Mathematical Modeling of an Annular Gas Turbine Combustor

1995 ◽  
Vol 117 (1) ◽  
pp. 94-99 ◽  
Author(s):  
K. Y. Sokolov ◽  
A. G. Tumanovskiy ◽  
M. N. Gutnik ◽  
A. V. Sudarev ◽  
Y. I. Zakharov ◽  
...  
Keyword(s):  
Reynolds Equation ◽  
Experimental Investigations ◽  
Diffusion Combustion ◽  
Operational Parameters ◽  
Gas Turbine Combustor ◽  
Nox Formation ◽  
Air Jets ◽  
Annular Combustor ◽  
Flow Heat ◽  
Swirled Flow

A mathematical model for the description of axisymmetric swirled flow with diffusion combustion is based on numerical solution of the Reynolds equation with a k–W model of turbulence. The results of numerical and experimental investigations of local and general characteristics of flow, heat and mass transfer, combustion, and NOx formation in an annular combustor with opposite swirled air jets are presented. Satisfactory agreement between calculations and experiments is obtained. The dependences of combustor characteristics versus geometric and operational parameters are generalized.

scholarly journals Mathematical Modelling of an Annular Gas Turbine Combustor

1993 ◽  
Author(s):  
K. Y. Sokolov ◽  
A. G. Tumanovskiy ◽  
M. N. Gutnik ◽  
A. V. Sudarev ◽  
Y. I. Zakharov ◽  
...  
Keyword(s):  
Reynolds Equation ◽  
Experimental Investigations ◽  
Diffusion Combustion ◽  
Operational Parameters ◽  
Gas Turbine Combustor ◽  
Nox Formation ◽  
Air Jets ◽  
Annular Combustor ◽  
Flow Heat ◽  
Swirled Flow

Mathematical model for description of axisymmetric swirled flow with diffusion combustion is based on numerical solution of Reynolds equation with k-W modell of turbulence. The results of numerical and experimental investigations of local and general characteristicse of flow, heat and mass transfer, combustion and NOx formation in annular combustor with opposite swirled air jets are presented. Satisfactory agreement between calculations and experiments is obtained. The dependences of combustor characteristics vs geometric and operational parameters are generalized.

scholarly journals Experimental Investigation of an Atmospheric Rectangular Rich Quench Lean Combustor Sector for Aeroengines

1997 ◽  
Author(s):  
Peter Griebel ◽  
Michael Fischer ◽  
Christoph Hassa ◽  
Eggert Magens ◽  
Henning Nannen ◽  
...  
Keyword(s):  
Research Work ◽  
Nox Formation ◽  
Lean Combustion ◽  
Air Jets ◽  
Primary Zone ◽  
Low Emission ◽  
Measuring Techniques ◽  
Annular Combustor ◽  
High Turbulence ◽  
Secondary Air

In this research work the potential of rich quench lean combustion for low emission aeroengines is investigated in a rectangular atmospheric sector, representing a segment of an annular combustor. For a constant design point (cruise) the mixing process and the NOx formation are studied in detail by concentration, temperature and velocity measurements using intrusive and non-intrusive measuring techniques. Measurements at the exit of the homogeneous primary zone show relatively high levels of non-thermal NO. The NOx formation in the quench zone is very low due to the quick mixing of the secondary air achieved by an adequate penetration of the secondary air jets and a high turbulence level. The NOx and CO emissions at the combustor exit are low and the pattern factor of the temperature distribution is sufficient.

Numerical Investigation of the Pressure Effect on the NOx Formation in a Lean-Premixed Gas Turbine Combustor

2021 ◽  
Vol 35 (8) ◽  
pp. 6776-6784
Author(s):  
Truc Huu Nguyen ◽  
Jungkyu Park ◽  
Changhun Sin ◽  
Seungchai Jung ◽  
Shaun Kim
Keyword(s):  
Numerical Investigation ◽  
Gas Turbine ◽  
Pressure Effect ◽  
Gas Turbine Combustor ◽  
Nox Formation ◽  
Lean Premixed

Numerical and Experimental Investigations on Preload Effects in Air Foil Journal Bearings

2017 ◽  
Author(s):  
Marcel Mahner ◽  
Pu Li ◽  
Andreas Lehn ◽  
Bernhard Schweizer
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Compressible Fluids ◽  
Experimental Investigations ◽  
Hysteresis Curves ◽  
Numerical Predictions ◽  
Bearing Stiffness ◽  
Gasdynamic Model ◽  
Good Agreement

A detailed elasto-gasdynamic model of a preloaded three-pad air foil journal bearing is presented. Bump and top foil deflections are herein calculated with a nonlinear beamshell theory according to Reissner. The 2D pressure distribution in each bearing pad is described by the Reynolds equation for compressible fluids. With this model, the influence of the assembly preload on the static bearing hysteresis as well as on the aerodynamic bearing performance is investigated. For the purpose of model validation, the predicted hysteresis curves are compared with measured curves. The numerically predicted and the measured hysteresis curves show a good agreement. The numerical predictions exhibit that the assembly preload increases the bearing stiffness (in particular for moderate shaft displacements) and the bearing damping.

