Stephan Barth

Laser-cantilever anemometer: A new high-resolution sensor for air and liquid flows

In this article, we present a technical description of a new type of anemometer for gas and especially liquid flows with high temporal and spatial resolution. The principle of the measurement is based on the atomic force microscope technique where microstructured cantilevers are used to detect extreme small forces. We demonstrate the working principle and the design of the sensor, as well as calibration measurements and initial measurements of turbulent flows, which were performed in air and water flows.

Fat Tail Statistics and Beyond

Based on data from three different systems, namely, turbulence, financial market and surface roughness we discuss methods to analyze their complexities. Scaling analysis and fat tail statistics in the context of Levy distributions are compared with a stochastic method, for which a Fokker-Planck equation can be estimated from data. We show that the last method provides a more detailed characterization of complexity.

Alternative high resolution sensor to hot‐wire and hot‐film anemometer

We present a new type of high resolution sensor for turbulent flow measurements based on the optical detection of a deflected cantilever. The Laser-Cantilever-Anemometer (LCA) can be used in air as well as in water without any changes in setup. Experiments for testing the functionality of this sensor in turbulent air flows show that the measured data with the LCA match the data obtained with a hot-wire anemometer up to several kHz.