scholarly journals Gas Turbine and Turbomachinery Education at Carleton University

Author(s):  
S. A. Sjolander ◽  
H. I. H. Saravanamuttoo

Although a relatively small industrial nation, Canada has a very well developed gas turbine industry with both an original design and manufacturing capability and a large industrial user base. Research and teaching at Carleton University has focused on the needs of the Canadian industry over many years. Particular strengths have been established in the areas of experimental aerodynamics for turbomachinery and the use of mathematical modelling for engine performance investigations. Strong links are maintained with both manufacturers and users, and the well-trained engineers produced by the program readily find employment in the industry.

Author(s):  
P. A. Phillips ◽  
Peter Spear

After briefly summarizing worldwide automotive gas turbine activity, the paper analyses the power plant requirements of a wide range of vehicle applications in order to formulate the design criteria for acceptable vehicle gas turbines. Ample data are available on the thermodynamic merits of various gas turbine cycles; however, the low cost of its piston engine competitor tends to eliminate all but the simplest cycles from vehicle gas turbine considerations. In order to improve the part load fuel economy, some complexity is inevitable, but this is limited to the addition of a glass ceramic regenerator in the 150 b.h.p. engine which is described in some detail. The alternative further complications necessary to achieve satisfactory vehicle response at various power/weight ratios are examined. Further improvement in engine performance will come by increasing the maximum cycle temperature. This can be achieved at lower cost by the extension of the use of ceramics. The paper is intended to stimulate the design application of the gas turbine engine.


Author(s):  
Peter D. Smout ◽  
Steven C. Cook

The determination of gas turbine engine performance relies heavily on intrusive rakes of pilot tubes and thermocouples for gas path pressure and temperature measurement. For over forty years, Kiel-shrouds mounted on the rake body leading edge have been used as the industry standard to de-sensitise the instrument to variations in flow incidence and velocity. This results in a complex rake design which is expensive to manufacture, susceptible to mechanical damage, and difficult to repair. This paper describes an exercise aimed at radically reducing rake manufacture and repair costs. A novel ’common cavity rake’ (CCR) design is presented where the pressure and/or temperature sensors are housed in a single slot let into the rake leading edge. Aerodynamic calibration data is included to show that the performance of the CCR design under uniform flow conditions and in an imposed total pressure gradient is equivalent to that of a conventional Kiel-shrouded rake.


2019 ◽  
Vol 91 (8) ◽  
pp. 1077-1085 ◽  
Author(s):  
Filip Wasilczuk ◽  
Pawel Flaszynski ◽  
Piotr Kaczynski ◽  
Ryszard Szwaba ◽  
Piotr Doerffer ◽  
...  

Purpose The purpose of the study is to measure the mass flow in the flow through the labyrinth seal of the gas turbine and compare it to the results of numerical simulation. Moreover the capability of two turbulence models to reflect the phenomenon will be assessed. The studied case will later be used as a reference case for the new, original design of flow control method to limit the leakage flow through the labyrinth seal. Design/methodology/approach Experimental measurements were conducted, measuring the mass flow and the pressure in the model of the labyrinth seal. It was compared to the results of numerical simulation performed in ANSYS/Fluent commercial code for the same geometry. Findings The precise machining of parts was identified as crucial for obtaining correct results in the experiment. The model characteristics were documented, allowing for its future use as the reference case for testing the new labyrinth seal geometry. Experimentally validated numerical model of the flow in the labyrinth seal was developed. Research limitations/implications The research studies the basic case, future research on the case with a new labyrinth seal geometry is planned. Research is conducted on simplified case without rotation and the impact of the turbine main channel. Practical implications Importance of machining accuracy up to 0.01 mm was found to be important for measuring leakage in small gaps and decision making on the optimal configuration selection. Originality/value The research is an important step in the development of original modification of the labyrinth seal, resulting in leakage reduction, by serving as a reference case.


Author(s):  
C. Rodgers

By the new millennia gas turbine technology standards the size of the first gas turbines of Von Ohain and Whittle would be considered small. Since those first pioneer achievements the sizes of gas turbines have diverged to unbelievable extremes. Large aircraft turbofans delivering the equivalent of 150 megawatts, and research micro engines designed for 20 watts. Microturbine generator sets rated from 2 to 200kW are penetrating the market to satisfy a rapid expansion use of electronic equipment. Tiny turbojets the size of a coca cola can are being flown in model aircraft applications. Shirt button sized gas turbines are now being researched intended to develop output powers below 0.5kW at rotational speeds in excess of 200 Krpm, where it is discussed that parasitic frictional drag and component heat transfer effects can significantly impact cycle performance. The demarcation zone between small and large gas turbines arbitrarily chosen in this treatise is rotational speeds of the order 100 Krpm, and above. This resurgence of impetus in the small gas turbine, beyond that witnessed some forty years ago for potential automobile applications, fostered this timely review of the small gas turbine, and a re-address of the question, what are the effects of size and clearances gaps on the performances of small gas turbines?. The possible resolution of this question lies in autopsy of the many small gas turbine component design constraints, aided by lessons learned in small engine performance development, which are the major topics of this paper.


