Mohan Xu , Huaiyu Cheng , Bin Ji , Xiaoxing Peng , Cheng Liu
{"title":"Numerical study on the scale effect of tip vortex cavitation with special emphasis on non-condensable nuclei","authors":"Mohan Xu , Huaiyu Cheng , Bin Ji , Xiaoxing Peng , Cheng Liu","doi":"10.1016/j.ijmultiphaseflow.2025.105346","DOIUrl":null,"url":null,"abstract":"<div><div>Tip vortex cavitation (TVC) around a family of elliptic NACA66<sub>2</sub>–415 hydrofoils with different scales (<em>λ</em>=0.5, 0.75, 1) under the same cavitation number is simulated to study its scale effect. A satisfying agreement is obtained between the numerical and experimental results. Our results suggest that although TVC varies with scales without considering the influence of non-condensable nuclei, that difference is much more significant when nuclei effect is considered in the simulations. Moreover, it indicates that nuclei influence is more significant for a larger scale. It strongly proves the important role of nuclei in TVC scale effect. By comparing the pressure gradients in various directions, it is found that the pressure gradient in the radial direction leads to the enrichment of nuclei in the tip vortex core. With the increase of scale, the radial pressure gradient increases, which further causes the increase of nuclei concentration. In addition, a practical method for predicting nuclei concentration in the tip vortex core is proposed. The theoretical derivation indicates the proportionality between the dimensionless nuclei concentration in the tip vortex core and the dimensionless circulation, which is validated by the numerical results. A fitting equation between dimensionless nuclei concentration and tip vortex circulation is then provided, by which the nuclei concentration can be forecast without the time-consuming simulation of nuclei movement.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"192 ","pages":"Article 105346"},"PeriodicalIF":3.8000,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Multiphase Flow","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0301932225002241","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MECHANICS","Score":null,"Total":0}
引用次数: 0
Abstract
Tip vortex cavitation (TVC) around a family of elliptic NACA662–415 hydrofoils with different scales (λ=0.5, 0.75, 1) under the same cavitation number is simulated to study its scale effect. A satisfying agreement is obtained between the numerical and experimental results. Our results suggest that although TVC varies with scales without considering the influence of non-condensable nuclei, that difference is much more significant when nuclei effect is considered in the simulations. Moreover, it indicates that nuclei influence is more significant for a larger scale. It strongly proves the important role of nuclei in TVC scale effect. By comparing the pressure gradients in various directions, it is found that the pressure gradient in the radial direction leads to the enrichment of nuclei in the tip vortex core. With the increase of scale, the radial pressure gradient increases, which further causes the increase of nuclei concentration. In addition, a practical method for predicting nuclei concentration in the tip vortex core is proposed. The theoretical derivation indicates the proportionality between the dimensionless nuclei concentration in the tip vortex core and the dimensionless circulation, which is validated by the numerical results. A fitting equation between dimensionless nuclei concentration and tip vortex circulation is then provided, by which the nuclei concentration can be forecast without the time-consuming simulation of nuclei movement.
期刊介绍:
The International Journal of Multiphase Flow publishes analytical, numerical and experimental articles of lasting interest. The scope of the journal includes all aspects of mass, momentum and energy exchange phenomena among different phases such as occur in disperse flows, gas–liquid and liquid–liquid flows, flows in porous media, boiling, granular flows and others.
The journal publishes full papers, brief communications and conference announcements.