Browsing NTNU Open by Author "Løvås, Terese"
Now showing items 1-20 of 81
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A Dimensional-Decomposition Approach for Stochastic Scale-Resolving Simulations of Turbulent Reacting Flows
Grøvdal, Fredrik (Doctoral theses at NTNU;2018:399, Doctoral thesis, 2018)High-fidelity and reliable numerical design tools are main keys to the development of novel gas turbines for hydrogen-rich fuels. However, state-of-the-art simulation tools for the most part only give a bulk approximation ... -
A Parametric Study of LEM3D Based on Comparison with a Turbulent Lifted Hydrogen Jet Flame in a Vitiated Co-Flow
Grøvdal, Fredrik; Sannan, Sigurd; Chen, Jyh-Yuan; Løvås, Terese (Journal article; Peer reviewed, 2019)A novel model, the hybrid RANS-LEM3D model, is applied to a lifted turbulent N 2 diluted hydrogen jet flame in a vitiated co-flow of hot products from lean H 2 /air combustion. In the present modeling approach, mean-flow ... -
A thermogravimetric and kinetic study on devolatilization of biomass
Nguyen Cong, Thanh (Master thesis, 2018)The pyrolysis characteristics of spruce wood and birch wood, both of two different particle sizes: 0.063-0.1 mm and 0.2-0.3 mm were investigated using thermogravimetric analyzer. The pyrolysis process was subdivided into ... -
Ammonia in Dual-Fueled Internal Combustion Engines: Impact on NOx, N2O, and Soot Formation
Pedersen, Krister Aaen; Lewandowski, Michal Tadeusz; Netzer, Corinna; Pasternak, Michal; Løvås, Terese (Peer reviewed; Journal article, 2023)The combustion of ammonia in internal combustion engines (ICE) releases nitrogen-related exhaust emissions. Numerous studies have shown that the increased formation of nitrous oxide (N2O) may offset ammonia’s carbon-free ... -
Ammonia Spray Characterization
Borsheim, Nina (Master thesis, 2023)Det er et økende fokus på å få ned klimautslipp, og et ønske om å minske forurensning knyttet til transport og forbrenning. Dette har gjort ammoniakk til et potensielt lovende karbonfritt drivstoff for forbrenningsmotoren, ... -
An Alternative Approach for the Estimation of Biochar Yields
Weber, Kathrin; Heuer, Sebastian; Quicker, Peter; Li, Tian; Løvås, Terese; Scherer, Viktor (Journal article; Peer reviewed, 2018)In this study, a novel approach for the determination of the solid mass yield from slow pyrolysis based on a comparison of the volatile matter contents of feedstock and char is presented. The approach was tested with ... -
An evaluation of effects of fuel parameters and flue gas recirculation on NOx emissions through detailed chemical kinetics simulations
Skreiberg, Øyvind; Li, Tian; Wang, Liang; Bugge, Mette; Løvås, Terese (Journal article; Peer reviewed, 2019)In this work the effects of fuel parameters and under grate flue gas recirculation (FGR) are investigated when applying staged air combustion of solid fuel for the purpose of NOx reduction. In addition to temperatures, ... -
An evaluation of effects of operational parameters on NOx emissions through detailed chemical kinetics simulations
Skreiberg, Øyvind; Li, Tian; Vantaggiato, Elettra; Wang, Liang; Bugge, Mette; Løvås, Terese (Journal article; Peer reviewed, 2019)NOx emissions from biomass and Municipal Solid Waste (MSW) combustion is a great concern. Technologies for reducing NOx emissions based on flue gas cleaning using e.g. Selective Non-Catalytic Reduction (SNCR) or Selective ... -
An SEM-EDX Study of Forest Residue Chars Produced at High Temperatures and High Heating Rate
Wang, Liang; Li, Tian; Matas, Berta Güell; Løvås, Terese; Sandquist, Judit (Journal article; Peer reviewed, 2015)This work investigated morphology, structure and chemical transformation of forest residue chars devolatilized in a drop tube reactor at high heating rates and high temperature conditions. Produced forest residue chars ... -
Application of a Central Composite Design for the Study of NOx Emission Performance of a Low NOx Burner
Dutka, Marcin Damian; Ditaranto, Mario; Løvås, Terese (Journal article; Peer reviewed, 2015)In this study, the influence of various factors on nitrogen oxides (NOx) emissions of a low NOx burner is investigated using a central composite design (CCD) approach to an experimental matrix in order to show the applicability ... -
