Browsing by Author "Reif, Bjørn Anders Pettersson"
Now showing items 1-20 of 33
-
Anisotropy and shear-layer edge dynamics of statistically unsteady,stratified turbulence
Wingstedt, Emma My Maria; Fossum, Hannibal Eie; Reif, Bjørn Anders Pettersson; Werne, Joseph (2015)Direct numerical simulation data of an evolving Kelvin-Helmholtz instability have been analyzed in order to characterize the dynamic and kinematic response of shear-generated turbulent flow to imposed stable stratification. ... -
Assessment of the dispersion of Legionella-containing aerosols from a biological treatment plant
Blatny, Janet Martha; Tutkun, Murat; Fossum, Hannibal Eie; Skogan, Gunnar; Fykse, Else-Marie; Andreassen, Øyvind; Waagen, Viggo; Reif, Bjørn Anders Pettersson (2011)Legionella was detected in aeration ponds (biological treatment plant) at Borregaard Ind. Ltd., Norway, and in air samples harvested directly above these ponds. Since 2005, three outbreaks of legionellosis occurred within ... -
Computational analysis of shock-induced flow through stationary particle clouds
Osnes, Andreas Nygård; Vartdal, Magnus; Omang, Marianne Gjestvold; Reif, Bjørn Anders Pettersson (2019-03-22)We investigate the shock-induced flow through random particle arrays using particle-resolved Large Eddy Simulations for different incident shock wave Mach numbers, particle volume fractions and particle sizes. We analyze ... -
Computational fluid dynamics simultations of flow and dispersion in the aerosol test chamber
Fossum, Hannibal E.; Reif, Bjørn Anders Pettersson (2012-10-19)This report presents findings from computer simulations of the air flow and the dispersion of aerosols inside a rectangular 12 m3 Aerosol Test Chamber. Methodologically, the Large Eddy Simulation approach is used, in ... -
Consequence assessment of indoor dispersion of sarin-A hypothetical scenario
Endregard, Monica; Reif, Bjørn Anders Pettersson; Vik, Thomas; Busmundrud, Odd (2010)The objective of this study is to provide a hypothetical scenario of indoor dispersion of the highly toxic nerve agent sarin in a large building, which can be used as a starting point for discussion, planning, training and ... -
Flow noise reduction from superhydrophobic surfaces
Elboth, Thomas; Reif, Bjørn Anders Pettersson; Andreassen, Øyvind; Martell, Michael B. (2012)This work investigates how a highly (super)hydrophobic surface can be used to reduce turbulence-generated drag and noise on a towed streamer cable. The work is done by analyzing full-scale drag and flow noise measurements ... -
Hydrodynamical simulations in FLUENT
Wasberg, Carl Erik; Reif, Bjørn Anders Pettersson (2010)A methodology for hydrodynamical simulations in FLUENT is described. The current application is the computational fluid dynamics analyses of two- and three-dimensional wings conducted as part of an underwater towing ... -
The impact of flow noise on towed and hull mounted acoustical sensors : an introductory study
Reif, Bjørn Anders Pettersson; Andreassen, Øyvind (2004)In this introductory study we have assessed the impact of turbulence generated wall-pressure fluctuations on surfacemounted acoustical sensors, with a special focus on towed sonar arrays. The main findings are that the ... -
Implementation of a new and improved evaporation model in Fluent
Vik, Thomas; Reif, Bjørn Anders Pettersson (2011-01-13)The release and dispersion of toxic chemicals can cause a threat to military personnel and the population at large. In order to develop and implement appropriate protective capabilities and plan mitigating measures, ... -
Large-eddy simulation of dense gas dispersion over a simplified urban area
Wingstedt, Emma My Maria; Osnes, Andreas Nygård; Åkervik, Espen; Eriksson, Daniel; Reif, Bjørn Anders Pettersson (2017)Dispersion of neutral and dense gas over a simplified urban area, comprising four cubes, has been investigated by the means of large-eddy simulations (LES). The results have been compared to wind tunnel experiments and ... -
