The shear layer structure of a tabbed jet in crossflow

Abstract

Passive devices such as tabs have been shown to be an effective method of altering the characteristics of regular and transverse jets, although the specifics of how tabs affect jet flow fields are not well understood, especially for jets in crossflow. Direct numerical simulations of a tabbed jet in crossflow are performed at a jet Reynolds number of $2000$ at jet-to-crossflow velocity ratios of $R = 2$ and $4$. The simulations use the unstructured overset method developed by Horne & Mahesh [J. Comput. Phys (2019) 397: 108790] to allow for the study of two tab positions with respect to the crossflow direction. The jet structure is shown to vary significantly with the tab placement and $R$, with upstream tabs producing secondary vortices with remarkable similarities to those observed in plane shear layers.

Supported by the Air Force Office of Scientific Research.