scholarly journals Gas Turbine Combustor Development Tools for Production Designs

1985 ◽  
Author(s):  
Stephen N. Finger ◽  
Thomas L. Dubell
Keyword(s):  
Gas Turbine ◽  
Three Dimensional ◽  
Separated Flow ◽  
Preliminary Design ◽  
Trial And Error ◽  
Gas Turbine Combustor ◽  
Two Phase ◽  
Turbine Engine ◽  
Fundamental Knowledge ◽  
Black Art

Gas turbine engine combustor design and development has long held a somewhat undeserved reputation as a “Black Art”. This reputation was earned because those unfamiliar with the technology perceived the large amount of development testing required indicated a lack of fundamental knowledge of combustion. Fundamental knowledge exists and provides the foundation for design and to guide decisions on development. However, considerable trial and error work is required to satisfy many and sometimes conflicting performance goals because complete quantification of separated flow aerodynamics, three dimensional flowfields, anisotropic two phase flow, chemical reaction and heat addition is a challenge not yet met. Therefore, there is considerable reliance on use of rigs during the preliminary design phase and on the use of rigs and engines during development. Well founded use of experimental tools is necessary and must be adequately planned for in any program for a combustor intended for production. This paper describes these tools and how they should be used in such a program.

scholarly journals Assessment of Combustor Working Environments

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Leiyong Jiang ◽  
Andrew Corber
Keyword(s):  
Gas Turbine ◽  
Operating Conditions ◽  
Reacting Flow ◽  
Gas Turbine Combustor ◽  
Two Phase ◽  
Turbine Engine ◽  
Working Environments ◽  
Flow Features ◽  
Critical Components ◽  
The Cost

In order to assess the remaining life of gas turbine critical components, it is vital to accurately define the aerothermodynamic working environments and service histories. As a part of a major multidisciplinary collaboration program, a benchmark modeling on a practical gas turbine combustor is successfully carried out, and the two-phase, steady, turbulent, compressible, reacting flow fields at both cruise and takeoff are obtained. The results show the complicated flow features inside the combustor. The airflow over each flow element of the combustor can or liner is not evenly distributed, and considerable variations, ±25%, around the average values, are observed. It is more important to note that the temperatures at the combustor can and cooling wiggle strips vary significantly, which can significantly affect fatigue life of engine critical components. The present study suggests that to develop an adequate aerothermodynamics tool, it is necessary to carry out a further systematic study, including validation of numerical results, simulations at typical engine operating conditions, and development of simple correlations between engine operating conditions and component working environments. As an ultimate goal, the cost and time of gas turbine engine fleet management must be significantly reduced.

On the Prediction of Swirling Flowfields Found in Axisymmetric Combustor Geometries

1982 ◽  
Vol 104 (3) ◽  
pp. 378-384 ◽  
Author(s):  
D. L. Rhode ◽  
D. G. Lilley ◽  
D. K. McLaughlin
Keyword(s):  
Gas Turbine ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Boundary Representation ◽  
Reacting Flow ◽  
Gas Turbine Combustor ◽  
Turbine Engine ◽  
Research Activities ◽  
Gradual Expansion ◽  
Neutrally Buoyant

Combustor modeling has reached the stage where the most useful research activities are likely to be on specific sub-problems of the general three-dimensional turbulent reacting flow problem. The present study is concerned with a timely fluid dynamic research task of interest to the combustor modeling community. Numerical computations have been undertaken for a basic two-dimensional axisymmetric flowfield which is similar to that found in a conventional gas turbine combustor. A swirling nonreacting flow enters a larger chamber via a sudden or gradual expansion. The calculation method includes a stairstep boundary representation of the expansion flow, a conventional k-ε turbulence model and realistic accommodation of swirl effects. The results include recirculation zone characterization and predicted mean streamline patterns. In addition, an experimental evaluation using flow visualization of neutrally-buoyant helium-filled soap bubbles is yielding very promising results. Successful outcomes of the work can be incorporated into the more combustion- and hardware-oriented activities of gas turbine engine manufacturers, including incorporating the modeling aspects into already existing comprehensive numerical solution procedures.

