Numerical study of blade deterioration effects on an industrial gas turbine stage performance and flow field

Aligoodarz, Mohammad Reza; Derakhshan, F Ehsani

doi:10.1177/0957650912471282

Cited by 4 publications

(3 citation statements)

References 11 publications

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“…9. The total pressure loss increases as the roughness increase as a result of blade profile loss growth [9]. In general, the total pressure coefficient of 3 and 6 microns were very similar, especially near the blade mid-span.…”

Section: Figure 8: Rotor Friction Coefficientmentioning

confidence: 86%

“…The efficiency of the turbine is crucial for the gas turbine performance as in some applications a reduction of 1% in the turbine efficiency could result in a 4% reduction in the engine power [7]. Blade surface roughness is one of the design features of the turbines and it can grow considerably (20-150 μm) during the engine operation, especially at high pressure and temperature operating conditions [3,8,9]. A number of methods were used in the literature to examine these effects such as scaling the overall or stage-by-stage performance map of each engine component whilst considering different degradation effects.…”

Section: Introductionmentioning

confidence: 99%

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Assessment of Surface Roughness Effects on Micro Axial Turbines

Gamil

Nikolaidis

Teixeira

et al. 2020

Volume 8: Industrial and Cogeneration; Manufacturing Materials and Metallurgy; Marine; Microturbines, Turbochargers, and Small

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Surface roughness significantly affects the aerodynamics and heat transfer within micro-scale turbine stages. It results in a considerable increment in the blade profile loss and leads consequently to sizeable performance reductions. The provision of low roughness surfaces in micro gas turbine stages presents challenges on account of the small (mm scale) sizes, manufacturing complexity and associated costs. The axial turbine investigated in this study is fitted to Samad Power’s TwinGen domestic micro combined heat and power unit. The micro gas turbine has a compressor pressure ratio of 3, 1200K turbine inlet temperature and a rotational speed of 170,000 rpm. This paper presents a numerical assessment of the effects of varying the surface roughness on the performance and heat transfer of the micro turbine. The surface roughness was uniformly distributed on the NGV and rotor blades. The results showed that increasing the surface roughness from 3 microns to 6, 20, and 100 microns resulted in a reduction in stage total efficiency of 0.8%, 4% and 12% respectively as well as a comparable decrease in output power (0.7%, 3.6%, and 11% respectively). The turbine temperature was also observed to be very sensitive to surface roughness and a temperature increase of some 5% at the rotor hub and over 4% increment in the blade tip surface was observed for 100 microns when compared to the 3 microns surface roughness case. The findings of this paper highlight the adverse effects of the surface roughness on the micro-turbine performance and temperature distribution as well as the importance of careful consideration of wall roughness during the design and manufacturing stages.

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Section: Figure 8: Rotor Friction Coefficientmentioning

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Assessment of Surface Roughness Effects on Micro Axial Turbines

Gamil

Nikolaidis

Teixeira

et al. 2020

Volume 8: Industrial and Cogeneration; Manufacturing Materials and Metallurgy; Marine; Microturbines, Turbochargers, and Small

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“…The errors in the solution related to the grid size should disappear by increasing the mesh resolution. 12 To obtain a sufficient accuracy of the numerical simulation, four grid sizes were used to calculate combustor outlet temperature. As seen in Figure 6, as the number of elements increases, outlet temperature approaches a constant value.…”

Section: Computational Process and Validating The Numerical Modelmentioning

confidence: 99%

Numerical simulation of SGT-600 gas turbine combustor, flow characteristics analysis, and sensitivity measurement with respect to the main fuel holes diameter

Aligoodarz

Soleimanitehrani²,

Karrabi³

et al. 2016

Proceedings of the Institution of Mechanical Engineers, Part G:

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In this article, the combustion chamber of SGT600 gas turbine with 18 Alstom EV burners is numerically simulated to investigate the flow field and combustion properties and analyze the sensitivity of this combustor to diameter of main fuel holes. The three-dimensional simulation is carried out based on the turbulent flame closure model for the two-equation turbulence model, k-ɛ, using OpenFOAM code for SGT600 industrial gas turbine burner. An accurate grid combined of structured and unstructured mesh scheme is employed, which is sufficiently fined in areas of high gradients. Grid independency is investigated and validation of the code established comparing the outlet temperature and flame shape with experimental results. Excellent agreement between numerical analyses and experimental data was observed, so that the difference between calculated and measured outlet temperature was 0.1%. On the basis of reasonable matching of the predicted and experimental results for the combustor, the computational fluid dynamics model enables the prediction of the heat shield and combustor’s wall temperature and critical points of operation. In this article, flow-field and operation condition of this combustor and sensitivity analysis with respect to the main fuel holes diameter are numerically investigated.

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