Browsing NTNU Open by Author "Haugen, Nils Erland L"
Now showing items 21-40 of 40
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Investigation of an Innovative Latent Heat Storage Concept in a Stovepipe
Sevault, Alexis; Soibam, Jerol; Haugen, Nils Erland L; Skreiberg, Øyvind (Journal article; Peer reviewed, 2018)Latent heat storage (LHS) is a promising concept for small-scale batch combustion. One example is wood stoves, which rely on a batch combustion process that yields a transient heat production with high peak effect. A ... -
Mechanism of unconfined dust explosions: Turbulent clustering and radiation-induced ignition
Liberman, Michael A.; Kleeorin, Nathan; Rogachevskii, Igor; Haugen, Nils Erland L (Journal article; Peer reviewed, 2017)It is known that unconfined dust explosions typically start off with a relatively weak primary flame followed by a severe secondary explosion. We show that clustering of dust particles in a temperature stratified turbulent ... -
Modeling radiation in particle clouds: on the importance of inter-particle radiation for pulverized solid fuel combustion
Haugen, Nils Erland L; Mitchell, Reginald E. (Journal article; Peer reviewed, 2014)The importance of inter-particle radiation for clusters of gray and diffuse particles is investigated. The radiative cooling of each individual particle is found to vary strongly with its position in the cluster, and a ... -
Multipoint radiation induced ignition of dust explosions: turbulent clustering of particles and increased transparency
Liberman, Michael A.; Kleeorin, Nathan; Rogachevskii, Igor; Haugen, Nils Erland L (Journal article; Peer reviewed, 2018)Understanding the causes and mechanisms of large explosions, especially dust explosions, is essential for minimising devastating hazards in many industrial processes. It is known that unconfined dust explosions begin as ... -
Numerical approaches for thermochemical conversion of char
Haugen, Nils Erland L; Loong, Brandon Ka Yan; Mitchell, Reginald E. (Peer reviewed; Journal article, 2022)This paper gives a review of the current state of the art for numerical simulations of char conversion. In particular, it presents models that have been developed to describe the physical and chemical phenomena that ... -
Numerical Investigation of a Phase Change Materials (PCM) heat exchanger - For small scale combustion appliances.
Soibam, Jerol (Master thesis, 2017)This work mainly focuses on the investigation of heat storage in a PCM, solidification & melting of the PCM and heat release to the surrounding from the storage unit. As the conductivity of PCMs is generally low, fins have ... -
Numerical investigation of free-stream turbulence effects on the transition-in-wake state of flow past a circular cylinder
Aarnes, Jørgen Røysland; Andersson, Helge Ingolf; Haugen, Nils Erland L (Journal article; Peer reviewed, 2018)We investigate how a turbulent free-stream (TFS) affects the transition-in-wake state of flow past a cylinder. Direct numerical simulations of a decaying TFS flow past a cylinder have been performed, where the intensity ... -
Numerical models for thermochemical degradation of thermally thick woody biomass, and their application in domestic wood heating appliances and grate furnaces
Haberle, Inge; Skreiberg, Øyvind; Lazar, Joanna; Haugen, Nils Erland L (Journal article; Peer reviewed, 2017)This paper reviews the current state-of-the-art of numerical models used for thermochemical degradation and combustion of thermally thick woody biomass particles. The focus is on the theory of drying, devolatilization and ... -
Numerical simulations of staged biomass grate fired combustion with an emphasis on NOx emissions
Bugge, Mette; Skreiberg, Øyvind; Haugen, Nils Erland L; Carlsson, Per; Houshfar, Ehsan; Løvås, Terese (Peer reviewed; Journal article, 2015)In the present paper NOx emissions from biomass combustion was studied, with the objective to demonstrate the applicability of stationary computational fluid dynamics simulations, including a detailed representation of the ... -
Numerical Study of Hydrogen Inhibition of Char
