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Computational Analysis of the Blade Loading on Tip Clearance Effects
Limin Wang
,
Yadong Liu
,
Chengqin Li
Issue: Volume 6, Issue 4, December 2020
Pages: 95-107
Received: 27 June 2020
Accepted: 26 October 2020
Published: 16 November 2020
DOI:
10.11648/j.ijfmts.20200604.11
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Abstract: Gas turbines normally have the rotating and stationary parts. The rotational blades always need clearance to rotation. Blade tip clearance is one of the important parameters affecting performance, safety and stability of a gas turbine engine. However, it is difficult to measure the tip clearance accurately during the tests. The numerical studies are important methods to study the tip clearance effects. Tip clearance effects have been studied for a long time. However, there are still many aspects that are not fully understood and industries still don’t have a good way to perform design with minimum tip clearance losses. In the gas turbine design, the tip clearance considerations are very critical for both performance and reliability. In this paper, we perform the numerical study on the tip clearance impacts during the aerodynamic design, especially the blade loading through blade counts. The study found that the proper blade loading could reduce the tip clearance sensitivity and reduce the tip clearance losses. In the cases of reasonable number of blades, the effect of clearance on the total pressure loss and efficiency had a linear relationship. But in the cases of small number of blades, the effect of clearance on the total pressure loss and efficiency is no longer linear. The study helped turbine designers to consider blade loading and tip clearance together during the turbine design.
Abstract: Gas turbines normally have the rotating and stationary parts. The rotational blades always need clearance to rotation. Blade tip clearance is one of the important parameters affecting performance, safety and stability of a gas turbine engine. However, it is difficult to measure the tip clearance accurately during the tests. The numerical studies ar...
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A Novel Viscous Throughflow Model for Compressor Analysis and Its Application
Hailiang Jin
,
Daobin Qiu
,
Yueqian Yin
Issue: Volume 6, Issue 3, September 2020
Pages: 89-94
Received: 12 July 2020
Accepted: 25 August 2020
Published: 07 September 2020
DOI:
10.11648/j.ijfmts.20200603.13
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Abstract: Throughflow calculations are still an inevitable step in the aerodynamic design of compressors. The viscous throughflow model derived from Navier-Stokes equations can be more capable in predicting choked flow and capturing shock waves compared to the traditional methods. In this paper, authors further developed the inviscid model for a previously developed throughflow analysis method. To obtain the governing equations, three-dimensional Navier-Stokes equations combined with the Spalart-Allmaras turbulence model were circumferentially averaged with the assumption that the flow was circumferentially uniform. A viscous blade force and an inviscid blade force had been calculated. The Miller's correlations of deviation angle and loss were incorporated to model these forces. The governing equations are discretized by an explicit four-step Runge-Kutta scheme and solved by a time-marching finite volume method. Current model was verified through predicting the performances of a 1.5 stage fan. The agreements between the experiments and calculations are reasonably good. This throughflow model can predict quite similar flow patterns and radial profiles of some parameters compared to a CFD software, which shows the potential of this model. There are still some notable deviations between the results from throughflow analysis and that from CFD calculation. Future work is to improve the prediction of deviation angle and loss near the endwall regions.
Abstract: Throughflow calculations are still an inevitable step in the aerodynamic design of compressors. The viscous throughflow model derived from Navier-Stokes equations can be more capable in predicting choked flow and capturing shock waves compared to the traditional methods. In this paper, authors further developed the inviscid model for a previously d...
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Computational Investigation of Flow in a Centrifugal Impeller with Chamfered Blade Tips: Effects of Stage Loading and Tip Clearance
Nekkanti Sitaram
,
Vanamala Ushasri
Issue: Volume 6, Issue 3, September 2020
Pages: 79-88
Received: 18 May 2020
Accepted: 13 July 2020
Published: 13 August 2020
DOI:
10.11648/j.ijfmts.20200603.12
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Abstract: The objective of the present investigation is to examine the possibility of performance improvement, improvement of the exit flow uniformity and desensitization of the tip clearance effects on the performance of a low speed centrifugal impeller. Computational investigations using a commercial CFD software are undertaken. Six configurations of blade tips are investigated. They are square tip (Basic), tip chamfered on pressure surface (P1 and P2), tip chamfered on suction surface (P1 and P2) and tip chamfered on pressure and suction surfaces (PS1). Computations are carried out with optimized multiblock grids for these six configurations at five flow coefficients, namely 0.28 and 0.34 (below design flow coefficient), 0.42 (design flow coefficient) and 0.48 and 0.52 (above design flow coefficient) and at three values of tip clearance, viz., 1% (small value), 2% (nominal value) and 5% (large value) of the blade exit height. From the investigations, it is found that the impeller with the chamfer on suction surface shows small improvement in performance. In addition this configuration has minimum tip clearance sensitivity. A decrease in the chamfer on suction surface further may improve the impeller performance. A maximum percentage of 0.18% improvement in the total pressure coefficient is obtained at 5% tip clearance and a flow coefficient of 0.52 for configuration S2. However chamfer on the pressure surface deteriorates the impeller performance.
