Characteristics of Turbulent Airflow Deduced from Rapid Surface Thermal Fluctuations: An Infrared Surface Anemometer

摘要: The intermittent nature of turbulent airflow interacting with the surface is readily observable in fluctuations temperature resulting from thermal imprints eddies sweeping surface. Rapid infrared thermography has recently been used to quantify characteristics near-surface evaporating surfaces. We aim extend this technique by using single-point rapid measurements properties a flow, including exchange processes, view towards development an anemometer. parameters for surface-eddy renewal (\(\alpha \) and \(\beta )\) are inferred on heat plate placed wind tunnel prescribed speeds constant mean temperatures Thermally-deduced agreement values obtained standard three-dimensional ultrasonic anemometer close (e.g., \(\alpha = 3\) 1/26~\hbox {(ms)}^{-1}\) infrared, 1/19~\hbox sonic-anemometer measurements). infrared-based turbulence provide new insights into role buoyancy inherent eddies. link between eddy-spectrum shape parameter window size representing field investigated. results resemble effect sampling height above ground sonic measurements, which enables detection larger higher \). physical basis tests proposed method support potential remote quantification momentum field, as well scalar-flux immediate vicinity