Performance Improvement of an Aero Gas Turbine Combustor

2009 ◽  
Author(s):  
M. Srinivasa Rao ◽  
G. Sivaramakrishna
Keyword(s):  
Gas Turbine ◽  
Performance Improvement ◽  
Three Dimensional ◽  
Gas Turbine Engine ◽  
Vital Role ◽  
Design Development ◽  
Gas Turbine Combustor ◽  
Specific Design ◽  
Turbine Engine ◽  
Dynamics Analyses

The HETD (Hot End Technologies Directorate) of GTRE (Gas Turbine Research Establishment) has the mandate of design, development and delivery of airworthy combustor and afterburner modules for a military aero gas turbine engine. In order to meet the mandate, the directorate takes the overall responsibility of design to manufacture of the combustion systems. Three-dimensional CFD (Computational Fluid Dynamics) analyses played a vital role in arriving at the final configuration meeting the specific design targets. This paper focuses on the utilization of the CFD code ‘Fluent’ in the successful realization of the main combustor of an aero gas turbine engine.

Large-Eddy Simulation of Reacting Turbulent Flows in Complex Geometries

2005 ◽  
Vol 73 (3) ◽  
pp. 374-381 ◽  
Author(s):  
K. Mahesh ◽  
G. Constantinescu ◽  
S. Apte ◽  
G. Iaccarino ◽  
F. Ham ◽  
...  
Keyword(s):  
Large Eddy Simulation ◽  
Gas Turbine ◽  
Turbulent Flows ◽  
Reacting Flows ◽  
Gas Turbine Combustor ◽  
Turbine Engine ◽  
Progress Variable ◽  
Eddy Simulation ◽  
Variable Approach ◽  
Large Eddy

Large-eddy simulation (LES) has traditionally been restricted to fairly simple geometries. This paper discusses LES of reacting flows in geometries as complex as commercial gas turbine engine combustors. The incompressible algorithm developed by Mahesh et al. (J. Comput. Phys., 2004, 197, 215–240) is extended to the zero Mach number equations with heat release. Chemical reactions are modeled using the flamelet/progress variable approach of Pierce and Moin (J. Fluid Mech., 2004, 504, 73–97). The simulations are validated against experiment for methane-air combustion in a coaxial geometry, and jet-A surrogate/air combustion in a gas-turbine combustor geometry.

Study of Oil Film Heat Transfer in Gas Turbine Engine Bearing Chamber

2021 ◽  
Author(s):  
Illia Petukhov ◽  
Taras Mykhailenko ◽  
Oleksii Lysytsia ◽  
Artem Kovalov
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Gas Turbine ◽  
Gas Turbine Engine ◽  
Flow Core ◽  
Two Phase ◽  
Turbine Engine ◽  
Oil Film ◽  
Phase Medium ◽  
Engine Bearing

Abstract A clear understanding of the heat transfer processes in a gas turbine engine bearing chamber at the design stage makes it possible to properly design the lubrication and sealing systems and ensure the future bearing safe operation. The heat transfer coefficient (HTC) calculated based on the classical Newton-Richman equation is widely used to represent the heat transfer data and useful for the thermal resistance analysis. However, this approach is only formally applicable in the case of a two-phase medium. While there is a need to model a two-phase medium, setting the flow core temperature correctly in the Newton-Richman equation is an issue that is analyzed in this study. The heat from the flow core is transferred to the boundary of the oil film on the bearing chamber walls by an adjacent air and precipitating droplets. The analysis showed that droplet deposition plays a decisive role in this process and significantly intensifies the heat transfer. The main contribution to the thermal resistance of internal heat transfer is provided by the oil film. In this regard, the study considers the issues of the bearing chamber workflow modeling allowing to determine the hydrodynamic parameters of the oil film taking into account air and oil flow rates and shaft revolutions. The study also considers a possibility to apply the thermohydraulic analogy methods for the oil film thermal resistance determination. The study presents practical recommendations for process modeling in the bearing chamber.

