Download or read book A Network Approach for the Prediction of Flow and Flow Splits Within a Gas Turbine Combustor written by Johannes Jacobus Pretorius and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The modern gas turbine engine industry needs a simpler and faster method to facilitate the design of gas turbine combustors due to the enormous costs of experimental test rigging and detailed computational fluid dynamics (CFD) simulations. Therefore, in the initial design phase, a couple of preliminary designs are conducted to establish initial values for combustor performance and geometric characteristics. In these preliminary designs, various one-dimensional models using analytical and empirical formulations may be used. One of the disadvantages of existing models is that they are typically geometric dependant, i.e. they apply only to the geometry they are derived for. Therefore the need for a more versatile design tool exists. In this work, which constitutes the first step in the development of such a versatile design tool, a single equation-set network simulation model to describe both steady state compressible and incompressible isothermal flow is developed. The continuity and momentum equations are solved through a hybrid type network model analogy which makes use of the SIMPLE pressure correction methodology. The code has the capability to efficiently compute flow through elements where the loss factor K is highly flow dependant and accurately describes variable area duct flow in the case of incompressible flow. The latter includes ducts with discontinuously varying flow sectional areas. Proper treatment of flow related non-linearities, such as flow friction, is facilitated in a natural manner in the proposed methodology. The proposed network method is implemented into a Windows based simulation package with a user interface. The ability of the proposed method to accurately model both compressible and incompressible flow is demonstrated through the analyses of a number of benchmark problems. It will be shown that the proposed methodology yields similar or improved results as compared to other's work. The proposed method is applied to a research combustor to solve for isothermal flows and flow splits. The predicted flows were in relatively close agreement with measured data as well as detailed CFD analysis.
Download or read book Combining a One dimensional Empirical and Network Solver with Computational Fluid Dynamics to Investigate Possible Modifications to a Commercial Gas Turbine Combustor written by Johannes Jacobus Gouws and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas turbine combustion chambers were traditionally designed through trial and error which was unfortunately a time-consuming and expensive process. The development of computers, however, contributed a great deal to the development of combustion chambers, enabling one to model such systems more accurately in less time. Traditionally, preliminary combustor designs were conducted with the use of one-dimensional codes to assist in the prediction of flow distributions and pressure losses across the combustion chamber mainly due to their rapid execution times and ease of use. The results are generally used as boundary conditions in three- dimensional models to predict the internal flow field of the combustor. More recent studies solve the entire flow field from prediffuser to combustor exit. This approach is, however, a computationally expensive procedure and can only be used if adequate computer resources are available. The purpose of this study is two-fold: (1) to develop a one-dimensional incompressible code, incorporating an empirical-based combustion model, to assist a one-dimensional network solver in predicting flow- and temperature distributions, as well as pressure losses. This is done due to the lack of a combustion model in the network solver that was used. An incompressible solution of flow splits, pressure losses, and temperature distributions is also obtained and compared with the compressible solution obtained by the network solver: (2) to utilise the data, obtained from the network solver, as boundary conditions to a three-dimensional numerical model to investigate possible modifications to the dome wall of a standard T56 combustion chamber. A numerical base case model is validated against experimental exit temperature data, and based upon that comparison, the remaining numerical models are compared with the numerical base case. The effect of the modification on the dome wall temperature is therefore apparent when the modified numerical model is compared with the numerical base case. A second empirical code was developed to design the geometry of axial straight vane swirlers with different swirl angles. To maintain overall engine efficiency, the pressure loss that was determined from the network analysis, of the base case model, is used during the design of the different swirlers. The pressure loss across the modified combustion chamber will therefore remain similar to that of the original design. Hence, to maintain a constant pressure loss across the modified combustion chambers, the network solver is used to determine how many existing hole features should be closed for the pressure loss to remain similar. The hole features are closed, virtually, in such a manner as not to influence the equivalence ratio in each zone significantly, therefore maintaining combustion performance similar to that of the original design. Although the equivalence ratios in each combustion zone will be more or less unaffected, the addition of a swirler will influence the emission levels obtained from the system due to enhanced air-fuel mixing. A purely numerical parametric analysis was conducted to investigate the influence of different swirler geometries on the dome wall temperature while maintaining an acceptable exit temperature distribution. The data is compared against the data obtained from an experimentally validated base case model. The investigation concerns the replacement of the existing splash-cooling devices on the dome wall with that of a single swirler. A number of swirler parameters such as blade angle, mass flow rate, and number of blades were varied during the study, investigating its influence on the dome wall temperature distribution. Results showed that the swirlers with approximately the same mass flow as the existing splash-cooling devices had almost no impact on the dome wall temperatures but maintained the exit temperature profile. An investigation of swirlers with an increased mass flow rate was also done and results showed that these swirlers had a better impact on the dome wall temperatures. However, due to the increased mass flow rate, stable combustion is not guaranteed since the air/fuel ratio in the primary combustion zone was altered. The conclusion that was drawn from the study, was that by simply adding an axial air swirler might reduce high-temperature gradients on the dome but will not guarantee stable combustion during off-design operating conditions. Therefore, a complete new hole layout design might be necessary to ensure good combustion performance across a wide operating range.