Large-eddy simulations of dense-gas dispersion within a high-Reynolds number turbulent boundary layer
Wingstedt, Emma My Maria; Vartdal, Magnus; Reif, Bjørn Anders Pettersson (2017)Large-eddy simulations of flows over a backward-facing step with release of four different gases with increasing densities have been performed. The results have been analysed with particular emphasis on the part of the ... -
A model for the viscous dissipation rate in stably stratified, sheared turbulence
Fossum, Hannibal Eie; Wingstedt, Emma My Maria; Reif, Bjørn Anders Pettersson (2013)A model for the turbulence dissipation rate in stably stratified shear turbulence is developed and validated. The functional dependence of the model is derived from first principles and it represents a conceptually new ... -
Modeling the evaporation from a thin liquid surface beneath a turbulent boundary layer
Vik, Thomas; Reif, Bjørn Anders Pettersson (2010)The release and dispersion of toxic chemicals can cause a threat to military personnel and the population at large. In order to develop and implement appropriate protective capabilities and plan mitigating measures, ... -
A modelling study of the flow pattern in a rotating drum for aerosol aging
Reif, Bjørn Anders Pettersson; Wingstedt, Emma M. M.; Pedersen, Kristin (2009)Aerosols are small droplets or particles suspended in a gas and they can contain microorganisms or other harmful substances. It is therefore of great importance to gain more knowledge about them, for example their survival ... -
MODITIC : modelling the dispersion of toxic industrial chemicals in urban environments
Endregard, Monica; Burkhart, Stephane; Burman, Jan; Gentilhomme, Olivier; Robins, Alan; Wingstedt, Emma M. M.; Reif, Bjørn Anders Pettersson; Persson, Leif; Brännström, Niklas; Parmhed, Oskar (2016-10-13)The main objective of the MODITIC (Modelling the disperison of toxic industrial chemicals in urban environments) project is to enhance our fundamental understanding of the physical processes and the associated challenges ... -
Numerical simulations of flow-induced vibrations on Orion P-3C
Reif, Bjørn Anders Pettersson; Wasberg, Carl Erik (2003)The radome mounted on the Orion P-3C has a significant adverse impact on the performance of the aircraft. Measurements have revealed low-frequency vibrations so severe that operational restrictions have been imposed. ... -
Numerical simulations of particle dispersion in an urban area
Wingstedt, Emma M. M.; Reif, Bjørn Anders Pettersson (2012-06-27)In this study the transport and deposition of particles released from different source locations, and with different wind conditions, in a realistic urban area have been investigated. Two different scenarios have been ... -
On the Use of Computational Fluid Dynamics to Investigate Aerosol Dispersion in an Industrial Environment: A Case Study
Fossum, Hannibal Eie; Reif, Bjørn Anders Pettersson; Tutkun, Murat; Gjesdal, Thor (2012)Aerosol dispersion in the area surrounding an existing biological treatment facility is investigated using large-eddy simulation, with the objective to investigate the applicability of computational fluid dynamics to complex ... -
Particle-resolved simulations of shock-induced flow through particle clouds at different Reynolds numbers
Osnes, Andreas Nygård; Vartdal, Magnus; Omang, Marianne Gjestvold; Reif, Bjørn Anders Pettersson (2020-01-27)This study investigates the Reynolds-number dependence of shock-induced flow through stationary particle clouds at 10% volume fraction, using ensemble-averaged results from three-dimensional particle-resolved large eddy ... -
Påvisning av Legionella spp. i luft ved Borregaard
Blatny, Janet Martha; Skogan, Gunnar; Reif, Bjørn Anders Pettersson (2007)Rapporten beskriver et samarbeidsprosjekt mellom Forsvarets forskningsinstitutt (FFI), Folkehelseinstituttet, Telelab AS og Borregaard for å undersøke om ����� legionellabakterier kan påvises i luft ����� legionellabakterier ...