Computational Fluid Dynamics Studies on a Centrifugal Compressor Stage with Twisted Vanes of a Low Solidity Diffuser

Venkateswara Rao, P.; Govindaraju, V. R.; Venkateswarlu, K.; Bhanu Kumari, M.

doi:10.47176/jafm.18.9.3209

Computational Fluid Dynamics Studies on a Centrifugal Compressor Stage with Twisted Vanes of a Low Solidity Diffuser

Document Type : Regular Article

Authors

¹ Department of Mechanical Engineering, Vasavi College of Engineering, Hyderabad, Telangana, India

² Turbomachinary, BHEL, Vikasnagar, Hyderabad 500093, India

³ Mechanical and Metallurgical Engineering, School of Engineering and the Built Environment, JEDS Campus, University of Namibia, Private Bag 3624, Ongwediva, Namibia

⁴ Department of Mathematics, Lords College of Engineering and Technology, Hyderabad, India

10.47176/jafm.18.9.3209

Abstract

This study examines the effect of a twisted diffuser vane on the performance of a centrifugal compressor stage. A computational analysis was conducted to assess how the setting and twist angles influence the compressor’s performance and diffuser static pressure recovery (SPR). The diffuser vane was modeled using a standard aerofoil design with minor adjustments to the trailing edge. A twisted diffuser blade was created by varying the twist angle from hub to shroud, which results in different stagger angles. Three types of diffusers—vaneless, low solidity vaned, and twisted vaned—were analyzed across five flow coefficients. The results show that adding twist to the diffuser vane improves both the compressor stage efficiency and its operating range at a 24° setting angle, regardless of the twist angle. The highest efficiency occurs at the design flow coefficient for all twist angles considered. However, the SPR coefficient increased for twist angles of 9° and 11° up to the 24° setting angle, and decreased at setting angles of 28° and 32°. Based on the selected impeller-diffuser configuration, the optimal twist angle for maximum performance was found to be 9° at a 24° setting angle.

Keywords

Main Subjects

Turbomachinary

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