Experimental analysis of different systems are conducted. Numerical methods and software packages are developed.
A single bubble is levitated in a a water filled cavity with the help of ultra sound. Above a critical sound intensity the bubble starts to emit light pulses of ultra short pulse length. Shock waves are radiated into the fluid. The temperature in the bubble exceeds 20,000 K thus igniting chemical and plasma physical processes in the bubble. Highly nonlinear oscillations are seen together with chemical, diffusional and mechanical instabilities (more ...).
Software for the analysis of time series is developed. New methods from the theory of nonlinear dynamical systems and information theory are developed and coded.
The NLyzer is a software package for the nonlinear analysis of dynamical systems. In a user friendly graphical interface several nonlinear methods can be combined and used for system analysis in real time.
Ultra sound of high intensity is focused in water. Millions of tiny bubbles appear in the liquid, arranging to form a moving dentritic structure. The bubbles oscillate nonlinearly and radiate sound. The radiated sound spectrum may show harmonic and subharmonic frequencies and also be broadband chaotic. Also light emissions are detected that are generated by the adiabatic compression of the bubbles. (more ...).
With the help of a standing wave of ultra sound frequency milli meter sized fluid drops are levitated. With the help of modulations or parametrical processes nonlinear oscillations of the drops are induced (more ...).
Dr. Joachim Holzfuss
Nichtlineare Physik
Institut für Angewandte Physik
Fachbereich 05 - Physik
Technische Universität Darmstadt
Schlossgartenstr. 7
D-64289 Darmstadt
+49 6151 16-2884
+49 6151 16-4534
Joachim.Holzfuss@physik.tu-...