We adapt the formalism of the statistical theory of 2D turbulence in the case where the Casimir constraints are replaced by the specification of a prior vorticity distribution. A new relaxation equation is obtained for the evolution of the coarse-grained vorticity. It can be used as a thermodynamical parametrization of forced 2D turbulence (determined by the prior), or as a numerical algorithm ...

Two axisymmetric shock-wave / boundary-layer interaction (SWBLI) cases are used to benchmark oneand two-equation Reynolds-averaged Navier-Stokes (RANS) turbulence models. This validation exercise was executed in the philosophy of the NASA Turbulence Modeling Resource and the AIAA Turbulence Model Benchmarking Working Group. Both SWBLI cases are from the experiments of Kussoy and Horstman for ax...

– The response of turbulent flow to time-modulated forcing is studied by direct numerical simulations of the Navier-Stokes equations. The large-scale forcing is modulated via periodic energy input variations at frequency ω. The response is maximal for frequencies in the range of the inverse of the large eddy turnover time, confirming the mean-field predictions of von der Heydt, Grossmann and Lo...

intake system design as well as inlet ports and valves configuration is of paramount importance in the optimal performance of internal combustion engines. in the present study, the effect of inlet ports design is investigated on om-457la diesel engine by using a cfd analysis and the avl-fire code as well. a thermodynamic model of the whole engine equipped with a turbocharger and an intercooler ...

We introduce a machine model for the execution of strategies in (regular) infinite games that refines the standard model of Mealy automata. This model of controllers is formalized in the terminological framework of Turing machines. We show how polynomially sized controllers can be found for Muller and Streett games. We are able to distinguish aspects of executing strategies (”size”, ”latency”, ...

UNLABELLED Accurate prediction of ventilation flow is of primary importance for designing a healthy, comfortable, and energy-efficient indoor environment. Since the 1970s, the use of computational fluid dynamics (CFD) has increased tremendously, and nowadays, it is one of the primary methods to assess ventilation flow in buildings. The most commonly used numerical approach consists of solving t...

The effect of the Hall term on the evolution of the magnetorotational instability (MRI) in weakly ionized accretion disks is investigated using local axisymmetric simulations. First, we show that the Hall term has important effects on the MRI when the temperature and density in the disk is below a few thousand K and between 1013 and 1018 cm−3 respectively. Such conditions can occur in the quies...

This work presents results of flow simulations performed with the commercial code CFX 11.0 in a PWR 5x5 rod bundle segment with a split vane spacer grid. The geometrical configuration and flow conditions used in the experimental studies performed by Karoutas were assumed in the simulations. To make the simulation possible with a limited computational capacity and acceptable mesh refinement, the...