scholarly journals Numerical Investigation of the Flow Field and Aerodynamic Load on Impellers Under Radial Inlet Guide Vanes With Trailing Edge Blowing in Centrifugal Compressor

2021 ◽  
Vol 1081 (1) ◽  
pp. 012040
Author(s):  
Jianchi Xin ◽  
Haitao Liu ◽  
Zhitao Tian ◽  
Xiangyang Liu ◽  
Xiaozhi Kong ◽  
...  
2016 ◽  
Vol 33 (2) ◽  
Author(s):  
WANSHI QU ◽  
lei tan ◽  
Shuliang CAO ◽  
YUCHUAN WANG ◽  
YUN XU

Purpose The paper aims to investigate the clocking effect on a centrifugal pump with inlet guide vanes (IGVs). Design/methodology/approach The paper uses a computation fluid dynamics (CFD) framework to solve the unsteady flows in a centrifugal pump with inlet guide vanes. The relative position between the stationary vanes and the stationary volute tongue is defined as the clocking position when IGVs inside the suction pipe rotate along the circumferential direction. Findings The results show that clocking positions have little effect on the pump head and efficiency, however their influences are obvious for the pressure fluctuation and flow field in the centrifugal pump. The maximum difference of pressure amplitude at dominant frequency reach up to 28% on the monitoring point V8 at different clocking positions under design flow rate. For the large flow rate, the clocking effect on flow field and pressure fluctuation in centrifugal pump is similar to that of design flow rate. However, the clocking effect is nearly negligible at partial flow rate, because there are reverse flows around the tongue tip and obvious vortexes forming and developing in the impeller. Those complex phenomena interacting in the centrifugal pump make the clocking effect less evident. Originality/value The numerical investigation reveals the clocking effect on a centrifugal pump with inlet guide vanes, which also valuable for the stable operation and optimal design of centrifugal pumps.


Author(s):  
Michael M. Cui

Suction elbows and inlet guide vanes (IGVs) are typical upstream components in front of first-stage impellers in centrifugal compressors. The three-dimensional distortion induced by elbows and IGVs affects the flow field behind the IGV housing. Since the flow field in front of the impeller is subsonic, the flow motion induced by the rotating impeller will interact with the elbow and IGVs as well. The flow field resulting from these interactions is three-dimensional. The nature of this flow field defines design requirements of upstream components and impact overall performance of the compressor. To understand the mechanism controlling the interactions of up-steam components and optimize the compressor design for better efficiency and reliability, a numerical simulation of the flow field inside the entire first stage of the compressor was conducted. The stage studied includes suction elbow, IGV housing with vanes, and first-stage impeller. HFC 134a was used as the working fluid. The thermodynamic and transport properties of the refrigerant gas were modeled by the Martin-Hou equation of state and power laws respectively. The three-dimensional flow field was simulated with a Navier-Stokes solver using the k-ε turbulence model. The overall performance parameters are obtained by integrating the field quantities. The force, torque, and arm of moment acting on the IGVs were then calculated. The results can be used to improve centrifugal compressor design to achieve higher efficiency and improve reliability. The methodology developed in the current study can be applied to centrifugal compressor design and optimization.


Author(s):  
Michael M. Cui

A suction elbow and inlet guide vanes (IGVs) are typical upstream components in the front of the first-stage impeller in a centrifugal compressor. Since the flow field in the front of the impeller is subsonic, the flow motion induced by the rotating impeller interacts with the elbow and IGVs. These interactions induce turbulent unsteady flows inside compressors. The resulted unsteadiness affects efficiency, vibration, and noise generation of the compressor. To understand the mechanism controlling the interactions between up-steam components and to optimize the compressor design for better efficiency and reliability, the turbulent unsteady flow inside the first-stage of the compressor was simulated. The model includes the suction elbow, inlet guide vane housing, and first-stage impeller. HFC 134a was used as the working fluid. The thermodynamic and transport properties of the refrigerant gas were modeled by the Martin-Hou equation of state and power laws, respectively. The three-dimensional unsteady flow field was numerically simulated. The overall performance parameters were obtained by integrating the field quantities. The force, torque, and the arm of moments acting on the IGVs are then calculated. The results can be used to improve centrifugal compressor design to achieve higher efficiency and improve reliability.


