Gas Turbine Performance Simulation Using an Optimized Axial Flow Compressor

Author(s):  
Cleverson Bringhenti ◽  
Jesui´no Takachi Tomita ◽  
Francisco de Sousa Ju´nior ◽  
Joa˜o R. Barbosa

Gas turbines need to operate efficiently due to the high specific fuel consumption. In order to reach the best possible efficiency the main gas turbine components, such as compressor and turbine, need to be optimized. This work reports the use of two specially developed computer programs: AFCC [1, 2] and GTAnalysis [3, 4] for such purpose. An axial flow compressor has been designed, using the AFCC computer program based on the stage-stacking technique. Major compressor design parameters are optimized at design point, searching for best efficiency and surge margin. Operation points are calculated and its characteristics maps are generated. The calculated compressor maps are incorporated to the GTAnalysis computer program for the engine performance calculation. Restrictions, like engine complexity, manufacture difficulties and control problems, are not taken into account.

Author(s):  
Cyrus B. Meher-Homji ◽  
Mustapha Chaker ◽  
Andrew F. Bromley

Increased fuel costs have created a strong incentive for gas turbine operators to understand, minimize and control performance deterioration. The most prevalent deterioration problem faced by gas turbine operators is compressor fouling. Fouling causes a drop in airflow, pressure ratio and compressor efficiency, resulting in a “re-matching” of the gas turbine and compressor and a drop in power output and thermal efficiency. This paper addresses the causes and effects of fouling and provides a comprehensive treatment of the impact of salient gas turbine design parameters on the susceptibility and sensitivity to compressor fouling. Simulation analysis of ninety two (92) gas turbines of ranging from a few kW to large engines rated at greater than 300 MW has been conducted. It is hoped that this paper will provide practical information to gas turbine operators.


Author(s):  
Y. Kashiwabara ◽  
Y. Katoh ◽  
H. Ishii ◽  
T. Hattori ◽  
Y. Matsuura ◽  
...  

In this paper, the development leading to a 17-stage axial flow compressor (pressure ratio 14.7) for the 25 MW class heavy duty gas turbine H-25 is described. In the course of developing the H-25’s compressor, extensive measurements were carried out on models. Experimental results are compared with predicted values. Aerodynamic experiments covered the measurements of unsteady flows such as rotating stall and surge as well as the steady-state performance of the compressor. Based on the results of these tests, the aerodynamic and mechanical design parameters of the full scale H-25 compressor were finalized on the basis of two model compressors. Detailed measurements of the first unit of the H-25 gas turbine were carried out. Test results on the compressor are presented and show the achievement of the expected design targets.


Author(s):  
Justin (Jongsik) Oh

In many aerodynamic design parameters for the axial-flow compressor, three variables of tailored blading, blade lean and sweep were considered in the re-design efforts of a transonic single stage which had been designed in 1960’s NASA public domains. As Part 1, the re-design was limited to the stator vane only. For the original MCA (Multiple Circular Arc) blading, which had been applied at all radii, the CDA (Controlled Diffusion Airfoil) blading was introduced at midspan as the first variant, and the endwalls of hub and casing (or tip) were replaced with the DCA (Double Circular Arc) blading for the second variant. Aerodynamic performance was predicted through a series of CFD analysis at design speed, and the best aerodynamic improvement, in terms of pressure ratio/efficiency and operability, was found in the first variant of tailored blading. It was selected as a baseline for the next design efforts with blade lean, sweep and both combined. Among 12 variants, a case of positively and mildly leaned blades was found the most attractive one, relative to the original design, providing benefits of an 1.0% increase of pressure ratio at design flow, an 1.7% increase of efficiency at design flow, a 10.5% increase of the surge margin and a 32.3% increase of the choke margin.


Author(s):  
Jesuino Takachi Tomita ◽  
Luciano Porto Bontempo ◽  
João Roberto Barbosa

The first steps of the turbomachinery design usually rely on numerical tools based on inviscid formulation with corrections using loss models to account for viscous effects, secondary flows, tip clearances, and shock waves. The viscous effects are accounted for using semi-empirical correlations especially assembled for the chosen airfoils and range of operating conditions. Fast convergence and good accuracy are required from such design procedures. There are successful models that produce very accurate performance prediction. Among the methodologies commonly used, the streamline curvature (SLC) is used since those characteristics and the most important properties can be calculated reasonably well at any radial positions, assisting other more complex analysis programs. The SLC technique is, therefore, well suited for the design of axial flow compressors for reasons such as quick access to vital flow properties at the blade edges from which actions may be taken to improve its performance at the design stage. This work reports the association of a SLC computer program and commercial software for comparison purposes, as well as for grid generation required by a full 3D, turbulent Navier–Stokes computer program used for flow calculation in the blade passages. Application to a high performance three-stage axial flow compressor with inlet guide vane demonstrates the methodology adopted. The SLC program is also capable of calculating the compressor performance with humid air and water injection at any axial position along the compressor. The influence of water injection at different axial positions, water particle diameter, and temperature of water particles were studied for different humid air conditions. The positions of the evaporating water particles were calculated using their thermophysical and dynamic properties along the compressor.


