This work provides a three-dimensional energy optimization analysis, looking for perturbations inducing the largest energy growth at a finite time in a boundary-layer flow in the presence of roughness elements. Amplification mechanisms are described which by-pass the asymptotical growth of Tollmien–Schlichting waves. The immersed boundary technique has been coupled with a Lagrangian optimization in a three-dimensional framework. Two types of roughness elements have been studied, characterized by a different height. The results show that even very small roughness elements, inducing only a weak deformation of the base flow, can strongly localize the optimal disturbance. Moreover, the highest value of the energy gain is obtained for a varicose perturbation, pointing out the importance of varicose instabilities for such a flow and a different behavior with respect to the secondary instability theory of boundary layer streaks.
Skip Nav Destination
ASME 2012 Fluids Engineering Division Summer Meeting collocated with the ASME 2012 Heat Transfer Summer Conference and the ASME 2012 10th International Conference on Nanochannels, Microchannels, and Minichannels
July 8–12, 2012
Rio Grande, Puerto Rico, USA
Conference Sponsors:
- Fluids Engineering Division
ISBN:
978-0-7918-4475-5
PROCEEDINGS PAPER
Optimal Perturbations in Boundary Layer Flows Over Rough Surfaces Available to Purchase
S. Cherubini,
S. Cherubini
Politecnico di Bari, Bari, Italy
Search for other works by this author on:
M. D. de Tullio,
M. D. de Tullio
Politecnico di Bari, Bari, Italy
Search for other works by this author on:
G. Pascazio
G. Pascazio
Politecnico di Bari, Bari, Italy
Search for other works by this author on:
S. Cherubini
Politecnico di Bari, Bari, Italy
M. D. de Tullio
Politecnico di Bari, Bari, Italy
P. De Palma
Politecnico di Bari, Bari, Italy
G. Pascazio
Politecnico di Bari, Bari, Italy
Paper No:
FEDSM2012-72219, pp. 1395-1406; 12 pages
Published Online:
July 24, 2013
Citation
Cherubini, S, de Tullio, MD, De Palma, P, & Pascazio, G. "Optimal Perturbations in Boundary Layer Flows Over Rough Surfaces." Proceedings of the ASME 2012 Fluids Engineering Division Summer Meeting collocated with the ASME 2012 Heat Transfer Summer Conference and the ASME 2012 10th International Conference on Nanochannels, Microchannels, and Minichannels. Volume 1: Symposia, Parts A and B. Rio Grande, Puerto Rico, USA. July 8–12, 2012. pp. 1395-1406. ASME. https://doi.org/10.1115/FEDSM2012-72219
Download citation file:
5
Views
Related Proceedings Papers
Related Articles
Measurements of Surface-Roughness Effects on the Development of a Vortex Produced by an Inclined Jet in Cross-Flow
J. Fluids Eng (May,2004)
Effects of Weak Free Stream Nonuniformity on Boundary Layer Transition
J. Fluids Eng (March,2006)
Nonclassical Thermal Effects in Stokes’ Second Problem for Micropolar Fluids
J. Appl. Mech (July,2005)
Related Chapters
Thermal Interface Resistance
Thermal Management of Microelectronic Equipment
On the Evaluation of Thermal and Mechanical Factors in Low-Speed Sliding
Tribology of Mechanical Systems: A Guide to Present and Future Technologies
The Relation between Cold-Work-Induced Microstructural Evolution and the Postannealing Grain Structures in Zircaloy-4
Zirconium in the Nuclear Industry: 20th International Symposium