Turbulent Canopy Flows

Together with the Israel Institute for Biological Research (IIBR), the lab studies turbulence structure inside and above the canopy layer, aiming to understand how pollution spreads in urban and forested areas. The work was led by Dr. Ron Shnapp (Ph.D. 2020) and continues with Lior Shig and Omri Kimhi.

The team developed an extended version of the 3D-PTV method, presented at the Les Houches School on Turbulence, to access the Lagrangian structure of canopy turbulence directly rather than through time-averaged statistics.

A more recent multi-technique campaign, led by Lior Shig, combines Particle Image Velocimetry (PIV) and Laser Doppler Anemometry (LDA) for the velocity field with a Fast Flame Ionization Detector (FFID) for scalar concentration, enabling simultaneous measurement of momentum and scalar transport within and above the canopy layer. The results show that sweep and ejection events produce regions of counter-gradient scalar flux in the roughness sublayer. Omri Kimhi is extending the work to topographically complex terrain.