Browsing NTNU Open by Author "Æsøy, Eirik"
Now showing items 1-15 of 15
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Acoustic-Convective Interference in Transfer Functions of Methane/Hydrogen and Pure Hydrogen Flames
Æsøy, Eirik; Aguilar, Jose; Bothien, Mirko R.; Worth, Nicholas; Dawson, James (Peer reviewed; Journal article, 2021)We investigate the occurrence and source of modulations in the gain and phase of flame transfer functions (FTF) measured in perfectly premixed, bluff body stabilized CH4=H2 and pure H2 flames. The modulations are shown to ... -
An Improved Method for Determining Near‐Surface Currents From Wave Dispersion Measurements
Smeltzer, Benjamin Keeler; Æsøy, Eirik; Ådnøy, Anna; Ellingsen, Simen Andreas Ådnøy (Journal article; Peer reviewed, 2019)A new inversion method for determining near‐surface shear currents from a measured wave spectrum is introduced. The method is straightforward to implement and starts from the existing state‐of‐the‐art technique of assigning ... -
The Effect of Hydrogen Enrichment on the Thermoacoustic Behaviour of Lean Premixed Flames
Æsøy, Eirik (Doctoral theses at NTNU;2022:23, Doctoral thesis, 2022)Gas turbines (GT) burning hydrogen can help deliver large-scale zero carbon power generation and facilitate rapid decarbonisation over the short to medium term. They can also play a crucial role in increasing the penetration ... -
The effect of hydrogen enrichment, flame-flame interaction, confinement, and asymmetry on the acoustic response of a model can combustor
Æsøy, Eirik; Indlekofer, Thomas; Gant, Francesco; Cuquel, Alexis; Bothien, Mirko R.; Dawson, James Richard (Peer reviewed; Journal article, 2022)To maximise power density practical gas turbine combustion systems have several injectors which can lead to complex interactions between flames. However, our knowledge about the effect of flame-flame interactions on the ... -
The Effect of Hydrogen On Non-linear Flame Saturation
Æsøy, Eirik; Indlekofer, Thomas; Bothien, Mirko; Dawson, James (Peer reviewed; Journal article, 2023)We investigate the effect of hydrogen enrichment on the non-linear response and saturation of premixed methane/hydrogen flames submitted to acoustic forcing. The thermal power is kept fixed to preserve the nozzle velocity ... -
Experimental study of surface waves on strongly sheared currents - Laboratory, design, building, testing, and measurements
Æsøy, Eirik (Master thesis, 2017)In this thesis experimental methods to measure shear-dependent wave dispersion is implemented and used to study waves propagating on currents. To achieve such measurements one needs to establish the following measurement ... -
The influence of hydrogen on the stability of a perfectly premixed combustor
Aguilar, Jose; Æsøy, Eirik; Dawson, James Richard (Journal article; Peer reviewed, 2022) -
Mitigating Thermoacoustic Instabilities in Premixed Hydrogen Flames using Axial Staging
Ånestad, Aksel; Æsøy, Eirik; Dawson, James; Worth, Nicholas Alexander (Journal article; Peer reviewed, 2024)In this paper we demonstrate how axial staging can be utilised to mitigate thermoacoustic instabilities in a combustion system by flame redistribution. This is achieved by moving flow to a second stage flame while keeping ... -
Observation of surface wave patterns modified by sub-surface shear currents
Smeltzer, Benjamin Keeler; Æsøy, Eirik; Ellingsen, Simen Andreas Ådnøy (Journal article; Peer reviewed, 2019)We report experimental observations of two canonical surface wave patterns – ship waves and ring waves – skewed by sub-surface shear, thus confirming effects predicted by recent theory. Observed ring waves on a still surface ... -
The response of an axisymmetric jet placed at various positions in a standing wave
Æsøy, Eirik; Aguilar, Jose; Worth, Nicholas; Dawson, James (Peer reviewed; Journal article, 2021)The hydrodynamic response of an axisymmetric jet placed at various positions in a standing wave oriented normally to the jet is investigated. At the velocity and pressure nodes the axisymmetric (m=0) and first azimuthal ... -
Scaling and prediction of transfer functions in lean premixed H2/CH4-flames
Æsøy, Eirik; Aguilar, Jose; Wiseman, Samuel; Bothien, Mirko R.; Worth, Nicholas; Dawson, James (Journal article, 2020)Features of the flame transfer function (FTF) are characterized for turbulent, non-swirled, bluff body stabilized “M” flames for different hydrogen and methane blends including pure hydrogen flames. An increase in the ... -
Suppression of self-excited thermoacoustic instabilities by convective-acoustic interference
Æsøy, Eirik; Jankee, Girish Kumarsing; Yadala, Srikar; Worth, Nicholas; Dawson, James (Peer reviewed; Journal article, 2022)In this paper we demonstrate direct suppression of self-excited thermoacoustic instabilities over a range of operating conditions using targeted convective-acoustic interference. Premixed hydrogen enriched methane-air ... -
Systematic modulation of the flame transfer function and its effect on thermoacoustic stability
Æsøy, Eirik; Dawson, James Richard; Moeck, Jonas (Journal article; Peer reviewed, 2024)We investigate the thermoacoustic response of a simple laboratory combustor where the flame response is varied systematically by combining hydrogen enrichment with coherent vortex shedding to introduce modulations in the ... -
Tailoring the gain and phase of the flame transfer function through targeted convective-acoustic interference
Æsøy, Eirik; Nygård, Håkon Tormodsen; Worth, Nicholas; Dawson, James Richard (Peer reviewed; Journal article, 2022)This paper investigates how targeted interference between two well characterized sources of hydrodynamic disturbances can modify the response of premixed bluff body stabilised flames with and without swirl. We introduce ... -
The effect of hydrogen enrichment and geometry change on the thermoacoustic instabilities of a premixed lab-scale flame
Mysen, Anders (Master thesis, 2024)Denne masteroppgaven analyserer påvirkningen av hydrogentilførsel og geometriendringer i et forenklet forbrenningskammer. Denne hydrogentilførselen er et nødvendig steg i retningen i kampen mot klimagassutslipp fordi det ...