Volume 4A: Combustion, Fuels, and Emissions最新文献

{"title":"Investigation of Fuel and Load Flexibility in a SGT-600/700/800 Burner Under Atmospheric Pressure Conditions Using High-Speed OH-PLIF and OH Chemiluminescence Imaging","authors":"A. Subash, Haisol Kim, Sven-Inge Möller, M. Richter, C. Brackmann, M. Aldén, A. Lantz, A. Lindholm, J. Larfeldt, D. Lörstad","doi":"10.1115/GT2020-14583","DOIUrl":"https://doi.org/10.1115/GT2020-14583","url":null,"abstract":"\u0000 Fuel and load flexibility have been increasingly important features of industrial gas turbines in order to meet the demand for increased utilization of renewable fuels and to provide a way to balance the grid fluctuations due to the unsteady supply of wind and solar power. Experimental investigations were performed using a standard 3rd generation dry low emission (DLE) burner under atmospheric pressure conditions to study the effect of central and pilot fuel addition, load variations and hydrogen (H2) enrichment in a natural gas (NG) flame. High-speed kHz planar laser-induced fluorescence (PLIF) of OH radicals and imaging of OH chemiluminescence were employed to investigate the flame stabilization, flame turbulence interactions, and flame dynamics. Along with the optical measurements, combustion emissions were also recorded to observe the effect of changing operating conditions on NOX level. The burner is used in Siemens industrial gas turbines SGT-600, SGT-700 and SGT-800 with no hardware differences and the study thus is a step to characterize fuel and load flexibility for these turbines. Without pilot and central fuel injections in the current burner configuration, the main flame is stabilized creating a central recirculation zone (CRZ). Addition of the pilot fuel strengthens the outer recirculation zone (ORZ) and moves the flame anchoring position slightly downstream, whereas the flame moves upstream without affecting the ORZ when central fuel injection is added. The flame was investigated utilizing H2/NG fuel mixtures where the H2 amount was changed from 0 to 100%. The results show that the characteristics of the flames are clearly affected by the addition of H2 and by the load variations. The flame becomes more compact, the anchoring position moves closer to the burner exit and the OH signal distribution becomes more distinct for H2 addition due to increased reaction rate, diffusivity, and laminar burning velocity. Changing the load from part to base, similar trends were observed in the flame behavior but in this case due to the higher heat release because of increased turbulence intensity.","PeriodicalId":311793,"journal":{"name":"Volume 4A: Combustion, Fuels, and Emissions","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123317959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CFD-CRN Study of NOx Formation in a High-Pressure Combustor Fired With Lean Premixed CH4 / H2 - Air Mixtures","authors":"A. Vashishtha, Sajjad Yousefian, G. Goldin, K. Frojd, S. Jella, G. Bourque, R. Monaghan","doi":"10.1115/GT2020-14819","DOIUrl":"https://doi.org/10.1115/GT2020-14819","url":null,"abstract":"\u0000 The main motivation of this study is to investigate detailed NOx and CO formation in high-pressure dump combustor fired with lean premixed methane-air mixture using CFD-CRN hybrid approach. Further, this study is extended to investigate the effect of H2 enrichment on emission formation in the same combustor. Three-dimensional steady RANS CFD simulations have been performed using a Flamelet Generated Manifold (FGM) model in Simcenter STAR-CCM+ 2019.2 with the DRM22 reduced mechanism. The CFD simulations have been modelled along with all three heat transfers modes: conduction, convection and radiation. The conjugate heat transfer (CHT) approach and participating media radiation modelling have been used here. Initially, CFD simulations are performed for five lean equivalence ratios (ϕ = 0.43–0.55, Tinlet = 673 K, Vinlet = 40 m/s) of pure methane-air mixture operating at 5 bar. The exit temperature and flame-length are compared with available experimental data. The automatic chemical reactor network has been constructed from CFD data and solved using the recently developed reactor network module of Simcenter STAR-CCM+ 2019.2 in a single framework for each cases. It is found out that the CRNs up to 10,000 PSRs can provide adequate accuracy in exit NOx predictions compared to experiments for pure methane cases. The contribution of NOx formation pathway, changes from N2O intermediate to thermal NO as equivalence ratio increases. Further studies are performed for two equivalence ratios (ϕ = 0.43 and 0.50 to simulate the impact of H2 addition (up to 40% by