Skip to main content

WPI ME Graduate Seminar Series 2021-2022 - From Silent Flight of Owls to Buzzing Mosquitoes by Dr. Rozhin Hajian

January 26, 2022

WPI ME Graduate Seminar Series 2021-2022

From Silent Flight of Owls to Buzzing Mosquitoes

Rozhin Hajian 

Postdoctoral Associate

Department of Applied Mathematics

Harvard University

10:00-10:50 am, Wednesday, Jan. 26 Zoom Link: 

Natural fliers flap their wings to fly, generating sound due to the scattering of turbulence at the trailing edge. However, many owl species are believed to fly silently as a result of their unique plumage, which includes a porous wing planform and trailing edge. The identification of physical mechanisms by which an owl achieves this noise reduction may have significant application to the development of quieter airframes and wind turbines where edge noise is prominent. However, such noise reduction strategies involving porosity are likely to have a detrimental effect on the aerodynamic performance, where a rapid means to assess generalized porosity distributions is lacking. The first part of this talk will focus on the development and formulation of mathematical fluid dynamics models for silent owl flight, with a concentration on the effects of wing porosity and its potential aerodynamic performance trade-off with acoustic stealth. 


Despite owls, mosquitoes generate flapping sounds and utilize them for mating purposes, as the sound generated by the wingbeat is usually different for males and females of the same species. Researchers have taken advantage of the flapping sounds of natural fliers for numerous purposes, including the design of quiet drones. Possibly, one of the most significant applications of flight tone detection is to identify disease-carrying insects using their noise footprints, which can be used to build an early warning system to prevent mosquito-borne diseases. In order to fulfill this goal, deep learning algorithms are applied to classify mosquitoes utilizing the data of their wingbeat sounds.

About the Speaker

Dr. Rozhin Hajian is currently a "Future Faculty Fellow" at Northeastern University and an associate at Harvard University. In 2018, she joined the School of Engineering and Applied Sciences at Harvard University, with the group of Prof. Michael P. Brenner, as a Postdoctoral Associate. She was also a lecturer at Northeastern University, teaching "Fluid Mechanics," ME3475, in Fall 2019 & Spring 2020. 

Dr. Hajian was awarded the 2019 "David Crighton fellowship" from the Department of Applied Mathematics and Theoretical Physics (DAMTP), University of Cambridge, UK. She spent summer 2019 in Cambridge, UK, visiting Prof. Lorna Ayton. Before joining Harvard, she completed her undergraduate degree in Chemical engineering from Sharif University of Technology (SUT), Tehran, Iran, in 2011. During her time at Sharif, she was selected as the first female student from Iran to participate in the Young Scientist Exchange Program (YSEP) at Tokyo Institute of Technology, Japan, from 2009 to 2010. Later, she was a graduate fellow at Lehigh University (Bethlehem, PA) where she earned her master's degree in Mechanical Engineering, specialized in control systems, in 2014 under the supervision of Prof. Nader Motee. She has also received her Ph.D. in the Department of Mechanical Engineering and Mechanics at Lehigh University, under the supervision of Prof. Justin Jaworski. 

Dr. Hajian has received a number of awards during her graduate studies, including the "Graduate Student Life Leadership Award" in 2016. She was further honored for her research merit and leadership activities with the 2018 "Graduate Student Merit Award."