Details
| Original language | English |
|---|---|
| Pages (from-to) | 297-307 |
| Number of pages | 11 |
| Journal | Energy conversion and management |
| Volume | 166 |
| Publication status | Published - 15 Jun 2018 |
Abstract
The ever-increasing demand for more efficient energy conversion has placed designers under increasing pressure to develop processing equipment that can meet contemporary needs. It has long been known that a decreasing Reynolds number has a negative effect on centrifugal compressor efficiency. The drop in efficiency can be accounted for relatively easily in the design process using various empirical correlations. However, the correlations only account for a reduction in performance; they do not offer any consideration of the extent to how the drop in efficiency can be countered in the design process. To identify potential methods by which it is possible to improve the performance of centrifugal compressors operating at low Reynolds numbers, the loss development in centrifugal compressors with a reducing Reynolds number must be studied. Recent works on loss development, in general, have focused on the overall performance deterioration, and the differentiation of the losses originating from different causes with the reducing Reynolds number has been studied only in an axial compressor. The present paper examines loss development in a centrifugal compressor with a vaneless diffuser with respect to the Reynolds number and differentiates between the losses that originate from different causes. A new hybrid method is used to calculate the boundary layer thickness inside a complex flow field. The results show that the diffuser plays a significant role in the performance deterioration of centrifugal compressors with a low Reynolds number and should be included in the loss development analysis. A study of the boundary layers, flow fields and loss development indicates that growth in the impeller hub and diffuser boundary layers should be reduced to improve the performance of the compressor.
Keywords
- Boundary layer thickness, CFD, Correction equation, Low Reynolds number, Tip clearance, Transition
ASJC Scopus subject areas
- Energy(all)
- Renewable Energy, Sustainability and the Environment
- Energy(all)
- Nuclear Energy and Engineering
- Energy(all)
- Fuel Technology
- Energy(all)
- Energy Engineering and Power Technology
Sustainable Development Goals
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In: Energy conversion and management, Vol. 166, 15.06.2018, p. 297-307.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Loss development analysis of a micro-scale centrifugal compressor
AU - Tiainen, Jonna
AU - Jaatinen-Värri, Ahti
AU - Grönman, Aki
AU - Fischer, Tore
AU - Backman, Jari
N1 - Funding Information: The authors would like to thank Michael Casey for the suggestion to study the influence of transitional turbulence modelling and would also like to acknowledge the financial contribution of the Academy of Finland. This research is part of the “Low-Reynolds number kinetic compression” project, which was funded by the Academy of Finland under Grant No. 274897 .
PY - 2018/6/15
Y1 - 2018/6/15
N2 - The ever-increasing demand for more efficient energy conversion has placed designers under increasing pressure to develop processing equipment that can meet contemporary needs. It has long been known that a decreasing Reynolds number has a negative effect on centrifugal compressor efficiency. The drop in efficiency can be accounted for relatively easily in the design process using various empirical correlations. However, the correlations only account for a reduction in performance; they do not offer any consideration of the extent to how the drop in efficiency can be countered in the design process. To identify potential methods by which it is possible to improve the performance of centrifugal compressors operating at low Reynolds numbers, the loss development in centrifugal compressors with a reducing Reynolds number must be studied. Recent works on loss development, in general, have focused on the overall performance deterioration, and the differentiation of the losses originating from different causes with the reducing Reynolds number has been studied only in an axial compressor. The present paper examines loss development in a centrifugal compressor with a vaneless diffuser with respect to the Reynolds number and differentiates between the losses that originate from different causes. A new hybrid method is used to calculate the boundary layer thickness inside a complex flow field. The results show that the diffuser plays a significant role in the performance deterioration of centrifugal compressors with a low Reynolds number and should be included in the loss development analysis. A study of the boundary layers, flow fields and loss development indicates that growth in the impeller hub and diffuser boundary layers should be reduced to improve the performance of the compressor.
AB - The ever-increasing demand for more efficient energy conversion has placed designers under increasing pressure to develop processing equipment that can meet contemporary needs. It has long been known that a decreasing Reynolds number has a negative effect on centrifugal compressor efficiency. The drop in efficiency can be accounted for relatively easily in the design process using various empirical correlations. However, the correlations only account for a reduction in performance; they do not offer any consideration of the extent to how the drop in efficiency can be countered in the design process. To identify potential methods by which it is possible to improve the performance of centrifugal compressors operating at low Reynolds numbers, the loss development in centrifugal compressors with a reducing Reynolds number must be studied. Recent works on loss development, in general, have focused on the overall performance deterioration, and the differentiation of the losses originating from different causes with the reducing Reynolds number has been studied only in an axial compressor. The present paper examines loss development in a centrifugal compressor with a vaneless diffuser with respect to the Reynolds number and differentiates between the losses that originate from different causes. A new hybrid method is used to calculate the boundary layer thickness inside a complex flow field. The results show that the diffuser plays a significant role in the performance deterioration of centrifugal compressors with a low Reynolds number and should be included in the loss development analysis. A study of the boundary layers, flow fields and loss development indicates that growth in the impeller hub and diffuser boundary layers should be reduced to improve the performance of the compressor.
KW - Boundary layer thickness
KW - CFD
KW - Correction equation
KW - Low Reynolds number
KW - Tip clearance
KW - Transition
UR - http://www.scopus.com/inward/record.url?scp=85045466903&partnerID=8YFLogxK
U2 - 10.1016/j.enconman.2018.04.014
DO - 10.1016/j.enconman.2018.04.014
M3 - Article
AN - SCOPUS:85045466903
VL - 166
SP - 297
EP - 307
JO - Energy conversion and management
JF - Energy conversion and management
SN - 0196-8904
ER -