Blar i NTNU Open på forfatter "Olsen, Nils Reidar Bøe"
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3D NUMERISK MODELLERING AV DELER AV VANNVEGEN TIL TONSTAD KRAFTVERK
Brevik, Oddmund (Master thesis, 2013)Denne masteroppgåva handlar om bruk av numerisk modellering («Computational Fluid Dynamics», CFD) i høve til sandfang 3 ved Tonstad kraftverk. Oppgåva tek utgangspunkt i geometri og feltmålingar frå sandfanget. For å ... -
Calibration of Horizontal Acoustic Doppler Current Profiler by three dimensional CFD simulations
Bråtveit, Kari; Olsen, Nils Reidar Bøe (Journal article; Peer reviewed, 2015)This study presents a calibration method of horizontal acoustic Doppler current profilers (H-ADCP), based on 3D Computational Fluid Dynamics (CFD) simulations. Rigidly mounted H-ACCPs are currently used to continuously ... -
Experimental and Numerical Determination of the Head Loss of a Pressure Driven Flow through an Unlined Rock-Blasted Tunnel
Aberle, Jochen; Henry, Pierre-Yves T; Kleischmann, Fabian; Navaratnam, Christy Ushanth; Vold, Mari; Eikenberg, Ralph; Olsen, Nils Reidar Bøe (Peer reviewed; Journal article, 2020)The friction loss in a part of the rock-blasted unlined tunnel of the Litjfossen hydropowerplant in Norway was determined from experimental and numerical studies. Remote sensing datafrom the prototype tunnel provided the ... -
Explaining the formation of sedimentary structures under antidunes using a 2D width-averaged numerical model
Olsen, Nils Reidar Bøe (Peer reviewed; Journal article, 2022)A new numerical model for computing the formation of sedimentary structures in a fluvial environment is presented. The model has been used to explain the strata-forming processes under antidunes in detail, including water ... -
Finding Free Surface of Supercritical Flows - Numerical Investigation
Feurich, Robert; Olsen, Nils Reidar Bøe (Journal article; Peer reviewed, 2012)A three-dimensional numerical model (STAR-CCM+) has been used to compute the free surface for different cases with supercritical flow. The program solves the Navier-Stokes equations on an unstructured hexahedral grid using ... -
Long-time 3D CFD modelling of sedimentation with dredging in a hydropower reservoir
Olsen, Nils Reidar Bøe; Hillebrand, Gudrun (Journal article; Peer reviewed, 2018)The purpose of the current study was to present a 3D CFD model that can be used to predict long-term (11 years) bed changes in a reservoir due to sedimentation and dredging. And that this can be done with a reasonable ... -
Multiple solutions of the Navier-Stokes equations computing water flow in sand traps
Almeland, Silje Kreken; Olsen, Nils Reidar Bøe; Bråveit, Kari; Aryal, Pravin R. (Journal article; Peer reviewed, 2019)Two cases are presented wherein the main flow pattern in sand traps changes considerably as a function of discretization scheme, grid resolution and turbulence model. Both cases involve channel flows directed into a desilting ... -
A numerical geotechnical model for computing soil slides at banks of water reservoirs
Olsen, Nils Reidar Bøe; Haun, Stefan (Peer reviewed; Journal article, 2020)Soil slides can occur when the water level in a lake or a reservoir is lowered. This may take place in situations when a reservoir is flushed to remove sediments. The current study describes a three-dimensional numerical ... -
Numerical Modeling of Flow Over Trapezoidal Broad-Crested Weir
Haun, Stefan; Olsen, Nils Reidar Bøe; Feurich, Robert (Journal article; Peer reviewed, 2011)Two computational fluid dynamics (CFD) codes, Flow-3D and SSIIM 2, have been used to calculate the water flow over a trapezoidal broad-crested weir. The two programs apply different algorithms for making the grid and ... -
Numerical modelling of bank failures during reservoir draw-down
Olsen, Nils Reidar Bøe; Haun, Stefan (Journal article; Peer reviewed, 2018)Numerical algorithms are presented for modeling bank failures during reservoir flushing. The algorithms are based on geotechnical theory and the limit equilibrium approach to find the location and the depth of the slides. ... -
Numerical modelling of downstream-migrating antidunes
Olsen, Nils Reidar Bøe (Journal article; Peer reviewed, 2017)A numerical model is presented that compute the geometrical dimensions and movement of downstream migrating antidunes. The model solves the Navier–Stokes equations together with the k-epsilon turbulence model to find the ... -
Numerical Simulation of Friction Losses in Tunnels with Strip Roughness
Mølmann, Erik (Master thesis, 2018)To estimate friction introduced by plastering strips inside of laboratory tunnels, an equation named after Reidar Birkeland is used at NTNU. In this thesis, four different geometries with three different strip distances ... -
Numerisk modellering av termodynamiske prosesser i luftputekammer
Kjøren, Erik (Master thesis, 2014)Det er i denne oppgaven utført numeriske simuleringer av en langvarig transient i et luftputekammer. Hovedfokuset har vært å gjenskape data fra feltmålinger av vannstand og trykk i luftputekammer ved magasinbytte i Jukla ... -
An OpenFOAM solver for computing suspended particles in water currents
Olsen, Nils Reidar Bøe; Kadia, Subhojit; Pummer, Elena Marianne; Hillebrand, Gudrun (Peer reviewed; Journal article, 2023)A new OpenFOAM solver has been developed for computing the spatial variation of particle concentrations in flowing water. The new solver was programmed in C ++ using OpenFOAM libraries, and the source code has been made ... -
Sediments in Angostura Hydropower Reservoir
Kjærås, Halvor (Master thesis, 2012)Reservoirs in areas with a high sediment yield will without mitigation sooner or later be filled up with sediments, reducing the volume available for regulation for electric generation. Flushing of sediments is a management ... -
Three-dimensional numerical modeling of water flow in a rock-blasted tunnel
Vold, Mari (Master thesis, 2017)Climate change leads to more intense precipitation in Norway. NVE requires all bypass tunnels have sufficient capacity for bypassing flood water. The hydro-power industry needs a method for establishing tunnel capacity, ... -
Three-Dimensional Numerical Modelling of Water Flow over a Rough Channel Bed
Willmann, Eivind Sønnesyn (Master thesis, 2017)A three-dimensional numerical model is used to simulate the water flow field over a rough channel bed, utilizing the open source computational fluid dynamics toolbox OpenFOAM. The geometry of the numerical model is a ... -
Three-Dimensional Rans Modeling of Flow Around Circular Piers using Nested Grids
Baranya, S; Olsen, Nils Reidar Bøe; Stoesser, T; Sturm, T (Journal article; Peer reviewed, 2012)The paper introduces a three-dimensional numerical model that solves the Reynolds Averaged Navier-Stokes (RANS) equations on a curvilinear grid system using a novel nested grid approach. The main benefit of the model is ... -
Todimensjonal numerisk modellering av strømning i elver og renne
Bjerkeli, Magnus Mikkelsen (Master thesis, 2016)Med siste versjon av Hec-ras er det mulig å beregne todimensjonal vannstrømning i programmet. For å finne ut hvor godt programmet klarer å beregne todimensjonal vannstrømning er det gjort to laboratoriet forsøk, og resultatene ... -
Todimensjonal numerisk modellering av strømning i elver og renne
Bjerkeli, Magnus Mikkelsen (Master thesis, 2016)Med siste versjon av Hec-ras er det mulig å beregne todimensjonal vannstrømning i programmet. For å finne ut hvor godt programmet klarer å beregne todimensjonal vannstrømning er det gjort to laboratoriet forsøk, og resultatene ...