Computational Investigation of Unsteady Compressible Flow over a Fixed Delta Wing Using Detached Eddy Simulation

Ansarian, H.; Hadidoolabi, M.

doi:10.22060/mej.2017.12863.5455

Computational Investigation of Unsteady Compressible Flow over a Fixed Delta Wing Using Detached Eddy Simulation

Document Type : Research Article

Authors

Malek Ashtar University of Technology, Tehran, Iran

10.22060/mej.2017.12863.5455

Abstract

Unsteady compressible flows over a stationary 60-degree swept delta wing with a sharp
leading edge were computationally simulated at different Mach numbers and moderate angles of the
attack. An unstructured grid, Spalart-Allmaras Detached Eddy Simulation turbulence model, and a
dual-time implicit time integration were used. Vortical flow structures associated with various freestream
conditions are displayed and their variations versus time are studied. Variations of flow field
parameters, such as u velocity component and pressure coefficient with the flow time are demonstrated
at several point probes in the flow field. A Power Spectral Density frequency analysis is performed for
such unsteady behaviours to identify the dominant frequencies which exist in each flow condition. The
frequency analyses show that low frequencies associated with vortex breakdown oscillation are the most
dominant frequencies in all cases where vortex breakdown occurs. Dominant frequencies associated with
helical mode instability are also present at the probes downstream of breakdown. Dominant frequencies
related to the shear layer instabilities were observed for the low subsonic regime.

Highlights

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Keywords

References