Lazar, Joanna Maria (Master thesis, 2015)It has been known for a long time that hydrogen in the gas phase tend to inhibit gasification of char at low and intermediate temperatures. At higher temperatures, however, there are indications that hydrogen may speed up ... -
Numerical Study of Hydrogen Inhibition of Char Gasification Using Detailed Hetero- and Homogeneous Chemical Kinetics
Lazar, Joanna; Haugen, Nils Erland L; Krüger, Jonas; Szlek, Andrzej (Journal article; Peer reviewed, 2016)It has been known for a long time that hydrogen in the gas phase tends to inhibit gasification of char at low and intermediate temperatures. At higher temperatures, however, there are indications that hydrogen may speed ... -
A numerical study on the combustion of a resolved carbon particle
Karchniwy, Ewa Malgorzata; Haugen, Nils Erland L; Klimanek, Adam (Journal article; Peer reviewed, 2021)Combustion of a single, resolved carbon particle is studied using a novel numerical approach that makes use of an overset grid. The model is implemented into the framework of a compressible Direct Numerical Simulation (DNS) ... -
Phase change materials for thermal energy storage in low- and high-temperature applications: a state-of-the-art
Sevault, Alexis; Kauko, Hanne; Bugge, Mette; Banasiak, Krzysztof; Haugen, Nils Erland L; Skreiberg, Øyvind (Research report, 2017) -
Superchilling, ice fraction and quality
Stevik, Astrid; Haugen, Nils Erland L; Duun, Anne Sissel; Walnum, Harald Taxt; Nordtvedt, Tom Ståle (Chapter, 2010)The scope of the current experiments was to superchill a selection of fresh food by two superchilling methods followed by extensive storage studies and monitoring of quality during superchilled storage. Several methods for ... -
The effect of Stefan flow on the drag coefficient of spherical particles in a gas flow
Jayawickrama, Thamali R.; Haugen, Nils Erland L; Bäbler, Matthâus Ulrich; Chishty, Muhammad Aqib; Umeki, Kentaro (Journal article; Peer reviewed, 2019)Particle laden flows with reactive particles are common in industrial applications. Chemical reactions inside the particle can generate a Stefan flow that affects heat, mass and momentum transfer between the particle and ... -
The effect of turbulence on mass transfer rates between inertial polydisperse particles and fluid
Karchniwy, Ewa Malgorzata; Klimanek, Adam F.; Haugen, Nils Erland L (Journal article; Peer reviewed, 2019)The current work investigates how turbulence affects the mass transfer rate between inertial particles and fluid in a dilute, polydisperse particle system. Direct numerical simulations are performed in which all scales of ... -
Thermophoresis and its effect on particle impaction on a cylinder for low and moderate Reynolds numbers
Haugen, Nils Erland L; Krüger, Jonas; Aarnes, Jørgen Røysland; Karchniwy, Ewa Malgorzata; Klimanek, Adam (Peer reviewed; Journal article, 2021)The effect of thermophoresis on the impaction of particles on a cylinder is investigated for different particle sizes, particle conductivities, temperature gradients and for Reynolds numbers between 100 and 1600. This is ... -
Turbophoresis in forced inhomogeneous turbulence
Mitra, Dhrubaditya; Haugen, Nils Erland L; Rogachevskii, Igor (Journal article; Peer reviewed, 2018)We show, by direct numerical simulations, that heavy inertial particles (characterized by Stokes number St) in inhomogeneously forced statistically stationary isothermal turbulent flows cluster at the minima of mean-square ... -
Validation of a numerical approach for simulation of the thermal decomposition behaviour of biomass in grate combustion plants
Bugge, Mette; Haugen, Nils Erland L; Li, Tian; Zhang, Jingyuan; Skreiberg, Øyvind (Journal article; Peer reviewed, 2021) -
Varying the forcing scale in low Prandtl number dynamos
Brandenburg, Axel; Haugen, Nils Erland L; Li, Xiang-Yu; Subramanian, Kandaswamy R. (Journal article; Peer reviewed, 2018)Small-scale dynamos are expected to operate in all astrophysical fluids that are turbulent and electrically conducting, for example the interstellar medium, stellar interiors, and accretion discs, where theymay also be ...