Interaction, Bursting and Dynamic Control of Vortices of a Cropped Double-delta Wing at High Angle of Attack

Interaction, Bursting and Dynamic Control of Vortices of a Cropped Double-delta Wing at High Angle of Attack
Author: Abdullah M. Alkhozam
Publisher:
Total Pages: 217
Release: 1994
Genre:
ISBN:

A flow visualization study of the vortical flow over a cropped double-delta wing model with sharp leading edges and its three derivatives with small geometric modifications (fillets) at the strake wing junction was conducted in the Naval Postgraduate School water tunnel using the dye-injection technique. The fillets increased the wing area of the baseline model by 1%. The main focus of this study was to evaluate the effect of fillets on vortex core trajectories, interactions and breakdown on the leeward surface at high angle of attack (AOA) with zero sideslip angle. Comparison of test results for different fillet shapes indicates delay in both vortex interaction and breakdown at high AOA, particularly for the diamond fillet shapes. The vortex breakdown data implies lift augmentation for both static and dynamic case, with the static data correlating well with recently published numerical data. High angle-of-attack aerodynamics, Effect of fillets on vortex core trajectories, Interaction and breakdown, Flow visualization by dye-injection technique, Static and dynamic water tunnel studies on double-delta wings.

Interaction, Bursting and Control of Vortices of A Cropped Double-Delta Wing at High Angle of Attac

Interaction, Bursting and Control of Vortices of A Cropped Double-Delta Wing at High Angle of Attac
Author:
Publisher:
Total Pages: 224
Release: 1994
Genre:
ISBN:

A flow visualization study of the vortical flow over a cropped double-delta wing model with sharp leading edges and its three derivatives with small geometric modifications (fillets) at the strake wing junction was conducted in the Naval Postgraduate School water tunnel using the dye-injection technique. The fillets increased the wing area of the baseline model by 1%. The main focus of this study was to evaluate the effect of fillets on vortex core trajectories, interactions and breakdown on the leeward surface at high angle of attack (AOA) with zero sideslip angle. Comparison of test results for different fillet shapes indicates delay in both vortex interaction and breakdown at high AOA, particularly for the diamond fillet shapes. The vortex breakdown data implies lift augmentation for both static and dynamic case, with the static data correlating well with recently published numerical data. High angle-of-attack aerodynamics, Effect of fillets on vortex core trajectories, Interaction and breakdown, Flow visualization by dye-injection technique, Static and dynamic water tunnel studies on double-delta wings.

Flight Stability and Automatic Control

Flight Stability and Automatic Control
Author: Robert C. Nelson
Publisher: WCB/McGraw-Hill
Total Pages: 441
Release: 1998
Genre: Aerodynamique / Aeronautique / Aerospatial / Automatique / Avion / Commande / Conception / Controle / Navigation / Stabilite
ISBN: 9780071158381

The second edition of Flight Stability and Automatic Control presents an organized introduction to the useful and relevant topics necessary for a flight stability and controls course. Not only is this text presented at the appropriate mathematical level, it also features standard terminology and nomenclature, along with expanded coverage of classical control theory, autopilot designs, and modern control theory. Through the use of extensive examples, problems, and historical notes, author Robert Nelson develops a concise and vital text for aircraft flight stability and control or flight dynamics courses.

Computational Fluid Dynamics Investigation of Vortex Breakdown for a Delta Wing at High Angle of Attack

Computational Fluid Dynamics Investigation of Vortex Breakdown for a Delta Wing at High Angle of Attack
Author: Jacob A. Freeman
Publisher:
Total Pages: 172
Release: 2003-03-01
Genre: Delta wing airplanes
ISBN: 9781423504412

Using the commercially available FLUENT 3-D flow field solver, this research effort investigated vortex breakdown over a delta wing at high angle of attack (a) in preparation for investigation of active control of vortex breakdown using steady, along- core blowing A flat delta-shaped half-wing with sharp leading edge and sweep angle of 600 was modeled at a 180 in a wind tunnel at Mach 0,04 and Reynolds number of 3,4 x 10(sub 5). A hybrid (combination of structured and unstructured) numerical mesh was generated to accommodate blowing ports on the wing surface. Results for cases without and with along-core blowing included comparison of various turbulence models for predicting both flow field physics and quantitative flow characteristics, FLUENT turbulence models included Spalart-Allmaras (S-A), Renormalization Group k-e, Reynolds Stress (RSM), and Large Eddy Simulation (LES), as well as comparison with laminar and inviscid models. Mesh independence was also investigated, and solutions were compared with experimentally determined results and theoretical prediction, These research results show that, excepting the LES model for which the computational mesh was insufficiently refined and which was not extensively investigated, none of the turbulence models above, as implemented with the given numerical grid, generated a solution which was suitably comparable to the experimental data. Much more work is required to find a suitable combination of numerical grid and turbulence model.