Maxwell's demon and quantum-dot cellular automataPower gain and dissipation in quantum-dot cellular automataWe consider Clifford quantum cellular automata ͑CQCAs͒ and their time-evolution. CQCAs are an especially simple type of quantum cellular automata, yet they show complex asymptotics and can even be a basic ingredient for universal quantum computation. In this work we study the time evolution of different classes of CQ-CAs. We distinguish between periodic CQCAs, fractal CQCAs, and CQCAs with gliders. We then identify invariant states and study convergence properties of classes of states, such as quasifree and stabilizer states. Finally, we consider the generation of entanglement analytically and numerically for stabilizer and quasifree states.

This paper gives an overview about prediction capabilities and the development of noise reduction technologies appropriate to reduce high lift noise and propeller noise radiation for future low noise transport aircraft with short takeoff and landing capabilities. The work is embedded in the collaborative research centre SFB 880 in Braunschweig, Germany. Results are presented from all the acoustics related projects of SFB 880 which cover the aeroacoustic simulation of the effect of flow permeable materials, the characterization, development, manufacturing and operation of (porous) materials especially tailored to aeroacoustics, new propeller arrangements for minimum exterior noise due to acoustic shielding as well as the prediction of vibration excitation of aircraft structures, reduced by porous materials.

In this contribution a numerical study of a turbulent jet flow is presented. The simulation results of two different variants of the Lattice Boltzmann method (LBM) are compared. The first is the well-established D3Q19 MRT model extended by a Smagorinsky Large Eddy Simulation (LES) model. The second is the D3Q27 Factorized Cascaded Lattice Boltzmann (FCLB) model without any additional explicit turbulence model. For this model no studies of turbulent flow with high resolution on nonuniform grids existed so far. The underlying computational procedure uses a time nested refinement technique and a grid with more than a billion DOF. The simulations were conducted with the parallel multi physics solver VIRTUALFLUIDS. It is shown that both models are feasible for the present flow case, but the FCLB outperforms the traditional approach in some aspects.

In diesem Beitrag werden Belüftungseffekte am Beispiel des EnergieForums Berlin untersucht. Um Erkenntnisse über den Einfluss fluktuierender Windfelder auf die Belüftung zu erzielen, wird die Windumströmung und Temperatur im und um das Atriumgebäude mit einer Large Eddy Simulation (LES)‐Modell zeitaufgelöst und räumlich untersucht. Dazu wird das Lattice Boltzmann‐Verfahren mit dem Multi Relaxation Time (MRT)‐Modell auf einem D3Q19‐Gitter verwendet. Das kürzlich entwickelte Eso‐Twist‐Verfahren, das nur einen einzigen Lattice Boltzmann‐Verteilungssatz benötigt, kommt zum Einsatz. Als LES‐Modell wird das Smagorinsky‐Modell verwendet. Zur Temperaturmodellierung dient das HTLB‐Verfahren. Die Simulationen werden CUDA‐basiert auf einer GeForceGTX 580 GPGPU durchgeführt. Anhand der Simulationen wird der Abfall der Tracergaskonzentration über der Zeit sowie der mittlere, durch Temperaturunterschiede und äußeren Wind induzierte Fluss bestimmt.Numerical simulation of building ventilation with a Lattice Boltzmann LES model. In this contribution ventilation effects are studied for the EnergieForum Berlin. To estimate the influence of external wind fields on the ventilation process, wind and temperature fields are simulated with a large eddy simulation (LES) model. With this approach spatially‐and time‐resolved output is generated. The Lattice Boltzmann method is being used on a D3Q19 grid with a multiple relaxation time (MRT) model. The recently developed EsoTwist scheme, which uses only a single set of LB distributions, is employed. The Smagorinsky model serves as the LES model. To model the temperature dynamics, the HTLBE method is used. The simulations are CUDA‐based and carried out on a GeForce GTX580 GPGPU. The decay of the tracer‐gas concentration over time and the mean flow through the building generated by temperature gradients and external wind is determined.

No abstract