Experimental and Numerical Studies of the Aerodynamics of Stationary Two-Shaft Gas Turbine Exhaust System

In this study, the aerodynamic performance of the exhaust system of a two-shaft gas turbine was investigated experimentally and numerically. The investigation focused on the system “Turbine Stage-Diffuser—Collector Box” and aimed to examine the impact of inlet conditions and geometry particularities...

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Main Authors: Viktor Chernikov, Elena Semakina
Format: Article
Language:English
Published: MDPI AG 2023-04-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/16/9/3671
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author Viktor Chernikov
Elena Semakina
author_facet Viktor Chernikov
Elena Semakina
author_sort Viktor Chernikov
collection DOAJ
description In this study, the aerodynamic performance of the exhaust system of a two-shaft gas turbine was investigated experimentally and numerically. The investigation focused on the system “Turbine Stage-Diffuser—Collector Box” and aimed to examine the impact of inlet conditions and geometry particularities on the efficiency of the exhaust system. The experiments were conducted on the Test Ring ET4 (Experimental Turbine-4) at the Peter the Great St.Petersburg Polytechnic University, which was equipped with a special diversion channel to examine the non-axisymmetric outlet of the exhaust duct. The collector box was designed to rotate by 180 degrees around the turbine axis to investigate its impact on the system’s performance. Flow traversing parameters were measured with the five-channel pneumatic pressure probes, and numerical simulations were performed with CFX 15.0. The RANS (Reynolds-averaged Navier–Stokes) equations were closed with the SST (k-ω) turbulence model (Shear Stress Transport model). The study concluded that the RANS SST model predicts the flow in the diffuser before the struts accurately. However, downstream the struts, the CFD (Computer fluid dynamic) results over-predicted the exhaust diffuser pressure recovery coefficient by 14% due to the complex vortex structure of the turbulent flow, which the Averaged Navier–Stokes equations did not resolve. The study highlights the importance of considering the last stage of the turbine, diffuser, and collector box as an integrated system when investigating the aerodynamics of exhaust ducts. The study also emphasizes the impact of geometry and inlet conditions on the exhaust diffuser’s performance and efficiency. The results of this study can be used to optimize the design of the exhaust system of two-shaft gas turbines and improve their thermal efficiency. The integrated approach of combining experimental and numerical methods can provide a detailed and reliable flow picture and can be used for future research in this area.
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spelling doaj.art-832039729af941c3b8466143a13473832023-11-17T22:50:10ZengMDPI AGEnergies1996-10732023-04-01169367110.3390/en16093671Experimental and Numerical Studies of the Aerodynamics of Stationary Two-Shaft Gas Turbine Exhaust SystemViktor Chernikov0Elena Semakina1Institute of Energy, Peter The Great Saint-Petersburg Polytechnic University, 195251 St. Petersburg, RussiaInstitute of Energy, Peter The Great Saint-Petersburg Polytechnic University, 195251 St. Petersburg, RussiaIn this study, the aerodynamic performance of the exhaust system of a two-shaft gas turbine was investigated experimentally and numerically. The investigation focused on the system “Turbine Stage-Diffuser—Collector Box” and aimed to examine the impact of inlet conditions and geometry particularities on the efficiency of the exhaust system. The experiments were conducted on the Test Ring ET4 (Experimental Turbine-4) at the Peter the Great St.Petersburg Polytechnic University, which was equipped with a special diversion channel to examine the non-axisymmetric outlet of the exhaust duct. The collector box was designed to rotate by 180 degrees around the turbine axis to investigate its impact on the system’s performance. Flow traversing parameters were measured with the five-channel pneumatic pressure probes, and numerical simulations were performed with CFX 15.0. The RANS (Reynolds-averaged Navier–Stokes) equations were closed with the SST (k-ω) turbulence model (Shear Stress Transport model). The study concluded that the RANS SST model predicts the flow in the diffuser before the struts accurately. However, downstream the struts, the CFD (Computer fluid dynamic) results over-predicted the exhaust diffuser pressure recovery coefficient by 14% due to the complex vortex structure of the turbulent flow, which the Averaged Navier–Stokes equations did not resolve. The study highlights the importance of considering the last stage of the turbine, diffuser, and collector box as an integrated system when investigating the aerodynamics of exhaust ducts. The study also emphasizes the impact of geometry and inlet conditions on the exhaust diffuser’s performance and efficiency. The results of this study can be used to optimize the design of the exhaust system of two-shaft gas turbines and improve their thermal efficiency. The integrated approach of combining experimental and numerical methods can provide a detailed and reliable flow picture and can be used for future research in this area.https://www.mdpi.com/1996-1073/16/9/3671exhaust ductaerodynamic integral characteristics3D flow structureaerodynamic experimentnumerical simulations
spellingShingle Viktor Chernikov
Elena Semakina
Experimental and Numerical Studies of the Aerodynamics of Stationary Two-Shaft Gas Turbine Exhaust System
Energies
exhaust duct
aerodynamic integral characteristics
3D flow structure
aerodynamic experiment
numerical simulations
title Experimental and Numerical Studies of the Aerodynamics of Stationary Two-Shaft Gas Turbine Exhaust System
title_full Experimental and Numerical Studies of the Aerodynamics of Stationary Two-Shaft Gas Turbine Exhaust System
title_fullStr Experimental and Numerical Studies of the Aerodynamics of Stationary Two-Shaft Gas Turbine Exhaust System
title_full_unstemmed Experimental and Numerical Studies of the Aerodynamics of Stationary Two-Shaft Gas Turbine Exhaust System
title_short Experimental and Numerical Studies of the Aerodynamics of Stationary Two-Shaft Gas Turbine Exhaust System
title_sort experimental and numerical studies of the aerodynamics of stationary two shaft gas turbine exhaust system
topic exhaust duct
aerodynamic integral characteristics
3D flow structure
aerodynamic experiment
numerical simulations
url https://www.mdpi.com/1996-1073/16/9/3671
work_keys_str_mv AT viktorchernikov experimentalandnumericalstudiesoftheaerodynamicsofstationarytwoshaftgasturbineexhaustsystem
AT elenasemakina experimentalandnumericalstudiesoftheaerodynamicsofstationarytwoshaftgasturbineexhaustsystem