Modelling turbulence over a step change in roughness

Abstract

This project aims to characterise the evolution of turbulent boundary layers over a step change in roughness by leveraging data assimilation to extract additional information from (incomplete) experimental data. An optimisation problem will be formulated that finds the near-wall flow which is most compatible with available experimental measurements in the logarithmic and outer regions of the flow. The optimised mean profile will be used to devise scaling laws for the local equivalent sand grain roughness and skin friction coefficient behind a step change in roughness. It will also be used as an input to resolvent analysis to predict turbulent spectra and the most energetic velocity fluctuations in the turbulent boundary layer. The amplification properties of these structures, deduced from resolvent analysis, will provide insight on designing passive flow control strategies that can be achieved by varying surface roughness in the streamwise direction.

Document Details

Document Type
DoD Grant Award
Publication Date
Feb 22, 2024
Source ID
FA86552317005

Entities

People

  • Sean Symon

Organizations

  • Air Force Office of Scientific Research
  • United States Air Force
  • University of Southampton

Tags

Fields of Study

  • Physics

Readers

  • Distributed Systems and Data Platform Development
  • Fluid Mechanics and Fluid Dynamics.
  • Theoretical Analysis.