Design and Validation of a Novel Test-Rig for RQL Flame Dynamics Studies

March, Martin; Renner, Julian; Hirsch, Christoph; Sattelmayer, Thomas

doi:10.1115/gt2021-58602

Cited by 2 publications

(3 citation statements)

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“…The test rig is operated at atmospheric pressure in a thermal power range of 45 − 80 .1em kW. Its design is discussed by March et al 21 and more details and additional information on the current configuration can be found in Renner et al 10 . Natural gas is used as fuel in the first stage.…”

Section: Methodsmentioning

confidence: 99%

Flame Transfer Functions of the Lean Burnout Zone of an RQL Combustion Chamber - Dynamic Response to Primary Zone and Mixing Port Velocity Fluctuations

Renner

March

et al. 2023

International Journal of Spray and Combustion Dynamics

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This article describes an experimental investigation of thermoacoustic flame transfer functions of the lean burnout zone of an rich–quench–lean combustion chamber. With spatial separation of the rich primary from the lean secondary dilution zone, the latter is independently examined. The multi-microphone-method was employed to characterize the combustor acoustic velocity response to acoustic forcing coming from the primary zone and the mixing ports. The lean secondary zone is then treated as a pure acoustic 3-port network element connected to a 2-port Rankine-Hugoniot flame element. Focusing only on heat release fluctuations due to velocity fluctuations, the former are described by two linear superimposed flame transfer functions as a function of the velocity fluctuations coming from the primary zone and the mixing ports, respectively. Based on a non-reacting and a reacting measurement the two flame transfer functions could be extracted from the experimental data. Within this research, flame transfer functions from the new acoustical approach are presented and compared with ones measured using chemiluminescence and a photomultiplier tube. It is found that the inverse diffusion flame in the burnout zone reacts to velocity fluctuations from the primary zone in the low frequency range and a clear low pass behavior is observed. The mixing port velocity fluctuations create a more broadband response. In the presented cases, the flame transfer functions calculated from chemiluminescence match those from the acoustic method very well.

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Section: Methodsmentioning

confidence: 99%

Flame Transfer Functions of the Lean Burnout Zone of an RQL Combustion Chamber - Dynamic Response to Primary Zone and Mixing Port Velocity Fluctuations

Renner

March

et al. 2023

International Journal of Spray and Combustion Dynamics

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“…The current setup is shown in Figure 3 and the design parameters are listed below in Table 1. More information about the design of the mixing holes can be found in March et al 9 . For the measurements presented in this paper, a single row setup consisting of three opposed mixing holes on each side was chosen.…”

Section: Methodsmentioning

confidence: 99%

“…The novel test rig presented in the authors previous paper 9 was designed to measure and characterize the flame dynamics of the lean secondary zone in an RQL combustion chamber. Separating the rich primary zone from the lean mixing zone allows an independent investigation of the lean secondary zone and its contribution to the whole acoustic system.…”

Section: Introductionmentioning

confidence: 99%

Flame dynamics in the lean burnout zone of an RQL combustion chamber - response to primary zone velocity fluctuations

Renner

March

Hirsch

et al. 2022

International Journal of Spray and Combustion Dynamics

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This study focuses on elucidating the flame dynamics of the lean burnout zone of an Rich-Quench-Lean (RQL) combustion chamber. With a new experimental approach of spatially separating the rich primary zone from the lean burnout zone, the latter can be investigated independently in terms of velocity fluctuations. Acoustically stiff mixing air ports in the lean burnout zone are ensured to prevent any acoustic interaction of the primary crossflow with the secondary mixing air jets. Therefore, defined boundary conditions at the mixing air inlets are used. Resulting no thermoacoustic interaction and additional flame dynamics are generated. In this specific case the lean burnout zone can be treated as a 2-port system allowing the application of existing evaluation methods e.g. acoustic determination of flame-transfer-functions (FTF) from the Rankine-Hugoniot (RH) equation or quantification of the heat release with chemiluminescence in combination with the Multi-Microphone-Method (MMM). Within this research, FTFs acoustically measured with the RH approach are presented and serve as a baseline for comparison with ones measured via a photomultiplier tube (PMT). It is found that the inverse diffusion flame in the burnout zone only reacts to fluctuations in the low frequency range and a clear low pass behavior is observed. The FTFs, calculated via the PMT match those from RH very well. Amplitude weighted phase images, recorded with a high-speed camera setup, visualize changes during excitation which complement and confirm the findings from the FTF.

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Design and Validation of a Novel Test-Rig for RQL Flame Dynamics Studies

Cited by 2 publications

References 0 publications

Flame Transfer Functions of the Lean Burnout Zone of an RQL Combustion Chamber - Dynamic Response to Primary Zone and Mixing Port Velocity Fluctuations

Flame Transfer Functions of the Lean Burnout Zone of an RQL Combustion Chamber - Dynamic Response to Primary Zone and Mixing Port Velocity Fluctuations

Flame dynamics in the lean burnout zone of an RQL combustion chamber - response to primary zone velocity fluctuations

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