로봇, 우주항공, 기계기반기술 분야를 선도하는 글로벌 미래 인재 양성
기계로봇공학과Phononic Subsurfaces: Phonon Engineering by Crystals or Metamaterials for Flow Control
Professor Mahmoud I. Hussein
University of Colorado Boulder
2025-06-16 (Mon)10:30-11:30
Room 114
Abstract:Flow control is a longstanding challenge in fluid dynamics, with significant implications for efficiency in aerodynamics, energy systems, and transportation. Traditional approaches—whether passive or active—seek to manipulate flow instabilities to delay transition to turbulence or promote mixing. In this seminar, Prof. Mahmoud I. Hussein introduces a novel paradigm: phononic subsurfaces (PSubs). These are finite phononic materials—such as crystals or elastic metamaterials—embedded beneath a flow-exposed surface, designed to manipulate mechanical vibrations (phonons) that couple with the overlying flow field. By carefully engineering the band structure and truncation characteristics of these materials, PSubs enable phase-synchronized interactions with the fluid, allowing for passive but highly tunable control over flow instabilities. Prof. Hussein will present both the theoretical foundations and the latest developments, including a lattice of PSubs designed to delay laminar-to-turbulent transition. This talk highlights an emerging intersection of phononics and fluid mechanics with promising implications for next-generation flow control technologies.
Bio:Prof. Hussein is the Alvah and Harriet Hovlid Professor in the Department of Aerospace Engineering Sciences at the University of Colorado Boulder, with a courtesy appointment in Physics. His research focuses on the dynamics of phononic materials and metamaterials, with applications in vibration control, heat transport, and flow control. He has received the DARPA Young Faculty Award and the NSF CAREER Award, and currently leads major projects on nanophononic metamaterials and phononic subsurfaces. He is a Fellow of ASME, founding Vice President of the International Phononics Society, and co-founder of the Phononics 20xx conference series.
Host : ProfessorSolkeun Jee