volume) on NOx formation pathways and CO emission. It is found out here that the contribution from NNH pathway increases for leaner equivalence ratio cases (ϕ = 0.43), while thermal pathway slightly increases for ϕ = 0.50 with increase in H2 content from 0% to 40%.","PeriodicalId":311793,"journal":{"name":"Volume 4A: Combustion, Fuels, and Emissions","volume":"352 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123651938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation on the Fluctuations of the Spray Angle Generated From Pressure-Swirl Atomizers","authors":"Xiwei Wang, Yong Huang, Lei Sun","doi":"10.1115/GT2020-14390","DOIUrl":"https://doi.org/10.1115/GT2020-14390","url":null,"abstract":"\u0000 The unsteady characteristic of the pressure-swirl atomization system was studied experimentally in this paper. It was found that the fluctuations of the spray can be divided into two modes: high and low frequency mode, among which the frequency of the high mode is within the range of 500–1100Hz, and the low mode is 100–400Hz. The low mode depends on the turbulent exchange of momentum between the liquid and the surrounding stagnant gas. While the high mode depends on the comprehensive effect of the turbulent vortex generated by the liquid flowing through the atomizer and the natural frequency of the atomizer. Experiments show that the peak frequency of the low mode increases but the peak frequency of the high mode decreases when the pressure drop of the atomizer increases. When the atomizer outlet area size increases, both the peak frequency of the low mode and the high mode decrease. When the deflection angle of the swirl chamber increases, the peak frequency of the low mode increases, while the peak frequency of the high mode decreases first and then increases, reaching the minimum at 60°, and the value at 45° is basically the same as at 80°.","PeriodicalId":311793,"journal":{"name":"Volume 4A: Combustion, Fuels, and Emissions","volume":"37 9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125735357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Data-Driven Combustion Modeling for a Turbulent Flame Simulated With a Computationally Efficient Solver","authors":"M. Talei, Dominic Ma, R. Sandberg","doi":"10.1115/GT2020-14843","DOIUrl":"https://doi.org/10.1115/GT2020-14843","url":null,"abstract":"\u0000 The use of machine learning (ML) for modeling is on the rise. In the age of big data, this technique has shown great potential to describe complex physical phenomena in the form of models. More recently, ML has frequently been used for turbulence modeling while the use of this technique for combustion modeling is still emerging. Gene expression programming (GEP) is one class of ML that can be used as a tool for symbolic regression and thus improve existing algebraic models using high-fidelity data. Direct numerical simulation (DNS) is a powerful candidate for producing the required data for training GEP models and validation. This paper therefore presents a highly efficient DNS solver known as HiPSTAR, originally developed for simulating non-reacting flows in particular in the context of turbo-machinery. This solver has been extended to simulate reacting flows. DNSs of two turbulent premixed jet flames with different Karlovitz numbers are performed to produce the required data for training. GEP is then used to develop algebraic flame surface density models in the context of large-eddy simulation (LES). The result of this work introduces new models which show excellent performance in prediction of the flame surface density for premixed flames featuring different Karlovitz numbers.","PeriodicalId":311793,"journal":{"name":"Volume 4A: Combustion, Fuels, and Emissions","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132638245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-Frequency Instability Driving Potential of Premixed Jet Flames in a Tubular Combustor due to Dynamic Compression and Deflection","authors":"P. M. Keleshtery, Gerrit Heilmann, C. Hirsch, L. Panek, M. Huth, T. Sattelmayer","doi":"10.1115/GT2020-15048","DOIUrl":"https://doi.org/10.1115/GT2020-15048","url":null,"abstract":"\u0000 Constructive interference of acoustic oscillations and combustion heat release can result in high-frequency thermoacoustic instabilities in gas turbine combustion chambers with strong pressure pulsations. They may cause component wear and limit the safe operating range of the engine. During the development of stable combustors the influence of design variables on the driving mechanisms of these instabilities is of particular interest. This paper studies the influence of design parameters on the linear growth rates of high-frequency thermoacoustic transverse modes in a tubular combustor of hexagonal cross-section equipped with 12 turbulent premixed jet burners. Two flame dynamics models are used, i. e. the dynamic compression and the deflection mechanisms, which have in the past been validated for turbulent swirl burners. To demonstrate the applicability as well as the shortfalls of these flame dynamics models the impact of different geometrical and flow parameters on the driving potential of high-frequency thermoacoustic modes are considered. A parameter variation study of thermal power, air excess ratio, diameter of the combustor and the radial position of jet burners was performed.