2004 ◽  
Vol 128 (3) ◽  
pp. 579-584 ◽  
Author(s):  
Vassilios Pachidis ◽  
Pericles Pilidis ◽  
Fabien Talhouarn ◽  
Anestis Kalfas ◽  
Ioannis Templalexis

Background . This study focuses on a simulation strategy that will allow the performance characteristics of an isolated gas turbine engine component, resolved from a detailed, high-fidelity analysis, to be transferred to an engine system analysis carried out at a lower level of resolution. This work will enable component-level, complex physical processes to be captured and analyzed in the context of the whole engine performance, at an affordable computing resource and time. Approach. The technique described in this paper utilizes an object-oriented, zero-dimensional (0D) gas turbine modeling and performance simulation system and a high-fidelity, three-dimensional (3D) computational fluid dynamics (CFD) component model. The work investigates relative changes in the simulated engine performance after coupling the 3D CFD component to the 0D engine analysis system. For the purposes of this preliminary investigation, the high-fidelity component communicates with the lower fidelity cycle via an iterative, semi-manual process for the determination of the correct operating point. This technique has the potential to become fully automated, can be applied to all engine components, and does not involve the generation of a component characteristic map. Results. This paper demonstrates the potentials of the “fully integrated” approach to component zooming by using a 3D CFD intake model of a high bypass ratio turbofan as a case study. The CFD model is based on the geometry of the intake of the CFM56-5B2 engine. The high-fidelity model can fully define the characteristic of the intake at several operating condition and is subsequently used in the 0D cycle analysis to provide a more accurate, physics-based estimate of intake performance (i.e., pressure recovery) and hence, engine performance, replacing the default, empirical values. A detailed comparison between the baseline engine performance (empirical pressure recovery) and the engine performance obtained after using the coupled, high-fidelity component is presented in this paper. The analysis carried out by this study demonstrates relative changes in the simulated engine performance larger than 1%. Conclusions. This investigation proves the value of the simulation strategy followed in this paper and completely justifies (i) the extra computational effort required for a more automatic link between the high-fidelity component and the 0D cycle, and (ii) the extra time and effort that is usually required to create and run a 3D CFD engine component, especially in those cases where more accurate, high-fidelity engine performance simulation is required.


Author(s):  
K. Smith ◽  
A. Fahme

The design and development testing of a full scale, low emissions, ceramic combustor for a 5500 HP industrial gas turbine are described. The combustor was developed under a joint program conducted by the U.S. DOE and Solar Turbines. The ceramic combustor is designed to replace the production Centaur 50S SoLoNOx burner which uses lean-premixed combustion to limit NOx and CO to 25 and 50 ppm, respectively. Both the ceramic and production combustors are annular in shape and employ twelve premixing, natural gas fuel injectors. The ceramic combustor design effort involved the integration of two CFCC cylinders (76.2 cm [30 in.] and 35.56 cm [14 in.] diameters) into the combustor primary zone. The ceramic combustor was evaluated at Solar in full scale test rigs and a test engine. Performance of the combustor was excellent with high combustion efficiency and extremely low NOx and CO emissions. The hot walls of the ceramic combustor played a significant role in reducing CO emissions. This suggests that liner cooling air injected through the metal production liner contributes to CO emissions by reaction quenching at the liner walls. It appears that ceramics can serve to improve combustion efficiency near the combustor lean limit which, in turn, would allow further reductions in NOx emissions. Approximately 50 hours of operation have been accumulated using the ceramic combustor. No significant deterioration in the CFCC liners has been observed. A 4000 hour field test of the combustion system is planned to begin in 1997 as a durability assessment.


Author(s):  
G. K. Conkol ◽  
T. Singh

As vehicles evolve through the concept phase, a wide variety of engines are usually considered. For long-life vehicles such as heavy armored tracked vehicles, gas turbines have been favored because of their weight and volume characteristics at high hp levels (1500 to 2000 hp). Many existing gas turbine engines, however, are undesirable for vehicular use because their original design philosophy was aircraft oriented. In a ground vehicle, mass flow and expense are only two areas in which these engines differ greatly. Because the designer generally is not given the freedom to design an engine from scratch, he must evaluate modifications of the basic Brayton cycle. In this study, various cycles are evaluated by using a design point program in order to optimize design parameters and to recommend a cycle for heavy vehicular use.


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