Sweeps and ejections in ZPG and strong APG turbulent boundary layers

Abstract eng:
We analyse the properties of three-dimensional sweeps and ejections in two zones of a zero-pressure-gradient turbulent boundary layer (ZPG TBL), corresponding to two ranges of Reynolds number, and three zones of a strongly decelerated TBL, corresponding to three ranges of mean velocity defect. In the case of the APG TBL, the last zone includes a very thin separation bubble. The ZPG TBL results show that the properties of sweeps and ejections are only minimally affected by the Reynolds number for the Reynolds number range considered. The effect of increasing mean velocity defect in the adverse pressure gradient (APG) TBL is however significant. The near-wall sweeps and ejections and the taller ones that reach the wall (important in the log layer of the ZPG TBL) become progressively less numerous, less intense and less streamwise elongated. They lose their role as the main contributors to the Reynolds shear stress.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket