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RISS 인기검색어
- 검색키워드
- 저자 : Ahmed Kovacevic (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
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Review of Mathematical Models in Performance Calculation of Screw Compressors
Stosic, Nikola,Smith, Ian K.,Kovacevic, Ahmed,Mujic, Elvedin Korean Society for Fluid machinery 2011 International journal of fluid machinery and syste Vol.4 No.2
The mathematical modelling of screw compressor processes and its implementation in their design began about 30 years ago with the publication of several pioneering papers on this topic, mainly at Purdue Compressor Conferences. This led to the gradual introduction of computer aided design, which, in turn, resulted in huge improvements in these machines, especially in oil-flooded air compressors, where the market is very competitive. A review of progress in such methods is presented in this paper together with their application in successful compressor designs. As a result of their introduction, even small details are now considered significant in efforts to improve performance and reduce costs. Despite this, there are still possibilities to introduce new methods and procedures for improved rotor profiles, design optimisation for each specified duty and specialized compressor design, all of which can lead to a better product and new areas of application. A review of methods and procedures which lead to modern screw compressor practice is presented in this paper. This paper is intended to give a cross section through activities being done in mathematical modelling of screw compressor process through last five decades. It is expected to serve as a basis for further contributions in the area and as a challenge to the forthcoming generations of scientists and engineers to concentrate their efforts in finding future and more extended approaches and submit their contributions.
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Numerical Investigation on a Twin-Screw Multiphase Pump Under low IGVF
Shuaihui Sun,Pengbo Wu,Pengcheng Guo,Guangzhi Yi,Ahmed Kovacevic 한국유체기계학회 2021 International journal of fluid machinery and syste Vol.14 No.4
A three-dimensional transient numerical model was developed to obtain the two-phase flow characteristics in a twin-screw multiphase pump based on dynamic mesh technology and the multiphase flow model. The pump performance under different inlet gas volume fractions (IGVF) was predicted by the numerical model and was tested. Then, the numerical model was validated after comparing the simulation and experimental results. After that, the flow field in the pump under 10% IGVF was analyzed. When the IGVF is 10%, the pressure increases step by step and is symmetrical from both ends to the middle of the screw rotors. The pressure distribution through a single working chamber is uniform. It falls rapidly at the inlet of the tooth tip gap and then drops linearly in the gap channel. At the outlet of the tip gap, the pressure temporarily falls due to the high-speed jet. The GVF distribution in the working chamber is uneven. The leakage flow is laminar in the tip gap, and the liquid concentrates on the top of the gap. When the last working chamber connects with the discharge chamber, the discharge jet flow causes the vortices in the discharge pipe. The gas gradually moves to the center of the vortices, forming four gas-phase aggregation regions. The velocity of the interlobe leakage is the largest. The maximum velocity appears at the second cross-section and reaches 35m/s. This research can be used to improve the performance of the twin-screw multiphase pump under two-phase working conditions.
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