Blar i Institutt for prosess-, energi- og miljøteknologi på forfatter "Lie, Bernt"
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A solution method for one-dimensional shallow water equations using flux limiter centered scheme for open Venturi channels
Welahettige, Prasanna Kumara Welahetti; Vågsæther, Knut; Lie, Bernt (Journal article; Peer reviewed, 2018)The one-dimensional shallow water equations were modified for a Venturi contraction and expansion in a rectangular open channel to achieve more accurate results than with the conventional one-dimensional shallow water ... -
Algorithm with improved accuracy for real-time measurement of flow rate in open channel systems
Agu, Cornelius Emeka; Hjulstad, Åsmund; Elseth, Geir; Lie, Bernt (Journal article; Peer reviewed, 2017)Most methods for flow rate measurement in open channels usually have low accuracy over a range of flow rates due to varying fluid properties, flow conditions and channel length. This paper suggests an algorithm to improve ... -
Computational fluid dynamics study of flow depth in an open Venturi channel for Newtonian fluid
Welahettige, Prasanna Kumara Welahetti; Lie, Bernt; Vågsæther, Knut (Journal article; Peer reviewed, 2017)Open Venturi channel flow measurement could be a cheap method to be used in drill bit pressure control. The main objective of this study is to identify the factors related with the flow depth in an open Venturi channel. A ... -
Computational Fluid Dynamics Study of Shear Thinning Fluid (Drilling Fluid) Viscosity Models in an Open Venturi Channel
Welahettige, Prasanna Kumara Welahetti; Lie, Bernt; Vågsæther, Knut (Journal article; Peer reviewed, 2019)We aim to develop an improved kick/loss detection technology by developing smart flow-sensor technology for returned flow from the oil well in open Venturi channels. This is a detailed study about a capacity of use of ... -
Computational Fluid Dynamics Study of the Effects of Drill Cuttings on the Open Channel Flow
Welahettige, Prasanna Kumara Welahetti; Berg, Christian; Lundberg, Joachim; Lie, Bernt; Vågsæther, Knut (Peer reviewed; Journal article, 2019)A three-dimensional computational fluid dynamics (CFD) study was carried out for drilling fluid flow with drill cuttings in open channels. The flow is similar to the return flow when drilling, stream containing drilling ... -
Flow regime changes at hydraulic jumps in an open Venturi channel for Newtonian fluid
Welahettige, Prasanna Kumara Welahetti; Lie, Bernt; Vågsæther, Knut (Journal article; Peer reviewed, 2017) -
Model Based Early Kick/Loss Detection and Attenuation with Topside Sensing in Managed Pressure Drilling
Jinasena, Asanthi; Holta, Haavard H. F.; Jondahl, Morten Hansen; Welahettige, Prasanna Kumara Welahetti; Aamo, Ole Morten; Sharma, Roshan; Viumdal, Håkon; Lie, Bernt (Peer reviewed; Journal article, 2020)Early kick/loss detection is a crucial part of safe well control, and it plays a major role in the reduction of risk and non-productive time in drilling. In conventional drilling, topside sensing is used for early kick/loss ... -
NEQ rate based modeling of an absorption column for post combustion CO2 capturing
Jayarathna, Sanoja A.; Lie, Bernt; Melaaen, Morten Christian (Journal article; Peer reviewed, 2011-04-01)Post combustion CO2 capture via absorption into aqueous alkanolamine systems is considered to be the most mature and potential technique for CO2 removal from the power plants' exhaust gases. Modeling and simulation of such ... -
One-dimensional model of turbulent flow of non-Newtonian drilling mud in non-prismatic channels
Welahettige, Prasanna Kumara Welahetti; Lundberg, Joachim; Bjerketvedt, Dag; Lie, Bernt; Vågsæther, Knut (Peer reviewed; Journal article, 2019)One-dimensional model of non-Newtonian turbulent flow in a non-prismatic channel is challenging due to the difficulty of accurately accounting for flow properties in the 1-D model. In this study, we model the 1-D Saint–Venant ... -
Oxygen Effects in Anaerobic Digestion II
Botheju, Deshai; Lie, Bernt; Bakke, Rune (Journal article, 2010)Standard models describing bio-gasification using anaerobic digestion do not include necessary processes to describe digester dynamics under the conditions of oxygen presence. Limited oxygenation in anaerobic digestion can ... -
A Real-Time Flow-Measuring Algorithm for Open Venturi Channel Non-Newtonian Flow
Welahettige, Prasanna Kumara Welahetti; Lie, Bernt; Vågsæther, Knut (Peer reviewed; Journal article, 2019)A real-time flow measuring algorithm is developed for the open Venturi channel non-Newtonian flow measurement. Using a single level sensor reading at downstream of the open Venturi channel, a drilling-well return flow rate ... -
Simulation of Transcritical Flow in Hydraulic Structures
Agu, Cornelius Emeka; Lie, Bernt; Elseth, Geir (Journal article; Peer reviewed, 2015-11-25)In hydraulic engineering, transcritical flows are often required in some applications. One example is in a Venturi channel where the occurrence of critical depth is used to estimate flow rate in the channel. In this paper, ... -
Study of Fluidization Regimes using OpenFOAM Computational Fluid Dynamics
Welahettige, Prasanna Kumara Welahetti; Lie, Bernt; Vågsæther, Knut; Moldestad, Britt Margrethe Emilie (Journal article; Peer reviewed, 2017)The objective of this study was using computational fluid dynamics simulation with OpenFOAM to study the fluidization properties for four types of particles classified as Geldart A, B, C and D. Fluidization regimes were ... -
Temperature control of a pilot anaerobic digestion reactor
Haugen, Finn; Bakke, Rune; Lie, Bernt (Journal article; Peer reviewed, 2013)Results of analysis and design and implementation of a temperature control system for a practical pilot anaerobic digestion (AD) bioreactor fed with dairy waste are presented. A dynamic model of the reactor temperature is ...