Author(s):  
Ronald P. Porter

A high efficiency, low cost gas compressor is under development. Design has been completed and fabrication is in process. The manufacturer’s background in centrifugal compressor design and current methodology is discussed along with product definition. Assembly and test of the first unit is planned for summer 1996. The design features a single-stage overhung centrifugal compressor, variable inlet guide vanes, and dry gas seals.


2020 ◽  
Vol 12 (11) ◽  
pp. 168781402097490
Author(s):  
Fenghui Han ◽  
Zhe Wang ◽  
Yijun Mao ◽  
Jiajian Tan ◽  
Wenhua Li

Inlet chambers (IC) are the typical upstream component of centrifugal compressors, and inlet guide vanes in the IC have a great impact on its internal flow and aerodynamic loss, which will significantly influence the performance of the downstream compressor stages. In this paper, an experimental study was carried out on the flow characteristics inside a radial IC of an industrial centrifugal compressor, including five testing sections and 968 measuring points for two schemes with and without guide vanes. Detailed distributions of flow parameters on each section were obtained as well as the overall performance of the radial IC, and the causes of the flow loss inside the IC and the non-uniformity of flow parameters at the outlet section were investigated. Besides, numerical simulations were performed to further analyze the flow characteristics inside the radial IC. The experimental and numerical results indicate that, in the scheme without guide vanes, sudden expansions in the spiral channel and flow separations in the annular convergence channel are the major sources of flow loss and distortions generated in the radial IC; while in the scheme with guide vanes, the flow impacts, separations and wakes caused by the inappropriate design of guide vanes are the main reasons for the flow loss of the IC itself and the uneven flow distributions at the IC outlet.


2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Yohan Jung ◽  
Minsuk Choi ◽  
Seonghwan Oh ◽  
Jehyun Baek

This paper presents a numerical investigation of the effects of a nonuniform tip clearance profile on the performance and flow field in a centrifugal compressor with a vaneless diffuser. This study focuses in particular on the magnitude and location of the wake. Six impellers with different tip clearance profiles were tested in the flow simulations. The accuracy of the numerical simulations was assessed by comparing the experimental data with the computational results for a system characterized by the original tip clearance. Although the performance improved for low tip clearances, a low tip clearance at the trailing edge improved the compressor performance more significantly than a low tip clearance at the leading edge. The flow field calculated for a system characterized by a low tip clearance at the trailing edge produced a more uniform velocity distribution both in the circumferential and in the axial directions at the impeller exit because the wake magnitude was reduced. As a consequence, this impeller provided a better potential for diffusion processes inside a vaneless diffuser.


1996 ◽  
Author(s):  
Michael D. Hathaway ◽  
Jerry R. Wood

CFD codes capable of utilizing multi-block grids provide capability to analyze the complete geometry of centrifugal compressors including, among others, multiple splitter rows, tip clearance, blunt trailing edges, fillets, and slots between moving and stationary surfaces. Attendant with this increased capability is potentially increased grid setup time and more computational overhead — CPU time and memory requirements — with the resultant increase in “wall clock” time to obtain a solution. If the increase in “difficulty” of obtaining a solution significantly improves the solution from that obtained by modeling the features of the tip clearance flow or the typical bluntness of a centrifugal compressor’s trailing edge, then the additional burden is worthwhile. However, if the additional information obtained is of marginal use then modeling of certain features of the geometry may provide reasonable solutions for designers to make comparative choices when pursuing a new design. In this spirit a sequence of grids were generated to study the relative importance of modeling versus detailed gridding of the tip gap and blunt trailing edge regions of the NASA large low speed centrifugal compressor for which there is considerable detailed internal laser anemometry data available for comparison. The results indicate: 1) There is no significant difference in predicted tip clearance mass flow rate whether the tip gap is gridded or modeled. 2) Gridding rather than modeling the trailing edge results in better predictions of some flow details downstream of the impeller, but otherwise appears to offer no great benefits. 3) The pitchwise variation of absolute flow angle decreases rapidly up to 8% impeller radius ratio and much more slowly thereafter. Although some improvements in prediction of flow field details are realized as a result of analyzing the actual geometry there is no clear consensus that any of the grids investigated produced superior results in every case when compared to the measurements. However, if a multi-block code is available it should be used as it has the propensity for enabling better predictions than a single block code which requires modeling of certain geometry features. If a single block code must be used some guidance is offered for modeling those geometry features which can’t be directly gridded.


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