Turbulent wake behind a T-shaped plate: Comparison with a cross-shaped plate

Highlights: • Turbulent wake of a T-shaped plate is studied by DNS. • Similar to a cross-shaped plate the wake is characterized by three qualitatively flow regimes form intersection region to outer branches. • Shear layer instability has been observed. • In contrast to the cross-plate, a main feature of the mean wake structure behind the Tplate is the formation of two symmetrically positioned swirling vortices close to the internal corners of the T. - Abstract: The wake behind T-shaped intersecting flat plates has been studied by direct numerical simulations and compared with the wake behind intersecting plates forming a cross. The Reynolds number based on the uniform inflow velocity and the plate width d was 1000. Similar to the cross-plate the vortex shedding was suppressed in a 4d wide intersection region with a substantial base suction pressure reduction. Shear-layer (K-H) instabilities have been observed and its characteristic frequency obtained. In contrast to the cross-plate, a main feature of the mean wake structure behind the T-plate is the formation of two symmetrically positioned swirling vortices close to the internal corners of the T. This was examined by considering pressure contours and the turbulent production terms of mean streamwise vorticity. In spite of some similarities, major features of the wake behind the T-plate turned out to be distinctly different from the wake behind a cross-plate configuration.