\u0000 The first transversal eigenmodes and eigenfrequencies were computed by solving the inhomogeneous Helmholtz equation with the flame driving source terms in the frequency domain using the finite element method. The required mean fields of temperature and heat release rate were obtained using a generic flame distribution scaled with respect to the experimental OH* chemiluminescence measurements. The resulting growth rates give a measure for the thermoacoustic driving potential.","PeriodicalId":311793,"journal":{"name":"Volume 4A: Combustion, Fuels, and Emissions","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131244815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Humidity and Fuel Hydrogen Content on Ultrafine Non-Volatile Particulate Matter Formation in RQL Gas Turbine Technology","authors":"A. Crayford, P. Bowen, Eliot F. Durand, D. Pugh, Y. Sevcenco, Mark P. Johnson","doi":"10.1115/GT2020-15168","DOIUrl":"https://doi.org/10.1115/GT2020-15168","url":null,"abstract":"\u0000 To address the known Local Air Quality impacts of ultrafine combustion derived soot, the International Civil Aviation Organisation (ICAO) have recently adopted a non-volatile Particulate Matter (nvPM) regulation in addition to those of NOx, UHC’s and CO for civil aviation gas turbines. Increased water humidity is known to reduce the formation of NOx in flames through localised temperature reduction, however its impact on emitted nvPM is to date not clearly understood. To address this knowledge gap, nvPM formation mechanisms were assessed empirically at increasing water loadings both at atmospheric pressure — in a RQL representative optical combustor fuelled with Jet A and alternative fuel blends — and during a full-scale Rolls-Royce aero-derivative Gas Turbine test fuelled on Diesel.\u0000 In line with previous studies, in the RQL combustor rig it was observed that increased hydrogen content in the test fuel — associated with a 100% Gas-To-Liquid (GTL) derived aviation kerosene with low aromatic content (0.05%) — reduced nvPM number concentrations by an order of magnitude compared to a baseline Jet A-1 fuel with representative aromatic content (24.24%). For all fuels tested it was also observed that an elevated water loading in the primary combustion zone (≤ 0.05 kg /kg of dry air), representative of maximum global humidity levels, resulted in reductions of both nvPM number and mass concentrations of 40% and 60% respectively. During a full-scale Rolls-Royce gas turbine study similar trends were observed, with an 85% reduction in measured nvPM mass whilst water was injected into the combustor at flow rates 25% higher than the diesel fuel flow.\u0000 The nvPM reductions in both experiments are significantly larger than can be explained by water dilution effects alone, with less impact noted for fuels with higher hydrogen content. This suggests the reduction may be in part due to chemistry. Preliminary chemical kinetic investigations were undertaken using CHEMKIN-PRO and suggest that the soot reduction mechanism is potentially via a reduction in PAH formation within the flame zone. However, further analysis is required to validate if this mechanism is dominated by in-flame OH reduction mechanisms or influenced significantly by other factors associated with water dilution and reduced flame temperatures.","PeriodicalId":311793,"journal":{"name":"Volume 4A: Combustion, Fuels, and Emissions","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117309029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of Atomization Behaviors of Liquid Monopropellants in Pintle Injectors","authors":"Jacob Gamertsfelder, P. Khare, L. Bravo","doi":"10.1115/GT2020-15047","DOIUrl":"https://doi.org/10.1115/GT2020-15047","url":null,"abstract":"\u0000 This research effort focuses on the atomization physics of liquid monopropellents emanating from a pintle-type injector at high-pressure conditions. These injectors are used extensively in liquid-fueled propulsion