We present a new approach to Computational Fluid Dynamics CFD using adaptive stabilized Galerkin finite element methods with duality based a posteriori error control for chosen output quantities of interest. We address the basic question of computability in CFD: For a given flow, what quantity is computable to what tolerance to what cost? We focus on incompressible Newtonian flow with medium to...

This paper presents the implementation of a modified state observer-based adaptive dynamic inverse controller for the Black Kite micro aerial vehicle. The pitch and velocity adaptations are computed by the modified state observer in the presence of turbulence to simulate atmospheric conditions. This state observer uses the estimation error to generate the adaptations and, hence, is more robust ...

[1] Quantifying diapycnal mixing in stably stratified turbulence is fundamental to the understanding and modeling of geophysical flows. Data of diapycnal mixing from direct numerical simulations of homogeneous stratified turbulence and from grid turbulence experiments, are analyzed to investigate the scaling of the diapycnal diffusivity. In these homogeneous flows the instantaneous diapycnal di...

A non-hydrostatic code that numerically solves the unsteady, three-dimensional, primitive equations is used. Advanced models such as the dynamic mixed model and the dynamic eddy viscosity model are utilized to represent subgrid processes in the LES approach. A novel near-wall model has been developed so as to increase the Reynolds number of boundary flows to realistically large geophysical valu...

This course material is used in two courses in the International Master’s programmeAppliedMechanics at Chalmers. The two courses are TME225 Mechanics of fluids (Chapters 1-10), and MTF270 Turbulence Modeling (Chapters 11-27). MSc students who follow these courses are supposed to have taken one basic course in fluid mechanics. The lecture notes are also used in the three-day course Unsteady Simu...

In this Letter we have analyzed the temporal correlations of the angle-of-arrival fluctuations of stellar images. Experimentally measured data were carefully examined by implementing multifractal detrended fluctuation analysis. This algorithm is able to discriminate the presence of fractal and multifractal structures in recorded time sequences. We have confirmed that turbulence-degraded stellar...

We discuss tools for calculating divergence-free fields for artistic particle simulations. We introduce a simple, fast divergence-free noise function which can be used for turbulence. We also describe how the interpolation technique used by the noise function can be used for calculating artist-controlled divergence-free fields. The artist can create realistic unbounded flow fields without the c...

This paper presents a numerical solution for a changing combustor geometry. The effects of the geometric change on the main parameters of the chamber are considered. For this purpose the original geometry and the new one are simulated numerically by a 3-D CFD code and the results are compared. Finally, comments are presented regarding this change. A model is used for turbulence modeling and a...

This paper presents a numerical solution for a changing combustor geometry. The effects of the geometric change on the main parameters of the chamber are considered. For this purpose the original geometry and the new one are simulated numerically by a 3-D CFD code and the results are compared. Finally, comments are presented regarding this change. A model is used for turbulence modeling and a...