Simulations of steady and oscillating flow in diffusers

In this thesis diffuser performance will be simulated with computational fluid dynamics, which will be done with the program Ansys Fluent. The expanding geometry creates an adverse pressure gradient and under certain conditions there will also be separation.<br/><br/>At first a relative simple simulation will be done of a one-directional...

Thermally Driven Sound Source: Application of CNT nanofoams

On chip grown CNT nanofoam has a large surface to volume ratio and excellent thermal electrical properties, which is suitable to be used as a thermoacoustic heater. The highly porous foam exchanges heat with surrounding air efficiently. Every processing step is specifically designed to be CMOS compatible using cleanroom microfabrication. This...

Design, construction and experimental observation of a thermoacoustic prime mover

In this study a thermoacoustic single stage engine configuration is compared to a double stage engine configuration with regard to onset temperature, power density and efficiency. A thermoacoustic prime mover was designed and build using air at 1 atmosphere as a working fluid. The ceramic regenerators were heated using electricity and cooled...

Comparison of multistage thermoacoustic engines in serial versus parallel configurations

In industrial processes about 80% of the energy demand is in the form of heat. One of the problems of the industrial waste heat is the low temperature of this heat. The department of energy efficiency and infrastructure, 'E&I' of the Energy research Center of the Netherlands 'ECN' runs projects in order to use industrial waste heat with a...

Flame front capturing/tracking schemes for compressible and incompressible reactive flow

We present hybrid capturing/tracking methods for the simulation of turbulent premixed flames in meso- and large-scale geometries. Such schemes resemble a tracking schemes in that the flame front is explicitly computed and propagated using a level set method. The flame-flow-coupling uses in-cell-reconstruction. In cut cells, burnt and unburned...