Blar i NTNU Open på forfatter "Gruber, Andrea"
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Computation and prediction of intrinsic thermoacoustic oscillations associated with autoignition fronts
Gopalakrishnan, Harish Subramanian; Gruber, Andrea; Moeck, Jonas (Peer reviewed; Journal article, 2023)A sequential combustor architecture consists of two longitudinally staged combustion zones featuring a propagation-stabilized flame in the first stage and an autoignition-stabilized flame in the second (reheat) stage. This ... -
Computation of Intrinsic Instability and Sound Generation From Autoignition Fronts
Gopalakrishnan, Harish Subramanian; Gruber, Andrea; Moeck, Jonas (Peer reviewed; Journal article, 2022)Burning carbon-free fuels such as hydrogen in gas turbines promise power generation with minimal emissions of greenhouse gases. A two-stage sequential combustor architecture with a propagation-stabilized flame in the first ... -
Computational analysis of premixed methane-air flame interacting with a solid wall or a hydrogen porous wall
Salimath, Prashant; Ertesvåg, Ivar Ståle; Gruber, Andrea (Peer reviewed; Journal article, 2020)The process of flame-wall interaction for premixed methane-air flames is investigated by direct numerical simulation. The flames propagate towards an isothermal, chemically inert surface, consisting of either a solid ... -
Curvature effects on NO formation in wrinkled laminar ammonia/hydrogen/nitrogen-air premixed flames
Netzer, Corinna; Ahmed, Ahfaz; Gruber, Andrea; Løvås, Terese (Peer reviewed; Journal article, 2021)The formation of nitrogen oxide (NO) in wrinkled laminar NH3/H2/N2-air premixed flames is investigated utilizing two-dimensional Direct Numerical Simulation (DNS) with detailed chemical kinetics as well as one-dimensional ... -
Development and validation study of a 1D analytical model for the response of reheat flames to entropy waves
Gant, Francesco; Gruber, Andrea; Bothien, Mirko R. (Peer reviewed; Journal article, 2020)Numerical simulations of laminar premixed flames burning hydrogen and methane in spontaneous ignition mode are performed by harmonically exciting the reactants’ temperature at the domain inlet. The results are compared to ... -
Direct Numerical Simulation of hydrogen combustion at auto-ignitive conditions: Ignition, stability and turbulent reaction-front velocity
Gruber, Andrea; Bothien, Mirko R.; Ciani, Andrea Camperio; Aditya, Konduri; Chen, Jacqueline H.; Williams, Forman Arthur (Peer reviewed; Journal article, 2021)Direct Numerical Simulations (DNS) are performed to investigate the process of spontaneous ignition of hydrogen flames at laminar, turbulent, adiabatic and non-adiabatic conditions. Mixtures of hydrogen and vitiated air ... -
Direct numerical simulation of spray droplet evaporation in hot turbulent channel flow
Lupo, Giandomenico; Gruber, Andrea; Brandt, Luca; Duwig, Christophe (Peer reviewed; Journal article, 2020)We perform a direct numerical simulation (DNS) of 14081 “cold” spherical droplets evaporating in a “hot” fully-developed turbulent channel flow. This effort is the first extensive computation that employs four-way coupling ... -
Direct Numerical Simulation Of Turbulent Combustion Near Solid Surfaces
Gruber, Andrea (Doktoravhandlinger ved NTNU, 1503-8181; 2006:14, Doctoral thesis, 2006)This study uses Direct Numerical Simulation of turbulent reacting compressible plane channel flow at low Reynolds number in order to understand the physics of the interaction of a flame with the turbulent boundary layer ... -
Direct numerical simulations of premixed and stratified flame propagation in turbulent channel flow
Gruber, Andrea; Richardson, Edward S.; Aditya, Konduri; Chen, Jacqueline H. (Journal article; Peer reviewed, 2018)Direct numerical simulations are performed to investigate the transient upstream flame propagation (flashback) through homogeneous and fuel-stratified hydrogen-air mixtures transported in fully developed turbulent channel ... -
DNS of acoustic Instabilities in low Emission Combustion Systems
Austarheim, Nikolai (Master thesis, 2013)In a state of the art gas turbine using Lean Pre-Mixed fuels one of the main challenges is efficient and reliable control of sound generated during combustion. Knowledge of sound generation in gas turbine combustion chambers ... -
Dynamics and stability of autoignition fronts in elementary reheat combustor configurations
Gopalakrishnan, Harish Subramanian (Doctoral theses at NTNU;2022:371, Doctoral thesis, 2022)Stringent regulations on greenhouse gas emissions from gas turbines used for land-based and aircraft applications has resulted in a gradual transition towards carbon-free fuels such as hydrogen. Conventional single-stage ... -
The effect of pressure on lean premixed hydrogen-air flames
Rieth, Martin; Gruber, Andrea; Chen, Jacqueline H. (Journal article; Peer reviewed, 2023)The effect of pressure on the propagation of lean premixed hydrogen-air flames is investigated numerically with a hierarchy of canonical configurations including direct numerical simulations of turbulent flames in homogeneous ... -
Fundamental Modeling of a Membrane Reactor with in Situ Hydrogen Separation and Combustion
Weydahl, Torleif; Salimath, Prashant Siddlinggayya; Gruber, Andrea (Journal article; Peer reviewed, 2013)In this work we consider a membrane reactor with catalytic steam methane reforming and/or water gas shift on the feed side, hydrogen separation and direct combustion of hydrogen on the permeate side, where the ultimate ... -
Numerical investigation of lean premixed ammonia/hydrogen/nitrogen-air flame at blow-out
Aannestad, Jonas Trygve (Master thesis, 2023)I denne avhandlingen gjennomføres en studie av turbulent flammer ved utblåsning ved hjelp av Large-Eddy Simulation (LES) i en bluff-body brenner. Avhandlingen har som mål å vurdere OpenFOAMs løser for turbulent reaktiv ... -
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 ... -
Premixed hydrogen-air flames interacting with a hydrogen porous wall
Salimath, Prashant Siddlinggayya; Ertesvåg, Ivar Ståle; Gruber, Andrea (Journal article; Peer reviewed, 2018)A laminar one-dimensional hydrogen-air flame travelling and quenching towards a chemically inert permeable wall (PW) is studied. Hydrogen flows through the wall into the premixed H2-air. The S3D numerical code with detailed ... -
Response of Autoignition-Stabilized Flames to One-Dimensional Disturbances: Intrinsic Response
Gopalakrishnan, Harish Subramanian; Gruber, Andrea; Moeck, Jonas (Peer reviewed; Journal article, 2021)Burning carbon-free fuels such as hydrogen in gas turbines promises power generation with strongly reduced greenhouse gas emissions. A two-stage combustor architecture with a propagation-stabilized flame in the first stage ... -
Study of flame-flow interactions in turbulent boundary layer premixed flame flashback over a flat plate using direct numerical simulation
Chen, Guo; Wang, Haiou; Gruber, Andrea; Luo, Kun; Fan, Jianren (Journal article; Peer reviewed, 2023)Lean hydrogen/air premixed flame flashback in a turbulent boundary layer over a flat plate is investigated using three-dimensional direct numerical simulation with detailed chemical kinetics. The upstream propagation of ...