Turbulence enhances insects' life?

Invasive insect species such as mosquitos and moths are a major menace that draw billions of dollars in prevention and healthcare, in addition to causing nearly a million deaths each year. Host-seeking behavior – where mosquitos approach humans using air-borne odor cues from even 50 meters away – remains unexplored with insects employing robust tracking strategies, apparently leveraging the flow turbulence instead of resisting it. Understanding this could yield not only efficient insect control strategies but also robust bio-inspired algorithms for bio-chemical hazard tracking.

Making energy-efficient vehicles quieter

Designing energy-efficient vehicles to tackle climate change is an urgent challenge but it turns out that energy efficiency and aerodynamic noise are inversely related to each other. Noise is detrimental to human health and often constrains  aerodynamic efficiency through public policy. Extensive investigation of the canonical flat plate boundary layer and pipe flow has yielded well-accepted tools to predict drag penalty, structural vibrations, and noise. However, practical applications suffer from complicated boundary conditions and very high Reynolds numbers. Experiments that use cutting-edge techniques to investigate complex flows (with roughness, flexible surfaces, wall curvature etc.) are critical as they remain as the only feasible approach for high Reynolds number regime. 

Informing climate modelling and predictions

The recent AR6 Climate Change 2021 report by the Intergovernmental Panel on Climate Change (IPCC) highlights the state of the art in weather and climate predictions that rely on very high-resolution (< 200 m) simulations. However, it also highlights the handicaps to generating highly reliable projections of sea level rise, precipitation patterns, air pollution, and surface temperature. One of the key limitations is the paucity of near-surface planetary boundary layer physics where recent studies have shown Monin-Obukhov Stability Theory (MOST) to breakdown. To combat this, we need comprehensive data for accurate sub-grid scale models, through extensive field campaigns to document the boundary layer characteristics in the bottom fifty meters of the planetary boundary layer. We aim to deliver this by implementing a cost-effective, large scale, bubble tracking velocimetry technique over a broad range of flow conditions.

Pixelated Flow facilities for tomorrow's fluid dynamics

Most incompressible wind tunnels are designed to generate flow at a range of speeds and have been optimized for some or all of mild spatio-temporal variability, large-scale unsteadiness, low background noise, full dynamic similarity. However, current technological challenges in fluid dynamics, such as with urban air mobility, are increasingly complex with vehicles subjected to atmospheric turbulence, vehicle wakes, three-dimensional building vortices, thermal updrafts -- all simultaneously. To enable controlled studies that reproduce the critical physics of such flows we need a fundamentally new concept, like the recently proposed distributed flow facility made of computer cooling fans. Working with our collaborators at the U  We are proposing such a facility using a solid-state nozzle that has no moving parts and can generate stable flow-speeds up to 10 m/s.

 

Archived Projects

Quantitative Visualization of Atmospheric Flows

A novel sensor for large scale turbulent pressure

Space-time structure of turbulent inflow to a rotor

Microphone sensitivity to wall shear stress