The model was well correlated with experimental modal analysis test results. Pdf the present study focuses on the aerodynamic performance and structural analysis of the centrifugal compressor impeller. Aerodynamic synthesis of a centrifugal impeller using cfd. But there is some slip between the impeller and the. Optimal design of a centrifugal compressor impeller using. The chemical composition analysis of the failed impeller using the quantometer shows that it is similar to astm a514 steel, grade f, as shown in table 1. Centrifugal compressor surge, modeling and identification for. The interaction between impeller and diffuser in a highpressure ratio centrifugal compressor is considered to have a strong influence on the unsteady flow field, the impeller response and the performance of the compressor. The side cavities are the spaces between the casing and the sketched impeller s hub and shroud. High speed centrifugal impeller and diffuser interaction near. Forced response of a centrifugal compressor stage due to the. Table 1 and figure 3 show the main specifications and forms of the two optimized design impellers opt1 and opt2, and a baseeline impeller, respectively. Impact of magnetic suspension stiffness on aeroelastic compressor. On a compressor performance map, instead of just the characteristic curve, operation in the entire region below it is required to cover the large variation in weather and cooling demand conditions.
Army research laboratory nasa lewis research center cleveland, oh 445 and p. These features makes the blades more susceptible to aeroelastic problems, such as flutter, a. Impeller is an active part that adds energy to the fluid, its. This article presents a study of the effect of a contrarotating component on the efficiency of centrifugal compressors. Msi was contracted by a customer to investigate a series of blade cracking problems in a compressor impeller. A centrifugal compressor is usually used for a turbo chiller. Symposium on unsteady aerodynamics, aeroacoustics and aeroelasticity of. Development of highefficiency centrifugal compressor for. Bulkflow analysis for force and moment coefficients of a shrouded centrifugal compressor impeller. Visual inspections after the compressor disassembling and the rotor removal, it was evident that the second stage impeller was catastrophically broken. The side cavities are the spaces between the casing and the sketched impellers hub and shroud. This manual does not for designing centrifugal compressor and those parts.
Unsteady aerodynamics and aeroelasticity of turbomachines proceedings of the 8 1h international symposium held in stockholm, sweden, 14. Pdf aerodynamic and structural characteristics of a. Centrifugal compressors dynamic considerations for station design. As we have already noted in the centrifugal pump, this results in a higher static pressure on the leading face. A centrifugal compressor having design pressure ratio of 4. A study on fluid selfexcited flutter and forced response of. Impeller high cycle fatigue failure on a natural gas. Scribd is the worlds largest social reading and publishing site. Aerodynamic design of centrifugal compressor for at14.
Pdf aerodynamic and structural characteristics of a centrifugal. Aerodynamic design studies of a transonic centrifugal compressor. Development of endoscopic stereoscopic piv to investigate the igv impeller interaction in a centrifugal compressor. The radial gap ratio between the impeller and the diffuser vanes plays an important role in the.
To help achieve these goals, manufacturing technologies for the disks, airfoils, and impellers in the compressors of these advanced. Analysis and optimization of aerodynamic noise in a centrifugal compressor hyosung sun, hyungki shin, soogab lee center for environmental noise and vibration research, school of mechanical and aerospace engineering, seoul national university, san 561, shinlimdong, kwanakgu, seoul 151742, korea. Chapter 5 centrifugal pump impeller vane profile the concept of impeller design and the application of inverse design for the vane profile construction are discussed in this chapter. An investigation of impeller and diffuser interaction in a transonic centrifugal compressor, unsteady aerodynamics and aeroelasticity of turbomachines, 1995, pp. In this work, a frequency domain, harmonic balance cfd code is used to analyze a 3. An impeller blade analysis of centrifugal gas compressor. Bpf blade passing frequency k specific turbulent kinetic energy. Experimental studies on the improvement potential of a centrifugal compressor stage with different spiral geometries. An optimization technique for radial compressor impellers michael casey, frank gersbach itsm institute of thermal turbomachinery and machinery laboratory, universitat stuttgart,pfaffenwaldring 6, d70569 stuttgart, germany email. The instability is characterized by large limit cycle oscillations in compressor. Childs an analysis is developed for a compressible bulkflow model of the leakage path. Impeller blade of centrifugal compressor 3 figure 1 shows the sketch of a rotating impeller that imparts a high velocity to the fluid, and a number of fixed diverging passages in which the fluid is decelerated with a consequent rise in static pressure in the plenum. Each stage typically consists of an impeller rotating element and a diffuser stationary element.
The cad model of the compressor impeller is shown in fig. Final report ncc3719 centrifugal compressor aeroelastic. Ncc3719 centrifugal compressor aeroelastic analysis code submitted to national aeronautics and space administration glenn research center at lewis field cleveland, ohio dr. This paper presents optimal aerodynamic consideration on impeller, diffuser and volute for a mems centrifugal compressor. An optimization study was conducted on a centrifugal compressor. Hightemperature compressor material development the next generation of subsonic commercial aircraft will require engines with improved efficiency and greater durability at lower costs. Cfdaided design of a transonic aeroelastic compressor rig. Performance enhancement of centrifugal compressors utilizing. The impellers have been constructed by welding the blades to the cover, and all of these parts were made by forging. A computational model of a centrifugal compressor stage for aircraft engines ing. Osman khan, phd, pe, consultant mechanical engineering dept. Aerodynamic design of centrifugal compressor free download as powerpoint presentation. The aerodynamics of the inlet of centrifugal compressor.
