Management and Control of Unsteady and Turbulent Flows
Abstract
Conclusions from a wide range of experiments in transitioning, turbulent, separated and unsteady flow fields include the following highlights: The simultaneous generation of controlled phase-coupled plane TS waves and oblique waves was used to investigate the development of three dimensional disturbances and mechanisms of transition in a Blasius boundary layer. From these experiments, the detuning of the fundamental/subharmonic resonance emerges as a primary candidate for the transition process under natural conditions. Three dimensional mappings of the Reynolds-stress-producing events in turbulent boundary layers over a range of Reynolds numbers and initial conditions have demonstrated that an integral-size of these dynamical motions scales better with outer variables as compared with inner variables. While the wall or inner layer is responsible for their initial, the hierarchy of their scales in the log layer expands with Reynolds number according to this outer scaling. Real-time reactive control of a model unsteady separating flow was successfully implemented using a simple scheme for the detention of the separation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1991
- Accession Number
- ADA240050
Entities
People
- Candace C. Wark
- Hassan M. Nagib
- Mukund Acharya
- Patrick H. Reisenthel
- Thomas C. Corke
Organizations
- Illinois Institute of Technology