Author(s):  
I. N. Egorov ◽  
G. V. Kreitinin

A numerical method has been preposed to determine optimum laws to control gas turbine engine (CTE) variable components, including an independent control of blade rows in a multistage axial flow compressor under strong non-stationary flow disturbances at the inlet, optimum laws to control a turbofan under non-stationary thermal effects at the inlet have been obtained using mathematical models with various degree of filling in detail the flow in an engine flow path. There is shown a possibility to considerably increase a range of the CTE stable operation through the use of dynamic control of stator blades in a multistage axial flow compressor, also possibilities of practical use of optimum laws to control engine variable components in the system of preventing an unstable operation are being discussed.


1947 ◽  
Vol 157 (1) ◽  
pp. 471-482 ◽  
Author(s):  
D. M. Smith

The paper reviews the technical development of the F2 jet propulsion engine, an axial flow gas turbine designed and manufactured by the Metropolitan-Vickers Electrical Company, Limited, under contract from the Ministry of Aircraft Production. An account is given of the preliminary work in 1938–9, in collaboration with the Royal Aircraft Establishment, on gas turbines for aircraft propulsion. The development of a simple jet engine of the axial flow type was started in July 1940. The first engine ran on bench test in December 1941. The first flights took place in June 1943 on a flying testbed, and in November 1943 on a jet-propelled aircraft. The evolution of engines of this type, leading up to the current F2/4 jet propulsion engine, is described. Each main component of the engine—the axial flow compressor, the annular combustion chamber and the high temperature turbine—necessitated extensive development work in fields previously unexplored; the methods used in the development of these and other components are explained. The F2 engine was the first British jet propulsion engine of axial flow type, and it is also unique amongst British engines in the straight-through design and annular combustion chamber that gives an exceptionally low frontal area.


Author(s):  
I. N. Egorov ◽  
G. V. Kretinin

Procedure for the stochastic optimization of design parameters of gas turbine engine components for a prescribed level of production technology is discussed. Such combined criteria of the stochastic optimization as effectiveness-probability of realizing a design of an intricate technical object are proposed. With reference to the task of optimum designing the rows of a multistage axial flow compressor, there are presented the results, obtained for various probability criteria, in parallel with conducting their comparative analysis, and there are also investigated optimum stable (robust) characteristics of designs obtained for various levels of technology. There are also demonstrated a possibility of a significant increase in probability to realize in actual practice the design, obtained in stochastic setting, as compared to the design, obtained in deterministic setting.


1996 ◽  
Author(s):  
Katsushi Nagai ◽  
Kazuaki Ikesawa ◽  
Takao Sugimoto ◽  
Toshinao Tanaka ◽  
Hiroshi Umino ◽  
...  

A highly loaded two stage transonic axial flow compressor, which forms a front stages of a multi stage compressor for industrial gas turbines, has been designed and tested. Overall pressure ratio is 2.25 and the first stage rotor tip Mach number is 1.15. Two airfoil types, Double Circular Arc airfoil and Multi Circular Arc airfoil, were designed for a transonic rotor blade under the same condition. MCA blade design method was devised and introduced. The blade design relied heavily on CFD techniques using a Euler code and a Navier Stokes code to cope with a precise treatment. The rig test was conducted by our compressor test facility to verify a validity of the transonic compressor design method and to compare the performance of the DCA and the MCA airfoils. This report describes the aerodynamic design and the test results as well as the test facility and instrumentation.


Author(s):  
Kazutoyo Yamada ◽  
Masato Furukawa ◽  
Satoshi Nakakido ◽  
Akinori Matsuoka ◽  
Kentaro Nakayama

The paper presents the results of large-scale numerical simulations which were conducted for better understanding of unsteady flow phenomena in a multi-stage axial flow compressor at off-design condition. The compressor is a test rig compressor which was used for development of the industrial gas turbine, Kawasaki L30A. The compressor consists of 14 stages, the front two stages and the front half stages of which were investigated in the present study. The final goal of this study is to elucidate the flow mechanism of the rotating stall inception in the multi-stage axial compressor for actual gas turbines, and according to the test data it is considered that the 2nd stage and the 5th or 6th stage are suspected of leading to the stall. In order to capture precise flow physics in the compressor, a computational mesh for the simulation was generated to have at least several million cells per passage, which amounted to 650 million cells for the front 2-stage simulation and two billion cells for the front 7-stage simulation (about three hundred million cells for each stage). Since these were still not enough for the large-eddy simulation (LES), the detached-eddy simulation (DES) was employed, which can calculate flow fields except near-wall region by LES. The required computational resources were quite large for such simulations, so the computations were conducted on the K computer (RIKEN AICS in Japan). The simulations were well validated, showing good agreement with the measurement results obtained in the test. In the validation, the effect of the boundary condition for the casing wall was also investigated by comparing the results between the adiabatic boundary condition and the isothermal boundary condition. As for the unsteady effect, the wake/blade interaction was investigated in detail. In addition, unsteady flow phenomena in the present compressor at off-design condition were analyzed by using data mining techniques such as vortex identification and limiting streamline drawing with the LIC (line integral convolution) method. The simulation showed that they could be caused by the corner separation on the hub side.


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