systems, such as rockets and diesel engines, and undersea vehicles and munitions. While extensive research has been conducted in the past on bipropellant fuel injection and atomization, limited literature exists on the understanding of atomization processes of monopropellant fuels in a pintle injector configuration for viscous fluids at elevated pressures. Therefore, in the current work, injection and subsequent atomization processes of a liquid monopropellant fuel are investigated as it is injected through a pintle injector in a stagnant environment using direct numerical simulations. The pintle injector consists of an annulus with an outer diameter twice the size of the inner diameter, and center pintle that throttles the fuel out of the injector. The theoretical and mathematical formulation to investigate these two-phase problems is based on the three-dimensional incompressible Navier-Stokes equations with surface tension. A critical issue is the treatment of multi-scale liquid-liquid and gas-liquid interfaces, therefore, a state-of-the-art, high resolution, volume-of-fluid (VOF) interface capturing method is adopted to resolve the interfacial evolution. Surface tension is accommodated as a Dirac delta distribution function on the interface. The theoretical formulation outlined above is solved numerically using a finite volume method augmented by an adaptive mesh refinement (AMR) technique, based on an octree spatial discretization to improve the solution accuracy and efficiency. As a first step, for model validation, we simulate water injection in the aforementioned geometry at a flowrate of 44.4 g/s in a stagnant chamber at 1 atm and room temperature conditions. Comparison of our results with experimentally measured sauter mean diameter and spray angle shows excellent agreement — both quantities are within 4.2% of the measured quantities. Next, Otto fuel II injection and atomization are studied to elucidate the atomization characteristics of the fuel in a pintle injector. The dynamic viscosity of the representative liquid monopropellant, Otto fuel II is 0.0044 Pa-s, density is 1232 kg/m3, and the surface tension at the gas-liquid interface is 0.03445 N/m. The operating conditions consist of p = 106.2 bar, T = 300 K, and inlet velocity u = 3.34 m/s, corresponding to a density ratio of 10, dynamic viscosity ratio of 212 and Weber number of 20 (based on gas density). Results indicate that a radially growing hollow cone spray film attached at the injector exit is formed. Instability waves are formed on the outer and inner surfaces of the cone that facilitates breakup. Once droplets are completely separated from the cone, they are convected to recirculation zones, thus interacting with the hollow cone and amplifying the instability wa","PeriodicalId":311793,"journal":{"name":"Volume 4A: Combustion, Fuels, and Emissions","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128312289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Numerical Study on the Effects of Acoustic Forcing on Fuel Spray Dynamics in Gas Turbines","authors":"N. Treleaven, A. Garmory, G. Page","doi":"10.1115/GT2020-14238","DOIUrl":"https://doi.org/10.1115/GT2020-14238","url":null,"abstract":"\u0000 In the case of aircraft engines, the fuel is injected as a liquid spray which may play a role in thermoacoustic instabilities through creating changes to the mixture fraction inside the combustion chamber. This study uses two-phase incompressible non-reacting large eddy simulation with Lagrangian particle tracking to show how spray droplets of different sizes can be affected by large scale hydrodynamic structures and acoustic forcing. The forcing is applied at the inlets of a truncated computational domain that only includes the geometry downstream of the fuel injector using the newly developed PODFS (proper orthogonal decomposition Fourier series) method. The PODFS is a model that can reproduce the effects of acoustic forcing by extracting planes of data from an auxiliary acoustically forced compressible unsteady Reynolds averaged Navier-Stokes simulation. A proper orthogonal decomposition analysis shows that fuel droplets of a typical size seen in jet engines are more sensitive to acoustic and hydrodynamic structures than droplets with an order of magnitude larger or smaller diameter, consistent with their Stokes number. Phase and azimuthally averaged results show that fluctuations of the spray mixture fraction represented by large droplets affect the total spray mixture fraction much more than fluctuations of the small droplets. An additional intermittent spray dispersion mechanism was identified that is due to intermittent vorticity