Large Eddy Simulation of the Influences of the Pilot-Stage Structure on the Flow Characteristics in a Centrally Staged High-Temperature-Rise Combustor
Centrally staged combustion technique is often used in the military high-temperature-rise combustor. The pilot-stage structure affects the flow characteristics in the centrally staged combustor, which further affects the performance of ignition, combustion, and emission of military aero-engines. In...
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MDPI AG
2022-12-01
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author | Ge Hu Qiongyao Qin Wu Jin Jianzhong Li |
author_facet | Ge Hu Qiongyao Qin Wu Jin Jianzhong Li |
author_sort | Ge Hu |
collection | DOAJ |
description | Centrally staged combustion technique is often used in the military high-temperature-rise combustor. The pilot-stage structure affects the flow characteristics in the centrally staged combustor, which further affects the performance of ignition, combustion, and emission of military aero-engines. In order to increase the flow capacity of the swirler, the swirler with a non-rotating channel structure was designed. In this work, the influences of the pilot-stage structure on the flow characteristics in the centrally staged high-temperature-rise combustor are investigated. The flow fields of combustors with different pilot-stage swirl numbers (0.44, 0.60, and 0.71) are analyzed by large eddy simulation (LES). The results demonstrate that the primary recirculation zone (PRZ) becomes gradually longer and wider as the pilot-stage swirl number increases. In the combustors with three different pilot-stage structures, the precessing vortex core (PVC) was formed near the shear layer at the outlet of the pilot stage. The PVC frequency decreased from 1670 Hz to 1425 Hz and 1400 Hz with the increase of the pilot-stage swirl number from 0.44 to 0.60 and 0.71, respectively, and the breakdown position of the PVC shifted forward. The proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD) methods are used to analyze the dynamic flow fields. It was observed that the corresponding frequency of the main pulsation structure decreased, and the flow instability was aggravated with the increase of the pilot-stage swirl number. The results deepen the understanding of the influences of the pilot-stage structure on the flow characteristics in the centrally staged high-temperature-rise combustor. |
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spelling | doaj.art-eb49d9c375b04df0a2a00462a5091f1a2023-11-24T12:37:54ZengMDPI AGAerospace2226-43102022-12-0191278210.3390/aerospace9120782Large Eddy Simulation of the Influences of the Pilot-Stage Structure on the Flow Characteristics in a Centrally Staged High-Temperature-Rise CombustorGe Hu0Qiongyao Qin1Wu Jin2Jianzhong Li3Key Laboratory of Aero-Engine Thermal Environment and Structure, Ministry of Industry and Information Technology, Nanjing University of Aeronautics and Astronautics, 29 Yudao St., Nanjing 210016, ChinaKey Laboratory of Aero-Engine Thermal Environment and Structure, Ministry of Industry and Information Technology, Nanjing University of Aeronautics and Astronautics, 29 Yudao St., Nanjing 210016, ChinaKey Laboratory of Aero-Engine Thermal Environment and Structure, Ministry of Industry and Information Technology, Nanjing University of Aeronautics and Astronautics, 29 Yudao St., Nanjing 210016, ChinaKey Laboratory of Aero-Engine Thermal Environment and Structure, Ministry of Industry and Information Technology, Nanjing University of Aeronautics and Astronautics, 29 Yudao St., Nanjing 210016, ChinaCentrally staged combustion technique is often used in the military high-temperature-rise combustor. The pilot-stage structure affects the flow characteristics in the centrally staged combustor, which further affects the performance of ignition, combustion, and emission of military aero-engines. In order to increase the flow capacity of the swirler, the swirler with a non-rotating channel structure was designed. In this work, the influences of the pilot-stage structure on the flow characteristics in the centrally staged high-temperature-rise combustor are investigated. The flow fields of combustors with different pilot-stage swirl numbers (0.44, 0.60, and 0.71) are analyzed by large eddy simulation (LES). The results demonstrate that the primary recirculation zone (PRZ) becomes gradually longer and wider as the pilot-stage swirl number increases. In the combustors with three different pilot-stage structures, the precessing vortex core (PVC) was formed near the shear layer at the outlet of the pilot stage. The PVC frequency decreased from 1670 Hz to 1425 Hz and 1400 Hz with the increase of the pilot-stage swirl number from 0.44 to 0.60 and 0.71, respectively, and the breakdown position of the PVC shifted forward. The proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD) methods are used to analyze the dynamic flow fields. It was observed that the corresponding frequency of the main pulsation structure decreased, and the flow instability was aggravated with the increase of the pilot-stage swirl number. The results deepen the understanding of the influences of the pilot-stage structure on the flow characteristics in the centrally staged high-temperature-rise combustor.https://www.mdpi.com/2226-4310/9/12/782centrally staged high-temperature-rise combustorlarge eddy simulationunsteady characteristicsprecessing vortex coremode decomposition |
spellingShingle | Ge Hu Qiongyao Qin Wu Jin Jianzhong Li Large Eddy Simulation of the Influences of the Pilot-Stage Structure on the Flow Characteristics in a Centrally Staged High-Temperature-Rise Combustor Aerospace centrally staged high-temperature-rise combustor large eddy simulation unsteady characteristics precessing vortex core mode decomposition |
title | Large Eddy Simulation of the Influences of the Pilot-Stage Structure on the Flow Characteristics in a Centrally Staged High-Temperature-Rise Combustor |
title_full | Large Eddy Simulation of the Influences of the Pilot-Stage Structure on the Flow Characteristics in a Centrally Staged High-Temperature-Rise Combustor |
title_fullStr | Large Eddy Simulation of the Influences of the Pilot-Stage Structure on the Flow Characteristics in a Centrally Staged High-Temperature-Rise Combustor |
title_full_unstemmed | Large Eddy Simulation of the Influences of the Pilot-Stage Structure on the Flow Characteristics in a Centrally Staged High-Temperature-Rise Combustor |
title_short | Large Eddy Simulation of the Influences of the Pilot-Stage Structure on the Flow Characteristics in a Centrally Staged High-Temperature-Rise Combustor |
title_sort | large eddy simulation of the influences of the pilot stage structure on the flow characteristics in a centrally staged high temperature rise combustor |
topic | centrally staged high-temperature-rise combustor large eddy simulation unsteady characteristics precessing vortex core mode decomposition |
url | https://www.mdpi.com/2226-4310/9/12/782 |
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