(February 25, 2025 12:00) The 74th La Trobe – Kyushu Joint Seminar on Mathematics for Industry
Date：February 25, 2025
Events&SeminarsThe 74th La Trobe – Kyushu Joint Seminar on Mathematics for Industry will be held next week. Details can be found below.
| Title | Linear disturbance development on a rotating disk with time-periodic motion |
| Speaker | Christian Thomas (Macquarie University, Australia) |
| Date & Time | Tuesday, February 25, 12:00 – 13:00 |
| Zoom | https://latrobe.zoom.us/j/85804794906 |
| Abstract | The rotating disk or von Karman boundary layer is the archetypical flow for the study of laminar-turbulent transition processes that occur naturally on the wings of aircraft and is often used to demonstrate laminar flow control applications. This investigation concerns the novel approach of controlling linear disturbance development via a time-periodic modulation of the otherwise steady disk rotation rate. The model is an example of a three-dimensional oscillatory boundary layer that forms by coupling a Stokes layer with the von Karman flow. Results of recent direct numerical simulations are reviewed and illustrate the significant control benefits brought about by disk modulation. Both local and global forms of linear instability are stabilised by the application of time-periodic motion. In the former instance a radial homogeneous flow approximation is modelled whereby the radial dependence of the base flow is ignored. Under this assumption numerical simulations are performed at flow conditions corresponding to convective and absolute instability. For each of these forms of linear instability time-periodic modulation establishes a significant reduction in the spatial and temporal growth rates associated with the disturbance leading to a delay in their onset. Greater control benefits are achieved as the modulation amplitude increases while the stabilising effect is optimised for non-dimensional modulation frequencies near 10. For the genuine radially inhomogeneous base flow comparable control benefits are again realised. |
This seminar is …
This seminar series is a valuable opportunity for graduate students to get acquainted with the work of more experienced researchers in various mathematical fields. Undergraduate students are also welcome to join, as the talks are intended for non-experts, too. Regardless of your area of research, you can attend the seminar to expand your knowledge and get in touch with the latest developments in mathematics for industry.