Abstract

Canopies are pervasive in the environment, whether it be forests, crops or clusters of buildings. However, numerous fundamental questions regarding the characteristics of flows inside and over canopies still remain unanswered. Understanding these flows would have applications in energy harvesting, increasing mixing and heat transfer, or even reducing crop losses due to wind damage. In this presentation, we explore if canopy properties can be tuned to exploit the flow over them. First, we will use simple models for flows through canopies to explore the effect of canopy properties on the formation of Kelvin-Helmholtz-like instabilities over them. These models reveal some optimum canopies which result in the formation of strong instabilities. As we increase the sparsity of the canopy, the simplified models fail to capture the flow within it. For this regime, we will present the results obtained from Direct Numerical Simulations of the flow.