being generated between the two outer injector flow passages. An injector design modification has been suggested that will reduce the prevalence of this mechanism.","PeriodicalId":311793,"journal":{"name":"Volume 4A: Combustion, Fuels, and Emissions","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128706475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laminar Flame Speeds of Oxy-Methane Flames With CO2 Dilution at Elevated Pressures","authors":"M. Turner, W. Kulatilaka, E. Petersen","doi":"10.1115/GT2020-14441","DOIUrl":"https://doi.org/10.1115/GT2020-14441","url":null,"abstract":"\u0000 Spherically expanding, laminar flame experiments have been conducted for oxy-methane mixtures diluted in CO2. Test conditions consisted of pressures of 5 atm and 10 atm, an ambient initial temperature of 298 K, and a full range of equivalence ratios from lean to rich. Schlieren imaging was used to image the flames. The mixtures tested in this study contained helium for the purpose of increasing the Lewis number to suppress onset of thermal-diffusive instabilities. Flame speeds ranged from 24.3 to 30.4 cm/s at 5 atm initial pressure and from 17.9 to 22.6 cm/s at 10 atm, resulting in an approximately 26% decrease in flame speed across all tested equivalence ratios as a result of the doubling in initial pressure. Predicted flame speeds from AramcoMech2.0 tended to be higher than the experimental data by 3% at 5 atm initial pressure and 8% at 10 atm initial pressure, indicating that the performance of the mechanism is quite good for this mixture, but diminishes slightly as pressure increases.","PeriodicalId":311793,"journal":{"name":"Volume 4A: Combustion, Fuels, and Emissions","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129986980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flame Transfer Functions and Dynamics of a Closely Confined Premixed Bluff Body Stabilised Flame With Swirl","authors":"Håkon T. Nygård, N. Worth","doi":"10.1115/gt2020-15176","DOIUrl":"https://doi.org/10.1115/gt2020-15176","url":null,"abstract":"\u0000 The Flame Transfer Function (FTF) and flame dynamics of a single, highly swirled, closely confined, premixed flame is studied over a wide range of operating conditions at a fixed perturbation level at the dump plane. The equivalence ratio and bulk velocity are varied in order to examine the important ratio of flame height to velocity in scaling the flame response function. The enclosure geometry is kept constant, and therefore due to the close confinement and varying flame height, strong flame-wall interactions are present for some operating conditions. The effect of these interactions on the FTF due to changes in the “relative” or “effective confinement” of the flame can therefore be studied. When the equivalence ratio is sufficiently high, and therefore the effective confinement sufficiently small, modulations, or dips, in the gain and phase of the FTF are observed, due to interference of the perturbations created at the swirler and at the dump plane. Due to the small length scales and relatively high velocities in the current configuration, the dip is at a high frequency and spans a wide range of frequencies compared to similar studies which have previously identified similar phenomena. It is also observed that when the equivalence ratio was decreased, increasing the effective confinement, a critical point is reached where the modulations are suppressed. This is linked to a temporal shift in the heat release rate at the downstream location where the flame impinges on the combustion chamber walls during the oscillation cycle. The shift causes a decrease in the expected level of interference, demonstrating that the effective confinement is an important parameter to consider for the nature of the FTF response. Additionally, a Distributed Time Lag (DTL) model with two distinct time lags, capturing the swirler perturbations and the perturbations at the inlet, is successfully applied to the FTFs. The model provides a simple way to accurately capture the two dominant time scales in the problem without the need of prior knowledge of the cause of the perturbations, and a simple expression to recreate the complex valued FTF. In addition the model also provides insight into the time scales of the problem, demonstrating in the current work that time scales recovered from the DTL analysis are offset from simple Strouhal number scaling, due to the effects of increasing effective confinement.","PeriodicalId":311793,"journal":{"name":"Volume 4A: Combustion, Fuels, and Emissions","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132570235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}