Hot-wire anemometry system for studies of mixing in turbulent flows

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****** In both nature and the man-made*world, turbulent flows are the norm, whereas laminar flows are the exception. Fundamental to turbulent flows is their*capacity to rapidly mix mass, momentum or energy – an attribute that underlies*a wide range of processes, including aerodynamics, meteorology, combustion, and*environmental pollutant dispersion. The present proposal requests funding to*refurbish a hot-wire anemometry system, which is the central piece of measurement*equipment in my laboratory, where my research on turbulent mixing is undertaken. A hot-wire anemometer is a state-of-the art*device that measures the velocity of fluid flows with very high spatial and temporal*resolutions, as well providing an unmatched signal-to-noise ratio. It is the tool of choice when one needs to*measure the entire range of scales in turbulent flows, which can exhibit i) length*scales ranging multiples of metres to submillimeter scales, and ii) time scales*spanning ranges from minutes to tenths of milliseconds. *** To continue to make these precise*measurements that are required for my research, two new anemometry channels are*requested to replace the two channels in my system that were purchased nearly*20 years ago, as one has failed and the other is failing. Probes, probe supports, and other accessories*required for proper use of the anemometer are also requested, as these too are*in need of replacement after two decades of use by students working in my*laboratory, under my supervision. *** This requested measurement equipment*will be the workhorse of my research program, which involves a complementary*set of projects relevant to the mixing of scalars (e.g., temperature, chemical*species concentration) in turbulent flows. Specifically, this work involves*four research projects pertaining to: 1) quantification of the effect of*background turbulence on the mixing within free-shear flows, 2) simultaneous*mixing of multiple scalars within turbulent flows, 3) scalar dispersion over a*porous surface/boundary, and 4) effect of turbulent heat transfer above snow*and ice surfaces. The results of this*research will be of immediate relevance to workers in the fields of combustion,*environmental pollutant dispersion, and climate modelling. The research program*will also train HQP in the fields turbulent flows, and thermofluids in general,*supplying skilled professionals to the local aerospace, hydropower, automotive,*etc. industries.