Development of LIF based tomography technique for studying turbulent shear flows

Abstract

Clouds are one of the major sources of uncertainty in climate prediction (IPCC Fourth Assessment Report: Climate Change 2007). They play a significant role in transporting heat across the whole extent of the troposphere. Cloud formation and its development is a complex phenomenon, because of which until recently no effective laboratory studies were done on clouds, because there was no technique or apparatus that could handle those complexities (Stratmann et al., 2009). Narasimha et al. (2011) were able to successfully reproduce a variety of cloud forms occurring in nature. They presented “the transient plume subjected to off-source diabatic heating” as an appropriate model for simulating cloud flows. Taking lead from there, we planned to study the entrainment characteristics of orographic clouds in laboratory. We modeled orographic clouds as diabatic, planar turbulent, wall-jets. Validation of such a model would be easier in the field compared to free standing clouds, as instruments can be placed along the terrain to measure the actual flow conditions. Also, the two dimensionality of the planar wall jet makes it closer analogue to an orographic cloud as they rise as a layer hugging along the mountain slope. We subject this wall jet to volumetric hea