicate that the effect of thicknessto-chord ratio on flow structure is quite substantial, such that, as the wing thickness increases, the flow structure transforms from leading edge vortex to three-dimensional separated flow regime. The wing with lowest t/C ratio of 4.75% has pronounced surface separation at significantly higher angle of attack compared with the wing with highest t/C ratio, which indicates that lowest t/C ratio wing might be more resistive to the stall condition. However, considering the low angles of attack where all wings experience leading edge vortex structure, the strength of the vortex structure increases as the t/C ratio increases, which might suggest a better vortex-induced lift performance with high t/C ratio wing at low angles of attack.
AIAA JOURNAL

Suggestions

Effect of turbulence modeling for the prediction of flow and heat transfer in rotorcraft avionics bay
Akin, Altug; Kahveci, Harika Senem (Elsevier BV, 2019-12-01)
In this paper, four turbulence models are compared on the basis of the predictions they produce for the flow and heat transfer in the avionics bay area of a rotorcraft. The turbulence models studied are the standard k-s, Renormalization Group (RNG) k-epsilon, realizable k-epsilon, and Shear-Stress Transport (SST) k-omega model. The avionics bay used in the study houses avionics equipment mounted on the floor and on a rack inside the bay to mimic a realistic distribution of equipment in actual rotorcraft. Th...
Effects of swirl and high turbulence on a jet in a crossflow
Kavsaoğlu, Mehmet S.; Schetz, Joseph A. (American Institute of Aeronautics and Astronautics (AIAA), 1989-6)
An experimental study has been conducted on the effects of initial swirl and high turbulence in the exhaust of a circular jet injected from a flat plate at a 90-deg angle into a crossflow. The different jet types studied were low-exit turbulence (3%), high-exit turbulence (>10°7o), and 40 and 58% swirl. Surface pressure distributions and mean velocity vector plots were obtained for all of these cases. For the surface pressure distribution tests, the jet to crossflow velocity ratios R were 2.2, 4, and 8 ...
Near-surface topology of unmanned combat air vehicle planform: Reynolds number dependence
Elkhoury, M; Yavuz, Mehmet Metin; Rockwell, D (American Institute of Aeronautics and Astronautics (AIAA), 2005-09-01)
The Reynolds number dependence of the near-surface flow structure and topology on a representative unmanned combat air vehicle planform is characterized using a technique of high-image-density particle image velocimetry, to complement classical dye visualization. Patterns of streamline topology, including bifurcation lines, as well as contours of streamwise and transverse velocity, surface-normal vorticity, and Reynolds stress correlation, all immediately adjacent to the surface of the planform, provide qua...
Near-surface topology and flow structure on a delta wing
Yavuz, Mehmet Metin; Rockwell, D (American Institute of Aeronautics and Astronautics (AIAA), 2004-02-01)
The streamlines, and the corresponding patterns of velocity and vorticity, are characterized on a plane immediately adjacent to the surface of a delta wing using a laser-based technique of high-image-density particle image velocimetry. This technique provides the sequence of instantaneous states, as well as the corresponding time-averaged state, of the near-surface streamline topology and the associated critical points. These topological features are interpreted in terms of patterns of averaged and unsteady...
Computational study of subsonic flow over a delta canard-wing-body configuration
Tuncer, İsmail Hakkı (American Institute of Aeronautics and Astronautics (AIAA), 1998-07-01)
Subsonic flowfields over a close-coupled, delta canard-wing-body configuration at angles of attack of 20, 24,2, and 30 deg are computed using the OVERFLOW Navier-Stokes solver Computed flowfields are presented in terms of particle traces, surface streamlines, and leeward-side surface pressure distributions for the canard-on and -off configurations. The interaction between the canard and the wing vortices, wing vortex breakdown, and the influence of the canard on vortex breakdown are identified, The comparis...
Citation Formats
B. Gulsacan, G. Sencan, and M. M. Yavuz, “Effect of Thickness-to-Chord Ratio on Flow Structure of a Low Swept Delta Wing,” AIAA JOURNAL, pp. 4657–4668, 2018, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/38143.