Characteristics of a hot-wire microsensor for time-dependent wall shear stress measurements
2003 (English)In: Experiments in Fluids, ISSN 0723-4864, E-ISSN 1432-1114, Vol. 35, no 3, 240-251 p.Article in journal (Refereed) Published
Hot-wire microsensors for the purpose of measuring the instantaneous velocity gradient close to a wall were designed and their characteristics were evaluated. The sensors were made using MEMS (microelectromechanical systems) technology, which permits the fabrication of various microgeometrical configurations with high precision and good repeatability. The design is based on estimates of the heat rates from the sensor wire to the air, through the supports, and to the wall. Several hot-wire configurations were fabricated with wires positioned in the range 50-250 mum from the wall. Requirements for the design and details of the fabrication methodology are outlined. The hot-wire microsensors were calibrated and tested in a flat-plate boundary layer with and without pressure gradients and were found to have good steady-state characteristics. In addition, the developed sensors were used for preliminary studies of transitional phenomena and turbulence, and the sensors were found to have a good time-dependent response as well.
Place, publisher, year, edition, pages
2003. Vol. 35, no 3, 240-251 p.
dynamic-response, viscous sublayer, skin-friction, voltage-perturbation, spatial-resolution, film probes, anemometer, flow, velocity, turbulence
IdentifiersURN: urn:nbn:se:kth:diva-22831DOI: 10.1007/s00348-003-0624-yISI: 000185458500003OAI: oai:DiVA.org:kth-22831DiVA: diva2:341529
QC 201005252010-08-102010-08-102010-10-19Bibliographically approved