The impeller represented as a plain aluminum disk is embraced by a plain walled casing. Manual on aeroelasticity in axialflow turbomachines, vol. Eight design variables were chosen from the control points for the bezier curves which widely influenced the geometric variation. Also, the composition and mole fraction of the inlet gas to the compressor are illustrated in table 2. Performance enhancement of centrifugal compressors. Pdf high speed centrifugal impeller and diffuser interaction near stall conditions. Chris robinson pca engineers limited, homer house, sibthorp street. Aerodynamics and aeroelasticity of impeller vane interactions. Dec 22, 2010 the interaction between impeller and diffuser in a highpressure ratio centrifugal compressor is considered to have a strong influence on the unsteady flow field, the impeller response and the performance of the compressor. An optimization technique for radial compressor impellers. An fea model of the impeller was created to perform a natural frequency modal analysis. Highperformance centrifugal compressors call for a reduction in weight to relax rotor. What is the difference between axial and centrifugal compressors.
A mechanical stress optimization of the impeller is planned for the near future. Fig 2 centrifugal compressor fig 3 velocities triangle evolution with preswirl. Numerical studies on the effect of impeller blade skew on. Optimized design results of centrifugal compressor impeller the centrifugal compressor impeller is a backswept open impeller type with a splitter blade, and the design pressure ratio is 1. Numerical simulation of welding deformation produced in. Forced response analyses are carried out on the embedded rotors at different crossings on the campbell diagram. A contrarotating centrifugal compressor crcc is constructed using two independent rotors, rotating in the opposite direction and replacing the single rotor of a conventional centrifugal compressor ref. A compressor component stalls if it is operated too far away from its design point stall in centrifugal compressors usually occurs in the diffuser, or in the inducer part of the impeller it often is present as rotating stall, i.
Jp, manager, turbo machinery and engine technology. It is wellknown that aerodynamic matching of impeller, diffuser and volute controls total performance of centrifugal compressor. Effects of air injection on a centrifugal compressor performance are studied numerically and results are presented in this paper. Among the components of the centrifugal compressor, the impeller is a pivotal part as it is used to transform kinetic energy into pressure energy.
The impeller adds kinetic energy to the fluid in the same way the blades of a household fan do, although the cen. In this analysis, heat source length was 6 mm, and thermal efficiency was 0. A computational model of a centrifugal compressor stage for. Case study failure analysis of a compressor impeller. The assessments focus on the forced response of two splitter blade modes to a variety of representative boundary conditions and unsteady loadings.
Flow field is simulated based on solution of the reynoldsaveraged navierstokes equations utilizing the wellknown k. According to their analysis the shroud disk of a radial fan impeller failed due to aeroelastic selfexcitation. Conceptual design and performance prediction of gas pipeline. The range of application the compressor on a water chiller is usually extremely large 1. The vane profile plays a vital role to develop the streamlined flow. Unsteady aerodynamics and aeroelasticity of turbomachines. Multistage centrifugal compressor modifications and rerates replace isocarbon or isosleeve seals with dry gas seals s upgrade coupling from lubricated to drytype n add or upgrade machinery performance, diagnostic, and protective instrumentation nreplace isocarbon or l add oil wash spray nozzles n replace impeller and shaft. Analysis and optimization of aerodynamic noise in a. Unsteady aerodynamics and aeroelasticity of turbomachines proceedings of the 8 1h international symposium held in stockholm, sweden, 1418 september 1997 edited by torsten h. A full twoway coupling aeroelasticity analysis of rotating. Conceptual design and performance prediction of gas pipeline centrifugal compressors m dosanjh bg transco, a whitfielduniversity of bath and a zohrabian bg transco abs1ract the operating requirements of gas pipeline centrifugal compressors can change over the working life of the. Sep 23, 2019 centrifugal compressors centrifugal compressors typically consist of one or more stages.
Chemical composition of the impeller composition impeller astm a514 steel, grade f. Performance enhancement of centrifugal compressors utilizing impeller tip injection volume 32 issue 4 r. They are marked green and blue in figure 1, respectively. No aeroelastic instability predicted for suspected impeller natural mode.
Rakesh srivastava senior research associate department of mechanical industrial and manufacturing engineering. Pdf effects of radial gap ratio between impeller and vaned. Aerodynamic design optimization of centrifugal compressor. The impeller of a natural gas pipeline compressor failed at the junction between the blade trailing. Completed projects in the centrifugal compressor area. Afshari skip to main content accessibility help we use cookies to distinguish you from other users and to provide you with a better experience on our websites. The influence of aeroelastic effects on the impeller and the rotor on the. Brook park, oh 44142 abstract the performance and flow structure in an unshrouded impeller of approximately 4. The goal is to analyze the effect of neighboring rows on the response amplitude of the embedded rotors. Service multistage centrifugal compressor modifications and. Analysis of metallurgical and mechanical failure of a. Manual purpose to be used for selection, application into the system, power and cooling water estimation. There are few systematic works concerning to aerodynamic matching of.
1097 1078 1554 222 1598 224 754 232 809 1363 1398 750 248 752 286 1025 414 388 445 1374 441 118 660 485 1551 1225 1121 320 125 1118 1083 939 1585 1174 631 968 36 489 1099 1334 1151 1060 1252 736 756 888 815 1494 774 996