Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : October 10, 2020 - October 11, 2020
Pages 0150-
For accurate measurement of fluid temperature fluctuations by a fine-wire temperature sensor (coldwire), it is necessary to keep the sensor length about 1000 times larger than its diameter to avoid the deterioration in temporal response. However, a longer sensor unfortunately reduces its spatial resolution. In the present study, we have tested the performance of fine cold-wires of several different sensor lengths, and examined the effects of the temporal and spatial resolutions on the rms values, power spectra and instantaneous signal traces of temperature fluctuations in a canonical turbulent thermal boundary layer. It is found that applying the response compensation to the outputs of cold-wires with a relatively small length-to-diameter ratio enables us to avoid the deterioration in spatial resolution and to obtain sufficiently accurate measurement results.