Three-Dimensional Computation of Gas Turbine Combustors and the Validation Studies of Turbulence and Combustion Models

1997 ◽  
Author(s):  
D. Biswas ◽  
K. Kawano ◽  
H. Iwasaki ◽  
M. Ishizuka ◽  
S. Yamanaka
Keyword(s):  
Gas Turbine ◽  
Validation Studies ◽  
Three Dimensional ◽  
Chemical Species ◽  
Reaction Rates ◽  
Reacting Flows ◽  
Gas Turbine Combustor ◽  
Combustion Models ◽  
Rate Of Dissipation

The main aim or the present work is to explore computational fluid dynamics and related turbulence and combustion models for application to the design, understanding and development of gas turbine combustor. Validation studies were conducted using the Semi-Implicit Method for Pressure Linked Equations (SIMPLE) scheme to solve the relevant steady, elliptical partial differential equations of the conservation of mass, momentum, energy and chemical species in three-dimensional cylindrical co-ordinate system to simulate the gas turbine combustion chamber configurations. A modified version of k-ε turbulence model was used for characterization of local turbulence in gas turbine combustor. Since, in the present study both diffusion and pre-mixed combustion were considered, in addition to familiar bi-molecular Arhenius relation, influence of turbulence on reaction rates was accounted for based on the eddy break up concept of Spalding and was assumed that the local reaction rate was proportional to the rate of dissipation of turbulent eddies. Firstly, the validity of the present approach with the turbulence and reaction models considered is checked by comparing the computed results with the standard experimental data on recirculation zone, mean axial velocity and temperature profiles, etc. for confined, reacting and non-reacting flows with reasonably well defined boundary conditions. Finally, the results of computation for practical gas turbine combustor using combined diffusion and pre-mixed combustion for different combustion conditions are discussed.

Gas Turbine Engine Test Cell Modeling

1990 ◽  
Author(s):  
D. Salinas ◽  
E. E. Cooper
Keyword(s):  
Kinetic Energy ◽  
Gas Turbine ◽  
Three Dimensional ◽  
Gas Turbine Engine ◽  
Test Cell ◽  
Dimensional System ◽  
Engine Test ◽  
Turbine Engine ◽  
Coordinate Model ◽  
Cartesian Coordinate

A numerical simulation of the aerothermal characteristics of a gas turbine engine test cell is presented. The three-dimensional system is modeled using the PHOENICS computational fluid dynamics code. Results predict the velocity field, temperatures, pressures, kinetic energy of turbulence, and dissipation rates of turbulent kinetic energy. Numerical results from two versions, a cartesian coordinate model and a body fitted coordinate model, are compared to experimental data. The comparison shows good quantitative and very good qualitative agreement, suggesting that numerical modeling would be useful in the preliminary design of gas turbine test facilities.

scholarly journals Study of Two-Phase Flow Downstream of a Gas Turbine Combustor Dome Swirl Cup

1993 ◽  
Author(s):  
Anil K. Tolpadi ◽  
David L. Burrus ◽  
Robert J. Lawson
Keyword(s):  
Phase Velocity ◽  
Gas Turbine ◽  
Gas Phase ◽  
Frame Of Reference ◽  
Droplet Velocity ◽  
Computational Domain ◽  
Gas Turbine Combustor ◽  
Two Phase ◽  
Number Count ◽  
Good Agreement

The two-phase axisymmetric flowfield downstream of the swirl cup of an advanced gas turbine combustor is studied numerically. The swirl cup analyzed is that of a single annular GE/SNECMA CFM56 turbofan engine that is comprised of a pair of coaxial counter-swirling air streams together with a fuel atomizer. The atomized fuel mixes with the swirling air stream resulting in the establishment of a complex two-phase flowfield within the swirl chamber. The analysis procedure involves the solution of the gas phase equations in a Eulerian frame of reference. The flow is assumed to be nonreacting and isothermal. The liquid phase is simulated by using a droplet spray model and by treating the motion of the fuel droplets in a Lagrangian frame of reference. Extensive Phase Doppler Particle Analyzer (PDPA) data for the CFM56 engine swirl cup has been obtained at atmospheric pressure by using water as the fuel (Wang et al., 1992a). This includes measurements of the gas phase velocity in the absence and presence of the spray together with the droplet size, droplet number count and droplet velocity distribution information at various axial stations downstream of the injector. Numerical calculations were performed under the exact inlet and boundary conditions as the experimental measurements. The computed gas phase velocity field showed good agreement with the test data. The agreement was found to be best at the stations close to the primary venturi of the swirler and to be reasonable at later stations. To compare the droplet data, a numerical PDPA scheme was formulated whereby several sampling volumes were selected within the computational domain. The trajectories of various droplets passing through these volumes were monitored and appropriately integrated. The calculated droplet count and mean droplet velocity distributions were compared with the measurements and showed very good agreement in the case of larger size droplets and fair agreement for smaller size droplets.

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