Abstract: The objective of the present investigation is to examine the possibility of performance improvement, improvement of the exit flow uniformity and desensitization of the tip clearance effects on the performance of a low speed centrifugal impeller. Computational investigations using a commercial CFD software are undertaken. Six configurations of blade...
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The Development of High Efficiency Integrally Geared Driven Multistage Centrifugal Compressor
Leilei Han
,
Fubao Li
,
Ning Li
,
Haiyang Zhou
,
Lihui Jiang
,
Zongyang Wang
Issue: Volume 6, Issue 2, June 2020
Pages: 53-60
Received: 23 April 2020
Accepted: 02 June 2020
Published: 28 June 2020
DOI:
10.11648/j.ijfmts.20200602.12
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Abstract: Integrally geared multistage centrifugal compressors have been widely used in many industries. The design of the new compressor is very complicated and needs a reliable design process. This paper discussed the development of a high efficiency integrally geared driven centrifugal compressor for industrial applications. An inhouse program was used to design the centrifugal compressor through aerodynamic and structural optimization. CFD (Computational Fluid Dynamics) is a very important tool for centrifugal compressor design. CFD can help compressor design and perform three-dimensional optimization to further optimize the compressor. The compressor stage matching is also impact the overall compressor performance. The good stage match is very important to make the design success. The Finite Element Analysis (FEA) was used to verify the structure integrity. The CFD and FEA (Finite Element Analysis) analysis are performed to obtain a final compressor performance and to make sure to have a robust operation. The centrifugal compressor has the characteristics of high efficiency, no resonance, and low noise. The designed compressor prototype was built and performance tests were conducted. The performance test results demonstrated that the analytical are fairly agreed with experimental results. The development process and tools are successfully used in the compressor design. The design process can be used for future compressor development.
Abstract: Integrally geared multistage centrifugal compressors have been widely used in many industries. The design of the new compressor is very complicated and needs a reliable design process. This paper discussed the development of a high efficiency integrally geared driven centrifugal compressor for industrial applications. An inhouse program was used to...
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The Recent Progresses in Industrial Centrifugal Compressor Designs
Dingkun Liang
,
Hanqian Yang
,
Cheng Xu
,
Yandan Jiang
,
Zhongwei Yi
Issue: Volume 6, Issue 2, June 2020
Pages: 61-69
Received: 17 May 2020
Accepted: 28 May 2020
Published: 28 June 2020
DOI:
10.11648/j.ijfmts.20200602.13
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Abstract: The centrifugal compressor has been widely used in low power gas turbine, supercharger and industrial turbine compressors. Due to its outstanding advantages of simple process, compact structure and wide working range, it is more advantageous in some aspects such as small flow range than counterparts. However, the design of important components of centrifugal compressor requires lots of design experience and consideration. Because of the deepening research of the industrial centrifugal compressor, some excellent design optimization methods and experiences are obtained from researchers. In order to enable designers to get the preliminary design parameters and to develop a compressor with better performance better and faster, this paper addresses the main design optimization methods and design experiences of the components of the industrial centrifugal compressor. The detailed design considerations and design process for centrifugal compressor can reduce the design cycle time without scarifying performance for the new design. The purpose of this paper is to provide some design considerations and experiences of the centrifugal compressor for researchers. According to the centrifugal compressor design optimization process, purposed considerations in this paper are useful for compressor preliminary parameters selections. The optimizations and design considerations in this paper provide a detailed reference document for future centrifugal compressor developments.
Abstract: The centrifugal compressor has been widely used in low power gas turbine, supercharger and industrial turbine compressors. Due to its outstanding advantages of simple process, compact structure and wide working range, it is more advantageous in some aspects such as small flow range than counterparts. However, the design of important components of c...
