Blar i NTNU Open på forfatter "Ertesvåg, Ivar Ståle"
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Experimental study of smouldering in wood pellets with and without air draft
Rebaque, Virginia; Ertesvåg, Ivar Ståle; Mikalsen, Ragni Fjellgaard; Steen-Hansen, Anne (Journal article; Peer reviewed, 2020)Dry wood pellets (diameter 8 mm) of mixed Norwegian spruce and pine were tested in samples of 1.25 kg (1.7 l) in configurations with and without air draft from below. The pellets were placed in a vertical 15 cm diameter ... -
Fire spread in a large compartment with exposed cross-laminated timber and open ventilation conditions: #FRIC-01 – Exposed ceiling
Bøe, Andreas Sæter; Friquin, Kathinka Leikanger; Brandon, Daniel; Steen-Hansen, Anne Elise; Ertesvåg, Ivar Ståle (Peer reviewed; Journal article, 2023)Exposing cross-laminated timber (CLT) structures in buildings is increasingly popular in modern buildings. However, large timber surfaces, window facades, and different geometries can change the fire dynamics in a compartment. ... -
Fire spread in a large compartment with exposed cross-laminated timber and open ventilation conditions: #FRIC-02 - Exposed wall and ceiling
Bøe, Andreas Sæter; Friquin, Kathinka Leikanger; Brandon, Daniel; Steen-Hansen, Anne Elise; Ertesvåg, Ivar Ståle (Journal article; Peer reviewed, 2023)Cross-laminated timber (CLT) is becoming increasingly popular due to its many advantages. However, it has been shown that exposed CLT can have a significant effect on fire dynamics and spread rates. Further studies are ... -
Gas turbine exhaust gas heat recovery by organic Rankine cycles (ORC) for offshore combined heat and power applications - Energy and exergy analysis
Nami, Hossein; Ertesvåg, Ivar Ståle; Otero, Roberto Agromayor; Riboldi, Luca; Nord, Lars O. (Journal article; Peer reviewed, 2018)Effective heat and power supply to offshore installations leads to environmental benefits, but the efficiency is often limited by requirements and constraints connected to the offshore environment. An exergetic analysis ... -
Heat generation and conduction in combined ultrasound imaging and therapy transducers
Nydal, Britt Ingunn (Master thesis, 2017)In this thesis, the heat sources and heat transfer in high power, multifrequency transducers to be used for both ultrasound imaging and mediation of drug delivery, are studied. Electrical energy is converted into acoustic ... -
Integrated multiscale simulation of CHP based district heating system
Li, Peifeng; Nord, Natasa; Ertesvåg, Ivar Ståle; Ge, Zhihua; Yang, Zhiping; Yang, Yongping (Journal article; Peer reviewed, 2015)Many studies have been carried out separately on combined heat and power and district heating. However, little work has been done considering the heat source, the district heating network and the heat users simultaneously, ... -
Investigations of the extended Eddy Dissipation Concept formulation for weakly turbulent and slow chemistry flames
Putra, Bima Anggun; Ertesvåg, Ivar Ståle (Peer reviewed; Journal article, 2023)Recent extensions of the Eddy Dissipation Concept (EDC) are investigated with the purpose of analysing the importance of model limiters to the EDC performance when predicting Moderate and Intense Low-oxygen Dilution (MILD) ... -
Irreversibility of combustion, heat and mass transfer
Nadim, Pedram (Master thesis, 2011)Combustion is by far the most commonly used technology for energy conversion. The analysis of entropy generation and exergy loss is normally used to optimize thermal energy technologies such as gas turbines. The loss of ... -
Jet fires
Bolstad, Marius Olof (Master thesis, 2016)Knowledge of the impacts of fire is a big part of hazard analysis, and thorough fire predictions could potentially save both life and belongings. In the 1990 s, a set of fire tests on compartment fires was conducted at ... -
Large-eddy simulations of the flow over a semi-circular cylinder at Re = 50000
