Application-Based Learning Of Signal Analysis Methods With The Help Of A Graphical Open-Source Software

In almost all engineering disciplines, engineers need to evaluate and extract information from time-dependent quantities, making signal processing and analysis a central topic in engineering education. The theoretical foundation is anchored in many courses, however, often only few application-based learning opportunities are offered. To provide these opportunities without the need for expensive hardware, a graphical open-source software is developed. This workshop offers a first opportunity to explore how a graphical software can be used to learn signal processing and analysis methods

Measurement procedure for acoustic absorption and bulk viscosity of liquids

A measurement procedure using a modified two-chamber pulse-echo experimental setup is presented, enabling acoustic absorption and bulk viscosity (volume viscosity) measurements in liquids up to high temperature and pressure. Acoustic absorption measurements are particularly challenging, since other dissipative effects, such as diffraction at the acoustic source and at acoustic reflectors, are typically superimposed to the measurement effect. Acoustic field simulations are performed, allowing to investigate acoustic wave propagation qualitatively. The absorption coefficient is determined by evaluating the signal spectrum’s raw moments and applying a method to identify and correct systematic measurement deviations. Measurement uncertainties are estimated by a Monte Carlo method. In order to validate the present measurement procedure, the acoustic absorption in liquid methanol, n-hexane, n-octane, and n-decane is determined experimentally and compared to literature data. The measurement results for methanol are additionally validated by comparison to bulk viscosity data sampled with molecular dynamics simulation