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Design of a Radial Turbine for Wastegated Turbocharger
Hanqin Yang
,
Qingbin Li
,
Liaoping Hu
,
Xiong Meng
,
Guangqing He
,
Lin Liu
Issue: Volume 6, Issue 1, March 2020
Pages: 19-26
Received: 28 January 2020
Accepted: 21 February 2020
Published: 28 February 2020
DOI:
10.11648/j.ijfmts.20200601.13
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Abstract: With the increasing popularity of turbocharging technology in the automotive industry, and people's increasing awareness of environmental protection, engineers are paying more attention to the technical development of turbochargers, while more advanced tools and methods are being used in the actual turbocharged design process to improve the accuracy and efficiency of research and design. Traditional turbocharger design methods are often based on experimental data and empirical models, and long development cycles conflict with market demand, and high performance conflict with high reliability. In this paper, in order to resolve this significant contradiction, a design process based on a variety of CAE methods and tools is proposed for the design of turbines, which are key components of turbochargers. This process was early applied to the design of turbocharger compressor, and then under the original boundary conditions, considering the challenges of high temperature and high engine demand, it has been improved and applied to the design of a 9L off-road country Tier-IV engine turbine in the Chinese market. The analysis shows that the turbine has good aerodynamic performance and structural reliability. The turbine performance was tested in gas stand the also verified on the engine test. This study demonstrated that the design was successful and future new turbine design can use similar procedure.
Abstract: With the increasing popularity of turbocharging technology in the automotive industry, and people's increasing awareness of environmental protection, engineers are paying more attention to the technical development of turbochargers, while more advanced tools and methods are being used in the actual turbocharged design process to improve the accurac...
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Design System Development for a Fuel Cell Centrifugal Compressor
Cheng Xu
,
Lei Chen
,
Ryoichi Amano
Issue: Volume 5, Issue 4, December 2019
Pages: 96-101
Received: 22 September 2019
Accepted: 22 October 2019
Published: 05 November 2019
DOI:
10.11648/j.ijfmts.20190504.12
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Abstract: Centrifugal compressors have been used in many areas of the machinery. The centrifugal compressor design is very complex, and a unique design system needs to be developed. A centrifugal compressor design system should be easy to use in interface and also flexible for inputs and outputs. The design tool also needs to be able to predicate the compressor performance in a fairly accurate level. In this study, a centrifugal compressor design system which was developed in the past is further improved and developed. Current design system includes initial parameter studies, meanline analysis, throughflow calculation, impeller design, diffusser design, volute design, and structure analysis. The main improvements of the design system are adding the interface to allow users easy to use, adding the input and output capabilities and modifying few correlations. Current design system can predict the blade loading and compressor performance better compared with original design system. A fuel cell low flow and low specific speed centrifugal compressor is designed by using current design system and the prototype compressor is built. The compressor performance tests were conducted. The experimental results are compared with numerical analysis. The experiments are in good agreements with calculations. The results demonstrate that the centrifugal compressor design is successful and the design system can be used for the future centrifugal compressor designs.
Abstract: Centrifugal compressors have been used in many areas of the machinery. The centrifugal compressor design is very complex, and a unique design system needs to be developed. A centrifugal compressor design system should be easy to use in interface and also flexible for inputs and outputs. The design tool also needs to be able to predicate the compres...
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Research on Flow Characteristics of Upstream Cavity with Labyrinth Seals in Axial Compressor
Xin Fu
,
Yingying Xu
,
Yan Zhang
Issue: Volume 5, Issue 3, September 2019
Pages: 82-90
Received: 13 July 2019
Accepted: 10 September 2019
Published: 23 September 2019
DOI:
10.11648/j.ijfmts.20190503.14
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Abstract: The sealing between rotating components and stator components has become one of the main issues to be studied in the compressor. The mixing of stator root leakage flow and the mainstream can seriously affect the performance of the compressor. This article does a series of work on numerical calculation of plane diffuser cascade with the stator cavity and three-stage labyrinth seal. It also analyzes the details of the flow structure on upstream cavity. In this paper, the 3D streamlines distribution of the cascade corner region is studied, respectively for the no leakage case and the mixing mechanism of the secondary flow and mainstream with leakage. On this basis, the upstream cavity configuration is optimized and some results are obtained as fellows. The mainstream in the blade leading edge into the upstream cavity comes into being the secondary flow, which similar to leakage flow. It can affect the highest 80% leaves of the high range. Leakage flow is mainly influence on the performance of the blade root flow field and weakly of next to casing area. Compared to no leakage case, angular separation position ahead of time and range increased when there is leakage. Thus, added rib on both sides of the vessel wall can reduce the total pressure loss of the S3 section, and the relative position of ribbed effect significantly. The research shows that first layer of rib is better when set on the hub wall surface, the total pressure loss coefficient decreased by 3.49%.
Abstract: The sealing between rotating components and stator components has become one of the main issues to be studied in the compressor. The mixing of stator root leakage flow and the mainstream can seriously affect the performance of the compressor. This article does a series of work on numerical calculation of plane diffuser cascade with the stator cavit...
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