scholarly journals Estimation of the turbulent Schmidt number in a model gas turbine combustor

2021 ◽  
Vol 2057 (1) ◽  
pp. 012084
Author(s):  
A G Savitskii ◽  
D K Sharaborin ◽  
A S Lobasov ◽  
V M Dulin

Abstract This article presents the estimation of turbulent Schmidt number in a model gas turbine combustor. Different gases are used as the model fuel while maintaining the mass flow rate. The simplest closure models for Reynolds stress and turbulent flux are considered. The anisotropy of turbulent viscosity is demonstrated.

Author(s):  
J. Brouwer ◽  
B. A. Ault ◽  
J. E. Bobrow ◽  
G. S. Samuelsen

Closed-loop feedback control, developed in a axisymmetric can combustor, is demonstrated in a model can combustor with discrete wall jets. The study represents the initial steps toward the application of feedback control technology to practical gas turbine combustion systems. For the present application, the radiative flux from soot particulate is used as an indication of combustor performance, and nozzle atomizing air is selected as the input parameter. A measurement of radiative flux at the exit plane of the combustor is conveyed to a control computer which invokes an optimization algorithm to determine changes in the dome region necessary to minimize the radiative flux from soot. The results demonstrate the utility and potential of active control for maintaining optimal performance in real-time.


Author(s):  
Oanh Nguyen ◽  
Scott Samuelsen

In view of increasingly stringent NOx emissions regulations on stationary gas turbines, lean combustion offers an attractive option to reduce reaction temperatures and thereby decrease NOx production. Under lean operation, however, the reaction is vulnerable to blowout. It is herein postulated that pilot hydrogen dopant injection, discretely located, can enhance the lean blowout performance without sacrificing overall performance. The present study addresses this hypothesis in a research combustor assembly, operated at atmospheric pressure, and fired on natural gas using rapid mixing injection, typical of commercial units. Five hydrogen injector scenarios are investigated. The results show that (1) pilot hydrogen dopant injection, discretely located, leads to improved lean blowout performance and (2) the location of discrete injection has a significant impact on the effectiveness of the doping strategy.


Author(s):  
C. A. Ferguson ◽  
A. M. Mellor

Measurements have been made of the normal component of the radiative heat flux to the wall of a model gas turbine combustor with and without a mirrored background. Measurements have also been made of the centerline soot concentration. The data show that the heat flux correlated with the soot concentration but not universally, since JET A fuel yielded a different curve 1han DIESEL fuel. A theoretical analysis of the heat flux from a soot suspension was formulated. A criterion was established for the use of a small particle analysis. Finally, it is shown that there is no correspondence between theory and these experiments. It is speculated that turbulent fluctuations need to be modeled.


Author(s):  
Rongxiao Dong ◽  
Qingchun Lei ◽  
Yeqing Chi ◽  
Qun Zhang ◽  
Wei Fan

Abstract Time-resolved volumetric measurements (4D measurements) were performed to study the heat release rate characteristics in a model gas turbine combustor at 10 kHz. For this purpose, a high-speed camera combined with an image intensifier and a set of customized fiber probes were employed to continuously capture the CH* chemiluminescence signals from nine different viewing angles. Based on the measurements, the computed tomography program was performed to reconstruct the shot-to-shot 3D distributions of the CH* signals. Specific focuses have been made to demonstrate the capabilities of the current tomographic technique in applications of a realistic combustor, in which the full optical access was usually not available for every viewing angle. The results showed that the 3D reconstruction can successfully retrieval the flame edge contours rather than the signal intensity. The flame surface area was then calculated based on the reconstructed flame edge contours and used to infer the heat release rate. The fluctuation of global/local flame surface area indicated that there existed distinct difference between the global instability and local instabilities at various locations in the non-symmetric combustor. The global instability appears to be an integration of those local instabilities.


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