Lysenko, Dmitry A; Donskov, Mark; Ertesvåg, Ivar Ståle (Journal article, 2021)Large-eddy simulations (LES) of the flow over a semi-circular cylinder at a diameter-based Reynolds number 50000 and zero angle of attack are presented. In comparison with the prominent benchmark flows past circular and ... -
Large-eddy simulations of the flow past a bluff-body with active flow control based on trapped vortex cells at Re = 50000
Lysenko, Dmistry A.; Donskov, Mark; Ertesvåg, Ivar Ståle (Peer reviewed; Journal article, 2023)We investigate a novel flow control concept, which allows to govern bluff-body wake dynamics and the laminar–turbulent transition by suppressing vortex shedding and obtaining the mostly detached flow. Large-eddy simulations ... -
LNG - Leakage, spreading and fire
Skinnemoen, Magnus M (Master thesis, 2016)This master s thesis continues the line of LNG related theses in cooperation with ComputIT AS. The Phoenix series large-scale LNG pool fire experiments have been simulated using the CFD software Kameleon FireEx (KFX) for ... -
Local entropy generation and entropy fluxes of a transient flame during head-on quenching towards solid and hydrogen-permeable porous walls
Salimath, Prashant; Ertesvåg, Ivar Ståle (Peer reviewed; Journal article, 2021)Premixed H2-air flames are studied in a one-dimensional wall-bounded configuration. The laminar flame propagates towards and quenches at a wall that is either solid or permeable. Entropy generation by each of 19 elementary ... -
Modellering av NOx frå forbrenning
Grotle, Erlend Liavåg (Master thesis, 2008)Føremålet med denne oppgåva har vore å setje seg inn i modellering av turbulent forbrenning og nytte teori i praksis ved simulering med dataprogrammet SPIDER. Rett modellering er viktig sidan både turbulens og forbrenning ... -
Modelling CO2 - water mixture thermodynamics using various equations of state (EoSs) with emphasis on the potential of the SPUNG EoS
Ibrahim, Mohamed; Skaugen, Geir; Ertesvåg, Ivar Ståle; Haug-Warberg, Tore (Journal article; Peer reviewed, 2014)CO2–water is a very important mixture in the Carbon Capture and Storage (CCS) industry. The mixture can have a broad range of concentrations, from water as an impurity in CO2 transport to high water concentrations in ... -
Modelling CO2-water thermodynamics using SPUNG equation of state (EOS) concept with various reference fluids
Ibrahim, Mohamed; Skaugen, Geir; Ertesvåg, Ivar Ståle (Journal article; Peer reviewed, 2014)Due to the continuous increase of CO2 emission to environment, the Carbon Capture and Storage (CCS) processes gained a very high importance in the last decades. One common CO2 impurity during various CCS processes is water. ... -
Multifysikk simulering av fysiske prosesser med ulike tidskonstanter
Samee, Saber (Master thesis, 2019)Reservoarsimuleringer kan være kostbare og tidkrevende da et typisk reservoar kan være i størrelsesorden av hundrevis av millioner kubikkmeter og produsere i flere tiår. I et forsøk på å redusere simuleringstiden samtidig ... -
Numerical modeling of pool spreading, heat transfer and evaporation in liquefied natural gas (LNG)
Myrmo, Øystein (Master thesis, 2011)This master's thesis is a continuation of previous theses written at ComputIT AS. It treats heat transfer to LNG pools boiling on water through two heat transfer models, LNGSIM1 and LNGSIM2. LNGSIM1 utilizes heat transfer ... -
Numerical modeling of turbulence above helidecks
Mentzoni, Fredrik (Master thesis, 2014)New regulations in the second edition of NORSOK Standard C-004, released in May 2013, require the use of a Reynolds stress transport model for numerical simulations of turbulence above helidecks on the Norwegian continental ... -
Numerical simulations of combustion near solid and hydrogen permeable walls
Salimath, Prashant S. (Doctoral theses at NTNU;2021:306, Doctoral thesis, 2021)The goal of the present thesis was to investigate a selective and isothermal, chemically inert hydrogen-permeable or porous wall boundary condition to laminar flame simulations to understand the flow physics of near-wall ...