Stator assembly for an axial compressor societe national. An axial compressor is typically made up of many alternating rows of rotating and stationary blades called rotors and stators, respectively, as shown in figures 12. Influence of changes of axial compressor variable stator vanes. The single stage compressor used in these tests is shown in figures 1 and 2. Modelling the characteristics of axial compressor with variable stator vanes the coloured lines on the characteristics represent the compressor s operation at three angular settings of inlet guide vane blades, dkw, and the compressor rotational speed, n1, which is constant. The rotor blades black are fixed to the rotor drum. Summary the paper deals with the problem concerning the influence of changes in the variable stator vanes axial compressor settings of a gas turbine engine on work parameters of compressor and engine. Ep0545656a1 variable stator vane assembly for an axial flow. A supporting ring for stator vanes in an axial compressor. What is the key importance of variable stator vanes in an axial compressor of a gas turbine.
It is a rotating, airfoilbased compressor in which the gas or working fluid principally flows parallel to the axis of rotation, or axially. I general view of the an250 testing facilities at the ge nuovo pignone florence plant. Axial compressor considerations flow control network. Incorrect operation of the change setting system of. The study of the performance of a gas turbine power plant involves complex components. Axial compressor stall and surge prediction by measurements. The adjustable stators allow the stator to be positioned to the correct flow angle leaving the blades as the air mass flow varies with load and inlet temperature. A detailed investigation of the stresses in the early stator blade rows of an axialflow compressor. Stationary vanes of axial flow compressors are typically. The method involves simultaneous resetting of several. The adjustment is carried out by removing the stator body while the machine is at standstill. Oneill communicated by the directorgeneral of scientific research air ministry of supply reports and memoranda no. A housing having 27 a central bore 28 and a bushing assembly 30 is located in the casing bore 25 and is bolted to the boss. Pdf numerical optimization of a stator vane setting in.
Between each row of rotating blades in a turbine engine compressor, there is a row of stationary blades which act to diffuse the air. The characteristics of this compressor are presented in reference 7. This situation is unacceptable because of mechanica l overloads which could demage the engine. The casings of axial flow compressors not only support the stator vanes and provide the outer wall of the axial path the air follows, but they also provide the means for extracting compressor air for various purposes. Nasa stage 37 and the threestage nasa 74a axial compressors were analyzed and. Free ppt and pdf download for compressor study mafia. The first stationary row which comes in front of the rotor is typically called the inlet guide vanes or igv each successive rotor stator pair is called a compressor stage. On initiation of stall in axial flow compressors mdpi. Air flows axially into the compressor which has rotating blades. The development of some key structural design technologies to realize the original intent of an aerodynamic design is also described, including higher accuracy variable stator vane actuation, tip. Conventional highpressure turbine blades and vanes are made from nickel based alloys and often use.
Stator assembly for an axial compressor societe national d. Pdf influence of changes of axial compressor variable. The first part of the centrifugal impeller looks very similar to an axial compressor. Design and analysis of stator, rotor and blades of axial flow compressor issn. An axial flow compressor compresses its working fluid by first accelerating the fluid and then diffusing it to obtain a pressure increase chapter 7. Compressor stage geomtry ratio r ir o, both of which are assumed constant.
In the axial compressor, the air flows parallel to the axis of rotation. Modelling the characteristics of axial compressor with variable stator vanes the coloured lines on the characteristics represent the compressors operation at three angular settings of inlet guide vane blades, dkw, and the compressor rotational speed, n1, which is constant. Effect of stator variability on axial compressor performance. Nonlinear aeromechanical behaviour of axial core compressor.
Boyce, in gas turbine engineering handbook fourth edition, 2012. Centrifugal compressors are similar to axial compressors in that they are rotating airfoilbased compressors. For the purpose to improve the efficiency, the dsp digital signal processor controller is designed to adjust the stagger angle of igv automatically in order to optimize the efficiency at any operating condition. Based on practical experience and operational phenomena gas turbines. Development of measurement method for verification of multistage. There are two main types of compressors used in modern jet engines. An axial compressor is typically made up of many alternating rows of rotating and stationary blades called rotors and stators, respectively, as shown in figures 9. Pdf study the effect of variable vanes on performance of.
