CFD Modeling of a Gas Turbine Combustor From Compressor Exit to Turbine Inlet

1999 ◽  
Vol 121 (1) ◽  
pp. 89-95 ◽  
Author(s):  
D. S. Crocker ◽  
D. Nickolaus ◽  
C. E. Smith

Gas turbine combustor CFD modeling has become an important combustor design tool in the past few years, but CFD models are generally limited to the flow field inside the combustor liner or the diffuser/combustor annulus region. Although strongly coupled in reality, the two regions have rarely been coupled in CFD modeling. A CFD calculation for a full model combustor from compressor diffuser exit to turbine inlet is described. The coupled model accomplishes the following two main objectives: (1) implicit description of flow splits and flow conditions for openings into the combustor liner, and (2) prediction of liner wall temperatures. Conjugate heat transfer with nonluminous gas radiation (appropriate for lean, low emission combustors) is utilized to predict wall temperatures compared to the conventional approach of predicting only near wall gas temperatures. Remaining difficult issues such as generating the grid, modeling Swirled vane passages, and modeling effusion cooling are also discussed.

Author(s):  
D. Scott Crocker ◽  
Dan Nickolaus ◽  
Clifford E. Smith

Gas turbine combustor CFD modeling has become an important combustor design tool in the past few years, but CFD models are generally limited to the flow field inside the combustor liner or the diffuser/combustor annulus region. Although strongly coupled in reality, the two regions have rarely been coupled in CFD modeling. A CFD calculation for a full model combustor from compressor diffuser exit to turbine inlet is described. The coupled model accomplishes two main objectives: 1) implicit description of flow splits and flow conditions for openings into the combustor liner, and 2) prediction of liner wall temperatures. Conjugate heat transfer with nonluminous gas radiation (appropriate for lean, low emission combustors) is utilized to predict wall temperatures compared to the conventional approach of predicting only near wall gas temperatures. Remaining difficult issues such as generating the grid, modeling swirler vane passages, and modeling effusion cooling are also discussed.


Author(s):  
S. James ◽  
M. S. Anand ◽  
B. Sekar

The paper presents an assessment of large eddy simulation (LES) and conventional Reynolds averaged methods (RANS) for predicting aero-engine gas turbine combustor performance. The performance characteristic that is examined in detail is the radial burner outlet temperature (BOT) or fuel-air ratio profile. Several different combustor configurations, with variations in airflows, geometries, hole patterns and operating conditions are analyzed with both LES and RANS methods. It is seen that LES consistently produces a better match to radial profile as compared to RANS. To assess the predictive capability of LES as a design tool, pretest predictions of radial profile for a combustor configuration are also presented. Overall, the work presented indicates that LES is a more accurate tool and can be used with confidence to guide combustor design. This work is the first systematic assessment of LES versus RANS on industry-relevant aero-engine gas turbine combustors.


Author(s):  
Firat Kiyici ◽  
Ahmet Topal ◽  
Ender Hepkaya ◽  
Sinan Inanli

A numerical study, based on experimental work of Inanli et al. [1] is conducted to understand the heat transfer characteristics of film cooled test plates that represent the gas turbine combustor liner cooling system. Film cooling tests are conducted by six different slot geometries and they are scaled-up model of real combustor liner. Three different blowing ratios are applied to six different geometries and surface cooling effectiveness is determined for each test condition by measuring the surface temperature distribution. Effects of geometrical and flow parameters on cooling effectiveness are investigated. In this study, Conjugate Heat Transfer (CHT) simulations are performed with different turbulence models. Effect of the turbulent Prandtl Number is also investigated in terms of heat transfer distribution along the measurement surface. For this purpose, turbulent Prandtl number is calculated with a correlation as a function of local surface temperature gradient and its effect also compared with the constant turbulent Prandtl numbers. Good agreement is obtained with two-layered k–ϵ with modified Turbulent Prandtl number.


Author(s):  
K. O. Smith ◽  
A. Fahme

Three subscale, cylindrical combustors were rig tested on natural gas at typical industrial gas turbine operating conditions. The intent of the testing was to determine the effect of combustor liner cooling on NOx and CO emissions. In order of decreasing liner cooling, a metal louvre-cooled combustor, a metal effusion-cooled combustor, and a backside-cooled ceramic (CFCC) combustor were evaluated. The three combustors were tested using the same lean-premixed fuel injector. Testing showed that reduced liner cooling produced lower CO emissions as reaction quenching near the liner wall was reduced. A reduction in CO emissions allows a reoptimization of the combustor air flow distribution to yield lower NOx emissions.


Meccanica ◽  
2018 ◽  
Vol 53 (9) ◽  
pp. 2257-2271 ◽  
Author(s):  
Ahlem Ben Sik Ali ◽  
Wassim Kriaa ◽  
Hatem Mhiri ◽  
Philippe Bournot

2015 ◽  
Vol 76 (10) ◽  
Author(s):  
Salmi Mohd Yunus ◽  
Mariyam Jameelah Ghazali ◽  
Wan Fathul Hakim W. Zamrib ◽  
Ahmad Afiq Pauzi ◽  
Shuib Husin

A gas turbine combustor liner experienced visible surface damages during its normal operation of 8000 hours. Small amplitudes of vibration during the operation contributed to a surface degradation, mainly wear. A chromium-carbide based hard coating was deposited via plasma spray technique on the outer surface of a combustor liner of a gas turbine engine. It was found that after the operation, the coating hardness had increased more than 30% compared to its minimum initial hardness and reached up to 744 HV particularly in the crossfire tube collar mating areas. Comparison between the coated and the uncoated liners were carried out in order to show how much the wear scars have been minimized throughout the operation under severe temperature of approximately 1, 500°C. It was found that in this study the coating of chromium-carbide is capable to reduce the wear damage due to the work hardening effect of the liner and their mating surfaces.  


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