Numerical and Experimental Investigations on the Residual Stresses at the Centre of Flat Glass Disks After Thermal Tempering

2008 ◽  
Vol 39-40 ◽  
pp. 553-558 ◽  
Author(s):  
Frédéric Soulié ◽  
Norbert Siedow ◽  
John Anton ◽  
Dominique Lochegnies
Keyword(s):  
Residual Stresses ◽  
Scattered Light ◽  
Flat Glass ◽  
Experimental Investigations ◽  
Stress Profile ◽  
Air Cooling ◽  
Conductive Heat ◽  
Air Jets ◽  
Complete Procedure ◽  
Disk Centre

Flat glass disks are thermally tempered by air-cooling with two air jets at the centre of their surfaces. Numerical modelling and photoelasticity measurements are proposed to analyze the distribution of the residual stresses through the glass thickness at the centre of the tempered disks. For the modelling, glass properties dependent of the temperature are used for the conductive heat transfer. Radiation is modelled by an improved approximation method. By taking both structural and stress relaxations into account, the transient and residual stresses are computed along the disk thickness. For experimentation, a complete procedure is proposed to access to the stress state in the centre of the disks using a scattered light polariscope. The average distribution of the residual stresses is deduced from stress profile measurements taking four radial orientations at the disk centre into consideration. Comparison between numerical and experimental values is finally discussed for the residual surface and half-thickness stresses at the disk centre.

Parameters affecting nitrifying biofilm reactors

1994 ◽  
Vol 29 (10-11) ◽  
pp. 1-11 ◽  
Author(s):  
M. Boller ◽  
W. Gujer ◽  
M. Tschui
Keyword(s):  
High Energy ◽  
Experimental Investigations ◽  
Operational Parameters ◽  
Oxygen Utilization ◽  
Trickling Filters ◽  
Biofilm Reactors ◽  
Biomass Activity ◽  
Rotating Biological Contactors ◽  
High Energy Consumption

The variables affecting nitrification in biofilms are identified on a theoretical basis. The influence of various design and operational parameters which affect the resulting substance fluxes into and out of the biofilm and the biomass activity regarding nitrification are illustrated with the help of experimental investigations with plastic media trickling filters, rotating biological contactors and different aerated biofilters. The results of experiments with these systems in tertiary nitrification applications reveal process limitations and technical measures to enhance nitrification performance in each system. In a case study, a comparison between the different biofilm processes and activated sludge alternatives showed that biofilm systems may lead to remarkably smaller reactor volumes, but high energy consumption due to unfavorable oxygen utilization.

Theoretical Study on Static Performance of Herringbone Grooved Aerodynamics Foil Bearing

2020 ◽  
Author(s):  
ZeDa Dong ◽  
Cheng Cheng ◽  
Fangcheng Xu
Keyword(s):  
Power Consumption ◽  
Reynolds Equation ◽  
Load Capacity ◽  
Structural Parameters ◽  
Operational Parameters ◽  
Film Pressure ◽  
Friction Power ◽  
Foil Bearings ◽  
Bearing Load ◽  
Herringbone Grooves

Abstract In this paper, the mathematical model of herringbone grooved aerodynamic foil bearings is established, and the finite difference method is used to obtain the discretized form of Reynolds equation. The static characteristics of bearings, such as film pressure, film temperature, are obtained by solving the Reynolds equation and energy equation. The bearing load capacity and friction power consumption are obtained by calculating the film thickness and film pressure distribution in the bearing gap. The influence of the bearing operational parameters, such as eccentricity and rotation speed, and the bearing structural parameters, such as groove width, groove depth ratio, groove number and helix angle, on the bearing load capacity and friction power consumption of bearings are analyzed. The methods of improving bearing load capacity and reducing friction power consumption are obtained. Simultaneously, by comparing the bearing load capacity and friction power consumption of herringbone grooved gas foil bearings and gas foil bearings (GFBs) without herringbone grooves, the influence of herringbone grooves on the bearing performance is obtained.

NOx formation from nitrogen in fuel and air during turbulent diffusion combustion

1977 ◽  
Vol 16 (1) ◽  
pp. 181-189 ◽  
Author(s):  
Toshimi Takagi ◽  
Mitsunobu Ogasawara ◽  
Masahito Daizo ◽  
Toshiharu Tatsumi
Keyword(s):  
Turbulent Diffusion ◽  
Diffusion Combustion ◽  
Nox Formation ◽  
Turbulent Diffusion Combustion

Effects of Burner Interaction on NOx Emission From Swirl Premix Burner in a Gas Turbine Combustor

2014 ◽  
Author(s):  
Cheon Hyeon Cho ◽  
Chae Hoon Sohn ◽  
Ju Hyeong Cho ◽  
Han Seok Kim
Keyword(s):  
Gas Turbine ◽  
Nox Emission ◽  
Gas Turbine Combustor ◽  
Step Size ◽  
Flow Temperature ◽  
Nox Formation ◽  
Air Stream ◽  
Flow Interactions ◽  
Model Chamber ◽  
Wall Interaction

Flame interaction between neighboring burners in a gas turbine combustor is investigated numerically for pursuit of its effect on NOx emission from the burners. In a model chamber or liner, EV burners with double cone are installed. Two burners with the same rotating direction of air stream are adopted and the distance between them is variable from 74.2 mm to 222.6 mm by the step size of 37.1 mm. Gaseous methane and air are adopted as fuel and oxidizer, respectively. From steady-state numerical analyses, flow, temperature, and NO concentration fields are calculated in all computational cases to find their correlation with NOx formation. NOx emission is evaluated at the exit of the model chamber with two burners as a function of burner distance and compared with that from a single burner. In all cases of two-burner calculations, NOx emission is higher than that of a single burner, which results from flow interactions between neighboring burners as well as between a burner and a liner wall. NOx emission is affected significantly by flow and flame interactions between them and strongly depends on burner distance. Burner interaction is divided into two regimes of a burner-burner interaction and a burner-wall interaction depending on the distance. In the former regime, NOx emission is reduced as flame interaction between burners is enhanced and in the latter regime, it is also reduced as interaction between the burner and the liner wall is enhanced.

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