Cavitation and structural analysis on a flanged diffuser applied to hydrokinetic turbines

Materia

article

Yves Alexandrino Bandeira¹  Leonardo Dantas Rodrigues¹  Jerson Rogério Pinheiro Vaz¹  Erb Ferreira Lins² 

[1] Universidade Federal do Pará;Universidade Federal Rural do Pernambuco

关键词: Cavitation;    Flanged Diffuser;    Rayleigh-Plesset model;    Computational Fluid Dynamics;    Fluid-Structural interaction;   

DOI  :  10.1590/1517-7076-RMAT-2022-0265

学科分类：工程和技术（综合）

来源: Universidade Federal do Rio de Janeiro * Coordenacao dos Programas de Pos-Graduacao de Engenharia

【 摘 要 】

Flanged diffuser can improve hydrokinetic turbine efficiency. However, in the current literature it is still not clear if the flange allows the possibility of cavitation on its structure, and whether it can support high pressure variation. This work presents a Computational Fluid Dynamics (CFD) study on the effect of cavitation on a flanged diffuser. The water flow through the diffuser was evaluated using a Reynolds Averaged Navier Stokes approach coupled to the Rayleigh-Plesset model to estimate the vapor production rate. The methodology was applied to a flanged diffuser and results were compared with experimental data from the literature. The minimal depth to avoid cavitation on the flanged diffuser was found. The pressure field obtained on CFD was applied as loading in structural analysis using Finite Element Method. The numerical model presented good agreement with experimental data available in the literature. The results showed that cavitation occurs more intensely at a depth of 1.0 m for the model. This intensity gradually decreases as the depth increases. Cavitation can be present in flanged diffusers, especially in the region inside the shroud, where it can directly impact the flow through the rotor. A good safety factor was obtained in the structural analysis.

【 授权许可】

CC BY