Numerical investigations of rotating cylindrical micro vortex generators for turbulent boundary layer separation control

• Applicant: Professor Dr.-Ing. Ulrich Rist
• Subject Area: Fluid Mechanics
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 455876927

The present application is intended to perform fundamental research on flow control using a new device, called micro Rotating Cylindrical Vortex Generators (mRCVG). Preliminary work has shown that wall-mounted rotating cylinder stubs (with their rotation axis perpendicular to the wall) generate long-lasting streamwise vortices and high-velocity streaks in laminar as well as in turbulent boundary-layer flows. With an according, already verified increase of the skin friction coefficient, it is straightforward to consider mRCVGs as a possible new means for turbulent flow separation control. The present work will try to identify those parameters which yield a maximal mean skin friction downstream of the mRCVGs and then apply these to a test configuration consisting of a turbulent flow over a rounded ramp. Large-Eddy Simulation will be used in order to consider unsteady effects and obtaining insight into the flow dynamics. In the authors’ expectation mRCVGs have the potential to become a simple and presumably robust method which has never been investigated before for separation control in fluid dynamics.

• DFG Programme: Research Grants