Office of Naval Research Names Perry Johnson a Young Investigator
Nov. 18, 2024 - The Office of Naval Research has selected Perry Johnson, assistant professor of mechanical and aerospace engineering, for a Young Investigator Program (YIP) grant. He is among 24 outstanding early career academics to receive the award this year and will receive $750,000 for his research exploring ways to efficiently leverage high-performance computing for predicting air or fluid flows over immersed objects like airplanes or submarines.
Developing accurate, robust approximations for turbulence is notoriously difficult. One of the most promising techniques is large-eddy simulation (LES). Johnson’s research group is developing a new framework for LES that overcomes some of the shortcomings of existing approaches.
Given the relatively low viscosities of air and water compared to the size and speed of large vehicles, very thin boundary layers form within the fluid (water or air) directly adjacent to the outer skin of the vehicle. Within these boundary layers, rapid spatial variation of the flow's velocity triggers instabilities, and the flow transitions from a smooth, laminar state to a chaotic turbulent state characterized by even more rapid, smaller-scale fluctuations. The resulting turbulence within the boundary layer generates a chaotic soup of microvortices.
Johnson says that directly applying the fundamental laws of fluid mechanics on these flows is often out of reach even for the most powerful supercomputers in the world, so it is vital for scientists and engineers to develop approximation methods to make such supercomputer calculations feasible.
Johnson says he has been making progress with support from the National Science Foundation on tackling some LES modeling difficulties related to flows away from solid surfaces. “This new grant will enable us to dramatically expand our efforts, especially related to tricky physics of flows over complex surfaces with curvature and roughness.”
The 2025 YIP awardees were chosen from more than 230 applicants. The ONR YIP is a highly competitive program that supports outstanding early-career academics in science, technology, engineering and mathematics who propose innovative solutions to Navy and Marine Corps warfighter challenges.
– Lori Brandt
