Turbulence statistics of natural airflow within a large Open Top Chamber

Abstract

The turbulence statistics parameters (variables) of natural airflow within a large Open Top Chamber (OTC), 4 m in high height and 3 m in diameter, were measured with a three-dimensional ultrasonic anemometer/thermometer at Research Station of Changbai Mountain Forest Ecosystems Jilin Province, China in May 2004, for improving the field application of OTP. Results showed that because of the physical limitation, turbulence within OTC exhibited unique map compared with that of natural environments. There were clear daily patterns for most parameters. Turbulence here seemed to be isotropic and closely linked at all directions. Shape of eddies looked like a ’cylinder‘ which was very similar to the shape of OTC. Continuous airflow was always interpreted by large scale eddies from top of OTC and showed high interactive intermittence at all directions.

Keywords

Open top chamber / Turbulence density / Time and length scales / Intermittence / Buoyancy / S716.4 / A

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