Incorrect operation of change setting system of va riable vaness could make unstable work of compressor and engine. Nasa technical note n o 04 cy n i z i 4 m 4 z nasa i tn d2962 cl i f noise studies of inletguidevanerotor interaction of a singlestage axialflow compressor langley reseurcb center lungley station, humpton, vu. Abstractthis paper presents a numerical methodology for optimizing a stator stagger setting in a multistage axial flow compressor environment. This paper reports a theoretical study of axial compressor surge. Moore cornell university ithaca, new york prepared for lewis research center under intergovernmental personnel agreement 8 1 o62 6 1 national aeronautics and space administration scientific and technical information branch 1983. Pdf structural and conceptual design analysis of an axial. Chapter 9 design and optimization of turbo compressors. In the case where flow passes through a straight pipe to enter a centrifugal compressor the flow is straight, uniform and has no vorticity, ie swirling motion, so the swirl angle.
The paper deals with problem influence of changes settings variable stator vanes axial compressor of gas turbine engine on work parameters of compressor and. An axialflow compressor compresses its working fluid by first accelerating the fluid and then diffusing it to obtain a pressure increase chapter 7. Introduction axialflow compressors are used in medium to large thrust gas turbine and jet engines. Sep 24, 1985 a device for attaching the stator vanes of an axial compressor to an external housing is disclosed. A theory of rotating stall of multistage axial compressors. Principal differences between the two types of impellers are size and ducting arrangement. Numerical optimization of a stator vane setting in. Aircraft gas turbine engine compressor section aircraft. Numerical optimization of a stator vane setting in multistage. Functions of compressor section of the aircraft gas turbine engine. Nasa technical note n o 04 cy n i z i 4 m 4 z nasa i tn d2962 cl i f noise studies of inletguidevanerotor interaction of a singlestage axial flow compressor langley reseurcb center lungley station, humpton, vu. Axial spacing of the blade rows is not considered, since it may be set based on stability or mechanical constraints. May 05, 2015 compressor performance has a large influence on total engine performance. What is the term used to describe the stationary vanes preceding the first stage of an axial compressor.
Compressor characteristic is relationship between compression ratio s, compressor efficiency. An axial compressor s performance curve can be changed by altering a variable inlet stator vane. The first stationary row which comes in front of the rotor is typically called the inlet guide vanes or igv. Blade vibratory stresses in a multistage axialflow. A variable angle stator vane 20 assembly for an axial flow gas turbine engine compressor. The stator vane spindle 36 extends through the housing bore 28. The paper deals with problem influence of changes s ettings variable stator vanes axial compressor of gas turbine engine on work parameters of compressor and engine. The first stationary row which comes in front of the rotor is typically called the inlet guide vanes or igv each successive rotorstator pair is called a compressor stage. Air flows axially into the compressor which has rotating blades on the discs and stationary vanes to direct the. However, unlike a propeller blade, the blades of an axial compressor are close to one another, which greatly alters the flow around each blade. Abstractthis paper presents a numerical methodology for optimizing a stator stagger setting in a multistage axialflow compressor environment. The stator vanes are usually made of steel with corrosion and erosionresistant qualities. Design and analysis of stator, rotor and blades of axial flow compressor.
As the flow passes through the centrifugal impeller, the impeller forces the flow to spin faster as it gets further from the rotational axis. The axial compressors are dynamic devices and in this, the flow of the gas is accelerated in a peripheral direction and also in the axial direction of the rotation of unique shaped blades. Ep0432885a1 mounting of adjustable stator vanes in an. Merchant marine exam third assistant engineer q533. One of the most important component in the modeling of a gas turbine is an axial compressor as in the first few stages involve variable vanes to regulate the. The air passing through the combustion chamber of a turbine engine is. Experimental investigation of the flow mechanisms and the. The casings of axialflow compressors not only support the stator vanes and provide the outer wall of the axial path the air follows, but they also provide the means for extracting compressor air for various purposes. Design calculation of blade design for axial flow compressor an axial flow compressor used in gas turbine engine has constant axial velocity throughout the compressor of 152 ms, blade mean velocity of 162 ms and it is delivered 10. A stator vane stage 54a in a splitcase, variable geometry axial flow compressor 30 includes two 180degree spokelike arrays of stator vanes 56 on upper and lower case halves 16,18 of the compressor case 12 and a pair of unitary, 180degree arc shroud ring segments 84,86. Both are shown in the adjacent photograph of an engine with 5 stages of axial compressor and one stage of centrifugal compressor. Structural and conceptual design analysis of an axial. Index terms compressor, naca, axial flow, rotor, stator i.
