Browsing Institutt for energi og prosessteknikk by Document Types "Doctoral thesis"
Now showing items 1-20 of 386
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1-D phenomenological modelling of gas-solid fluidized bed reactors for chemical looping reforming
(Doctoral theses at NTNU;2018:9, Doctoral thesis, 2018)This PhD thesis is a part of the EU FP7 Project called NanoSim. The main objective of this work is to develop a 1-D phenomenological model for fluidized bed reactors to simulate the performance of second-generation CO2 ... -
A 7-field Lagrangian slug capturing and slug tracking model with higher order methods
(Doctoral theses at NTNU;2017:246, Doctoral thesis, 2017)In this thesis, a 7-field Lagrangian slug capturing and slug tracking model with higher order methods and an adaptive grid is investigated for predicting the behaviour of two-phase gasliquid flow in multiphase flow pipelines. ... -
A Dimensional-Decomposition Approach for Stochastic Scale-Resolving Simulations of Turbulent Reacting Flows
(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 Field Study of Reduced Axial Compressor Performance Deterioration through Online Washing and Air Intake Filtration Upgrade
(Doctoral theses at NTNU;2018:300, Doctoral thesis, 2018)Background Oil and gas production at several North Sea offshore installations is limited by the gas turbine power available, and any deterioration in gas turbine performance directly affects production rates. Fouling in ... -
A framework for mixing-reaction closure with the Linear Eddy Model
(Doktoravhandlinger ved NTNU, 1503-8181; 2010:53, Doctoral thesis, 2010)This thesis presents a novel framework for mixing-reaction closure build on the Linear Eddy Model by Kerstein (1991B). The development of the modeling concept has been motivated by the need for better predictive tools for ... -
A framework for modeling internal mass transfer in atmospheric freeze drying
(Doktoravhandlinger ved NTNU, 1503-8181; 2011:106, Doctoral thesis, 2011)In modeling of atmospheric freeze drying (AFD), the modeling of the product is often confined to either one-dimensional models or multi-dimensional models of very basic geometries. Such models are not able to handle a ... -
A Lagrangian Slug Capturing Scheme for Gas-Liquid Flows in Pipes
(Doktoravhandlinger ved NTNU, 1503-8181; 2007:145, Doctoral thesis, 2007)In this thesis a new Lagrangian numerical scheme for the simulation of gas-liquid flows in pipelines is presented. Based on an approximate two-fluid model, this new scheme, called LASSI (Lagrangian Approximate Scheme for ... -
A Multiphase Pump Experimental Analysis
(Doctoral thesis at NTNU;2016:215, Doctoral thesis, 2016)This research project focuses on the characterization of the behaviour of a mixed-flow pump under off-design conditions and two-phase operation, in terms of performance degradation and instabilities. The recent multiphase ... -
A New Extended Corresponding States Equation of State for Modelling CO2-Water Thermodynamics - A Compromise for CFD
(Doctoral theses at NTNU;2017:264, Doctoral thesis, 2017)This PhD work is part of the CO2 Dynamics project in collaboration with Sintef Energy. We investigated the importance of accurate modelling of CO2 thermodynamic properties for process design. The study was conducted for ... -
A Nonsmooth Approach to Modeling and Optimization - Application to Liquefied Natural Gas Processes and Work and Heat Exchange Networks
(Doctoral theses at NTNU;2020:54, Doctoral thesis, 2020)Despite their implicit presence in many process systems engineering applications, nonsmooth functions have repeatedly been shunned due to the existence of nondifferentiable points that cause issues for numerical solvers ... -
A roll wave and slug tracking scheme for gas-liquid pipe flow
(Doktoravhandlinger ved NTNU, 1503-8181; 2010:59, Doctoral thesis, 2010)The main objective of this work is to explore ways of introducing large roll waves as computational objects into a one-dimensional slug tracking scheme for gas-liquid pipe flow. The tracking scheme uses a moving and adaptive ... -
A solar concentrator with heat storage and self-circulating liquid
(Doktoravhandlinger ved NTNU, 1503-8181; 2013:164, Doctoral thesis, 2013)The main objective of this thesis is to design and test a solar concentrating collector with heat storage for domestic applications, mainly solar cooking. The system must be cheap, robust, easy to use and maintain, and ... -
A Study of Ultra-Low Temperature Application for Fish Freezing and Storing
(Doktoravhandlinger ved NTNU, 1503-8181; 2014:128, Doctoral thesis, 2014)This work was performed in order to get information about the economic benefit of maintaining the quality and increasing the shelf-life of fish using ultra-low temperature (between –30.0 and –85.0 °C). The scope of the ... -
A theoretical and experimental study of the thermal degradation of biomass
(Dr.ingeniøravhandling, 0809-103X; 1996:115, Doctoral thesis, 1996) -
A Treatise on Interpolar Transport Phenomena
(Doktoravhandlinger ved NTNU, 1503-8181; 2012:201, Doctoral thesis, 2012)This thesis contributes to the understanding of mechanisms for mass transport in aluminium electrolysis cells. Fundamental studies are undertaken of ow patterns and mass transport in the interpolar region under various ... -
The actuator disk as a wind turbine model: An experimental assessment of the fluid dynamics
(Doctoral theses at NTNU;2023:9, Doctoral thesis, 2023)Climate change is one of the major challenges of our time. With ambitions to keep the average global temperature below 1:5ý C above pre-industrial levels, significant efforts to transform the global energy production from ... -
Adhesion of Bacillus Cereus Spores to Surface
(Dr. ingeniøravhandling, 0809-103X; 2003:93, Doctoral thesis, 2003)This thesis deals with the adhesion and removal of the spore forming pathogenic bacterium Bacillus cereus. The spores of Bacillus cereus are known for being hydrophobic and adhere well to other hydrophobic surfaces. The ... -
Advancements in Automated Methods for Fluid-Dynamic Turbomachinery Design
(Doctoral theses at NTNU;2021:180, Doctoral thesis, 2021)Automated design methods are emerging as a powerful tool for the fluid-dynamic design of turbomachinery components. Such automated methods integrate mathematical models of different level of sophistication with numerical ... -
Advancements in environmentally extended multiregional input-output analysis: modeling drivers, pressures, and impacts
(Doctoral theses at NTNU;2021:210, Doctoral thesis, 2021)We increasingly need to rely on demand side changes to complement technological improvements to mitigate environmental impacts such as global warming and loss of biodiversity. To do so we must better understand how different ... -
Advancing sustainable land and water management strategies for deployment of bioenergy production systems
(Doctoral theses at NTNU, 2022:115, Doctoral thesis, 2022)Bioenergy is a necessity in most climate change mitigation scenario limiting global warming to below 2°C at the end of century relative to pre-industrial times. The large landrequirements associated with large-scale ...