CFD modeling of biomass combustion and gasification in fluidized bed reactors using a distribution kernel method
Yang, Miao; Zhang, Jingyuan; Zhong, Shenghui; Li, Tian; Løvås, Terese; Fatehi, Hesammedin; Bai, Xue-Song (Peer reviewed; Journal article, 2022)A three-dimensional reactive multi-phase particle-in-cell (MP-PIC) model is employed to investigate biomass combustion and gasification in fluidized bed furnaces. The MP-PIC model considered here is based on a coarse grain ... -
CFD-DEM simulation of biomass gasification with steam in a fluidized BEd reactor
Ku, Xiaoke; Li, Tian; Løvås, Terese (Journal article; Peer reviewed, 2015)A comprehensive CFD–DEM numerical model has been developed to simulate the biomass gasification process in a fluidized bed reactor. The methodology is based on an Eulerian–Lagrangian concept, which uses an Eulerian method ... -
Chemical Model for Thermal Treatment of Sewage Sludge
Netzer, Corinna; Løvås, Terese (Peer reviewed; Journal article, 2022)Sewage sludge is here studied as a valuable source for processing or energy conversation thanks to its high nutrition and energy content. However, various origins of the wastewater, different water cleaning technologies, ... -
CO2 Gasification of Chars Prepared by Fast and Slow Pyrolysis from Wood and Forest Residue: A Kinetic Study
Wang, Liang; Li, Tian; Várhegyi, Gábor; Skreiberg, Øyvind; Løvås, Terese (Journal article; Peer reviewed, 2017)The CO2 gasification of chars was investigated by thermogravimetric analysis (TGA). The chars were prepared from spruce and its forest residue. Prior to the gasification, the raw materials were pelletized and pulverized. ... -
Cold flow characteristics of a novel bluff body hydrogen burner
Meraner, Christoph; Li, Tian; Ditaranto, Mario; Løvås, Terese (Journal article; Peer reviewed, 2018)The cold flow characteristics of a novel partial premixed bluff body (PPBB) low NOx burner, capable of operating with hydrogen as well as methane-hydrogen blends, were investigated numerically. The PPBB burner features a ... -
Comparison of conversion pathways for lignocellulosic biomass to biofuel in Mid-Norway
Berg, Heidi Odegård (Master thesis, 2013)This work investigates one biochemical and one thermochemical biomass-to-liquid biofuel conversion pathway in terms of lignocellulose conversion to liquid Fischer-Tropsch diesel. The focus has been on comparing the two ... -
Comparison of conversion pathways for lignocellulosic biomass to biofuel in Mid-Norway
Berg, Heidi Ødegård (Master thesis, 2013)This work investigates one biochemical and one thermochemical biomass-to-liquid biofuel conversion pathway in terms of lignocellulose conversion to liquid Fischer-Tropsch diesel. The focus has been on comparing the two ... -
Computational fluid dynamic simulations of liquid ammonia spray
Haugsvær, Morten (Master thesis, 2023)For å redusere utslippene innenfor maritim transport, har bruken av ammoniakk i forbrenningsmotorer blitt betraktet som en mulig løsning. Dette er utfordrende på grunn av de dårlige drivstoffsegenskapene samt at forbrenningen ... -
Computational fluid dynamic simulations of thermochemical conversion of pulverized biomass in a dilute flow using spheroidal approximation
Guo, Ning; García Llamas, Ángel David; Li, Tian; Umeki, Kentaro; Gebart, Rikard; Løvås, Terese (Peer reviewed; Journal article, 2020)A drag force model for spheroids, referred as the spheroid model, was implemented in OpenFOAM, in order to better predict the thermochemical conversion of pulverized biomass. Our previous work has found that the spheroid ... -
Computationally efficient coarse-graining XDEM/CFD modeling of fixed-bed combustion of biomass
Zhang, Jingyuan; Li, Tian; Ström, Henrik; Løvås, Terese (Peer reviewed; Journal article, 2022)In the multi-scale modeling of a dense particle system, the particle phase and the gas phase can be modeled on vastly different scales. The coupling between the two models has a critical influence on the predictions obtained ...