Download or read book ASME Technical Papers written by and published by . This book was released on 2000 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Paper written by and published by . This book was released on 2000 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Prediction of Gas Turbine Combustor Flow by a Finite Element Code written by D. Lentini and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experiments and Numerical Simulations of Diluted Spray Turbulent Combustion written by Bart Merci and published by Springer Science & Business Media. This book was released on 2011-06-20 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reflects the outcome of the 1st International Workshop on Turbulent Spray Combustion held in 2009 in Corsica (France). The focus is on reporting the progress of experimental and numerical techniques in two-phase flows, with emphasis on spray combustion. The motivation for studies in this area is that knowledge of the dominant phenomena and their interactions in such flow systems is essential for the development of predictive models and their use in combustor and gas turbine design. This necessitates the development of accurate experimental methods and numerical modelling techniques. The workshop aimed at providing an opportunity for experts and young researchers to present the state-of-the-art, discuss new developments or techniques and exchange ideas in the areas of experimentations, modelling and simulation of reactive multiphase flows. The first two papers reflect the contents of the invited lectures, given by experts in the field of turbulent spray combustion. The first concerns computational issues, while the second deals with experiments. These lectures initiated very interesting and interactive discussions among the researchers, further pursued in contributed poster presentations. Contributions 3 and 4 focus on some aspects of the impact of the interaction between fuel evaporation and combustion on spray combustion in the context of gas turbines, while the final article deals with the interaction between evaporation and turbulence.
Download or read book Numerical Prediction of Flow Thermal and Stress Fields in Gas Turbine Combustor Components written by John K. Luff and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1987 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Numerical Study of Flow in Gas turbine Combustor written by W. Shyy and published by . This book was released on 1987 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of a Combustor Flow Analysis Part I Theoretical Studies written by Robert F. Anasoulis and published by . This book was released on 1974 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: A computational procedure for calculating the coupled flow and chemistry within both can-annular and annular gas turbine combustors is presented. The procedure solves the time-averaged Navier-Stokes equations with coupled chemistry including the effects of turbulence and droplet vaporization and burning, using a novel field relaxation method developed at the United Aircraft Research Laboratories. Although a relatively simple turbulence model is employed in the procedure, modification to this model is easily implemented within the framework of the computational method. Computations of the flow and chemistry within both can-annular and annular gas turbine combustors, conducted using the procedure, are presented and compared with experimental data. The results of the comparisons with data are obscured by three-dimensional effects present in real gas turbine combustors. However, the indications are that, for combustors where has considerable potential. (Author).
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 974 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preliminary Determination and Interpretation of Flow Patterns in a Gas Turbine Combustor written by R.E. Pavia and published by . This book was released on 1956 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA SP written by and published by . This book was released on 1992 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Three dimensional Grid Generation Method for Gas turbine Combustor Flow Computations written by Wei Shyy and published by . This book was released on 1987 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeronautical Engineering written by and published by . This book was released on 1991 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 36th Aerospace Sciences Meeting Exhibit written by and published by . This book was released on 1998 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt:
