Impact of the Inflow Conditions on the Heavy-Duty Gas Turbine Exhaust Diffusers Performance

Vassiliev, V. V.; Irmisch, Stefan; Abdel-Wahab, Samer; Granovskiy, Andrey

doi:10.1115/gt2010-22840

Cited by 5 publications

(2 citation statements)

References 13 publications

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“…The results showed that for the given diffuser configuration, the pressure recovery of volute diffusers is basically independent from the inlet Mach number, but varies considerably with the inlet swirl, and the reason for the dependency is related to the flow separation at the struts, caused by the different incidence angles. The subsequent investigations of Vassiliev et al 14 and Dong et al 15 have further indicated that the nonuniform inlet pressure distribution, as compared to a uniform one, can lead to better volute diffuser performances, and the moderate residual swirl can improve the volute aerodynamic performance significantly.…”

Section: Effect Of Turbine Exit Conditions Simulated On the Nonaxisymmetric Exhaust Volutementioning

confidence: 98%

Advances in coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics for turbomachinery

Gao

Tao

Huo

et al. 2020

Proceedings of the Institution of Mechanical Engineers, Part G:

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Marine, industrial, turboprop and turboshaft gas turbine engines use nonaxisymmetric exhaust volutes for flow diffusion and pressure recovery. These processes result in a three-dimensional complex turbulent flow in the exhaust volute. The flows in the axial turbine and nonaxisymmetric exhaust volute are closely coupled and inherently unsteady, and they have a great influence on the turbine and exhaust aerodynamic characteristics. Therefore, it is very necessary to carry out research on coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics, so as to provide reference for the high-efficiency turbine-volute designs. This paper summarizes and analyzes the recent advances in the field of coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics for turbomachinery. This review covers the following topics that are important for turbine and volute coupled designs: (1) flow and loss characteristics of nonaxisymmetric exhaust volutes, (2) flow interactions between axial turbine and nonaxisymmetric exhaust volute, (3) improvement of turbine and volute performance within spatial limitations and (4) research methods of coupled turbine and exhaust volute aerodynamics. The emphasis is placed on the turbine-volute interactions and performance improvement. We also present our own insights regarding the current research trends and the prospects for future developments.

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Section: Effect Of Turbine Exit Conditions Simulated On the Nonaxisymmetric Exhaust Volutementioning

confidence: 98%

Advances in coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics for turbomachinery

Gao

Tao

Huo

et al. 2020

Proceedings of the Institution of Mechanical Engineers, Part G:

View full text Add to dashboard Cite

show abstract

“…[18][19][20][21][22] These investigations include the effect of Mach and Reynolds number, total pressure and temperature distribution, flow angle, and turbulence. The systematic review of all these effects is provided in Vassiliev et al 23 From their studies, it is known that the performance of the diffusers is influenced by the inflow conditions.…”

Section: Introductionmentioning

confidence: 99%

Aerodynamic performance analysis and optimization of a turbine duct with low degree of partial admission

Sui

Zhao

Sun

et al. 2017

Proceedings of the Institution of Mechanical Engineers, Part G:

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A partial admission turbine duct with outlet-to-inlet area ratio greater than unity can increase the admission degree of the downstream turbine stage and, thus improve the performance of a multistage turbine with a low partial admission degree. However, the upstream flow structures of ducts, such as secondary flow, especially the circumferential nonuniformities originating from the effect of the partial admission, make the flow in ducts complex. The complexity of the flow has a negative impact on the performance of ducts. In the present investigation, numerical study of the flow behavior within ducts is done to evaluate the effect of the partial admission on the performance of the ducts. The study is carried out with regard to two cases, i.e. which are with the same duct geometry but are at different working conditions to highlight the impact of partial admission on the performance of ducts. Case 1 is used as baseline. It is designed based on circumferential mass-averaged flow conditions at ducts inlet. It causes the circumferential nonuniformities originating from the partial admission to have no impact on the performance of case 1. Case 2, which considers partial admission, is compared with case 1 to know the impact of the partial admission on the performance of ducts, and to give guidelines to design a duct for the partial admission turbines. Since the duct inlet conditions is a result of the interaction between partial admission turbine and duct, a straightforward way to consider the effect of the partial admission is to simulate the flows in ducts and upstream turbines contemporaneously. Comparative results indicate that the mixing of main flow in the admitted channel and the windage fluid from the unadmitted channel occurs at the duct inlet close to the duct circumferential wall. The adverse pressure gradient of case 2 in that region becomes larger than that of case 1. As a result, the flow separates at that region deteriorating the performance of ducts. Based on the simulation results of the previous cases, case 2's circumferential wall surface, which is along the gas swirling direction is shrunk to accelerate the flow and, thereby, overcome the adverse pressure gradient imposed by the effect of the partial admission. The results show that the separation is restrained and the decrease in total pressure loss is 52.9%.

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Quantitative Expression of Outlet Deviation Angle of Turbomachine Stator Based on Equivalent Moment of Momentum Principle

Wang

Wei

et al. 2017

MATEC Web Conf.

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Impact of the Inflow Conditions on the Heavy-Duty Gas Turbine Exhaust Diffusers Performance

Cited by 5 publications

References 13 publications

Advances in coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics for turbomachinery

Advances in coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics for turbomachinery

Aerodynamic performance analysis and optimization of a turbine duct with low degree of partial admission

Quantitative Expression of Outlet Deviation Angle of Turbomachine Stator Based on Equivalent Moment of Momentum Principle

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