A nanoscale thermal anemometry probe (NSTAP) has been developed to measure velocity fluctuations at ultra-small scales. The sensing element is a free-standing platinum nanoscale wire, 100 nm× 2 μm× 60 μm, suspended between two currentcarrying contacts and the sensor is an order of magnitude smaller than presently available commercial hot wires. The probe is constructed using standard semiconduc...

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...

Turbulence of a windtunnel flow is stirred using objects that have a fractal structure. The strong turbulent wakes resulting from three such objects which have different fractal dimensions are probed using multiprobe hot-wire anemometry in various configurations. Statistical turbulent quantities are studied within inertial and dissipative range scales in an attempt to relate changes in their se...

Human beings spend most of their lifetime indoors. Monitoring indoor airflow in buildings is a matter of health safety, and energy savings. Regarding health safety it is proven that exposure to aerosol pollution like walls and painting material residues, gasses emitted through cooking and heating with biomass fuel, or agricultural residues can result in aggravated health damages for the occupan...

Time–frequency analysis of the dynamics of different wake vorticity structures, generated from a triangular prism orientated with its apex edge against the incoming wind, is carried out. Time–frequency analysis of time-series obtained with hot-wire anemometry is performed through a procedure based on proper orthogonal decomposition and spectral components are extracted with a technique that pro...

Development of a low-cost computer-based system for multi-point measurement of velocity and temperature has been completed. The principle is based on hot-wire anemometry. A typical probe consists of a cold thermistor for flow temperature detection and a hot thermistor for flow velocity detection. The later is selfheated by a thermal potentiometer circuit. The change in resistance of the thermis...

The neutrally stable atmospheric surface layer is used as a physical model of a very high Reynolds number, canonical turbulent boundary layer. Challenges and limitations with this model are addressed in detail, including the inherent thermal stratification, surface roughness and non-stationarity of the atmosphere. Concurrent hot-wire and sonic anemometry data acquired in Utah's western desert p...