When in operation, axial compressors induce an inflow. In a stator less turbine the gas flow exiting an upstream rotor impinges onto a downstream rotor without an intermediate set of stator vanes that rearrange the pressurevelocity energy levels of the flow being encountered. Nonlinear aeromechanical behaviour of axial core compressor stator vanes. Figure 3 shows severe corrosion pitting of a 410 stainless steel variable inlet guide vane. The work produced by a turbine can be used for generating electrical power when combined with a generator.
The ind100 has a sixteen stage axial compressor and a vigv for part load operation, with a constant hub diameter annulus configuration and operating at isosls conditions as shown in figure 1. In an axial compressor, each blade on a rotor or stator produces a pressure variation much like a spinning propeller. An axial flow compressor is one in which the flow enters the compressor in an axial direction parallel. Axial flow compressor stators located in the casing as with other types of rotating machinery, an axial compressor can be described in a cylindrical coordinate system. Research and development of a high performance axial compressor. Design and analysis of stator, rotor and blades of the. Each stator vane 56 has a pivot shaft 64 at one end rotatably supported in a radial bore 70 in the.
Axial compressors an overview sciencedirect topics. This differs from other rotating compressors such as centrifugal compressor, axicentrifugal compressors and mixedflow compressors where the fluid flow will include a radial. The nonrotating axial flow compressor airfoils in an aircraft gas turbine engine, are called stator vanes the air passing through the combustion chamber of a turbine engine is. The variable stator vane gives the axial compressor, with its inherently steep pressure volume curve, the ability to be matched to a changing load without changing speed. Automatic efficiency optimization of an axial compressor with. Axialflow stage rotor and stator rows without case r fig. The compressor casing 23 has a bore 25 surrounded by a boss 24 at the position of each assembly. Variable stator vanes key words gas turbine engine, axial compressor, variable stator vanes. The first stationary row which comes in front of the rotor is.
Us4009969a supporting ring for stator vanes in an axial. Computational analysis and proposed redesign of the 3. Stator vane stage in axial flow compressor general. We performed investigations with both variable igv. Structural and conceptual design analysis of an axial compressor.
Stator blades permit the recovery of velocity to pressure. Pdf numerical optimization of a stator vane setting in multistage. The adjustable stators allow the stator to be positioned to the correct. A compressor stage is defined as a rotor blade row followed by a stator blade row. Most of the modern aircraft jet engines use variable stator vanes in both low pressure and high pressure compressors primarily for offdesign performance. Research and development of a high performance axial. Axial flow compressors are usually less forgiving than centrifugal compressors, thus more precision and accurate matching of rotor and stator flows are needed.
Pdf this paper presents a numerical methodology for optimizing a stator stagger setting in a multistage axialflow compressor environment. Automatic efficiency optimization of an axial compressor. Features of the existing compressor 10 3stage axial compressor with inlet guide vanes igvs and exit guide vane egvs. Axialflow compressors an overview sciencedirect topics. The fluid is accelerated by a row of rotating airfoils or blades the rotor and diffused by a row of stationary blades the stator. What is the key importance of variable stator vanes in an. These radial vanes, which may be straight for ease of manufacture, form divergent passages when mated with the compressor cases. Ep0545656a1 variable stator vane assembly for an axial. A theory of rotating stall of multistage axial compressors f. The stators can be carried by separate inner casings or by the outer. The igv and the first to third stage stator vanes were variable for which the angle can. Design and analysis of stator, rotor and blades of the axial.
336 441 1216 862 1198 1667 349 1595 151 1150 813 546 944 26 1118 1355 166 265 235 1600 445 1473 1256 1286 1634 1163 1187 424 1112 126 623 573 413 253 528 56 919 377 1210