Nano-scale Hot Wire Sensors for Turbulence Measurement Applications

Hot-wire Array for Turbulence Research in Subgrid-scale Modeling

Modeling of turbulence for Large Eddy Simulations (LES) must be based on sound understanding of the relationships between large and small scales. In order to study flows with a large range of active length-scales, high Reynolds number experimental data can be used. Thermal anemometry provides the possibility of acquiring long records of turbulence data, which are necessary for evaluating statis...

The Influence of Spatial Resolution due to Hot-Wire Sensors on Measurements in Wall-Bounded Turbulence

Reassessment of compiled data reveal that recorded scatter in the hot-wire measured near-wall peak in viscous-scaled streamwise turbulence intensity is due in large part to the simultaneous competing effects of Reynolds number and viscous-scaled wire-length l ( lUτ ν, where l is the wirelength, Uτ is friction velocity and ν is kinematic viscosity). These competing factors can explain much of th...

Spatial resolution correction for hot-wire anemometry in wall turbulence

We investigate spatial resolution issues in hot-wire anemometry measurements of turbulence intensity and energy spectra. Single normal hot-wire measurements are simulated by means of filtering direct numerical simulation (DNS) of turbulent channel flow at Res 1⁄4 934. Through analysis of the two-dimensional energy spectra from the DNS, the attenuation of the small-scale energy levels is documen...

The Hot - wire Anemometer for Turbulence Measurements part III

Mems Flow Sensors for Nano-fluidic Applications

This paper presents micromachined thermal sensors for measuring liquid flow rates in the nanoliter-per-minute range. The sensors use a boron-doped polysilicon thinfilm heater that is embedded in the silicon nitride wall of a microchannel. The boron doping is chosen to increase the heater’s temperature coefficient of resistance within tolerable noise limits, and the microchannel is suspended fro...