Improvement of cavitation mass transfer modeling based on local flow properties
Artikel i vetenskaplig tidskrift, 2017

This paper presents and studies the effect of two modifications to improve cavitation mass transfer source term modeling for transport equation based models by considering local flow properties. The first improvement is by creating an analogy between the phase change time scale and turbulence time scale, and have the model to automatically adjust mass transfer rate based on the flow. This will alleviate the manual calibration of model parameter that is often necessary in presently used models. The second modification introduces an influence of shear stress on the liquid rupture in flows relevant for hydromachinery. This relates to that the pressure threshold, which represents the criteria of when phase change occurs, is normally taken as the value relevant for a fluid at rest, but is in reality affected by the flow conditions. To demonstrate the effect of the model modifications, the three-dimensional, fully turbulent, cavitating flow around the Delft Twist11 foil is simulated. The suggested modifications are implemented in and evaluated using the Sauer mass transfer model, with simulations performed with an incompressible implicit LES flow model. The pressure distribution across different sections of the foil, lift force, and cavitation behavior, such as generation, separation, and collapse processes, are studied and compared with the experimental data. The comparison shows the capability of the presented model to improve the prediction of the complex physics of the cavitation around the Twist11 foil, compared with using only the original Sauer mass transfer model.

Turbulent

Mass transfer model

Simulation

LES

Cavitation

Författare

Abolfazl Asnaghi

Chalmers, Sjöfart och marin teknik, Marin teknik

Andreas Feymark

Chalmers, Sjöfart och marin teknik, Marin teknik

Rickard Bensow

Chalmers, Sjöfart och marin teknik, Marin teknik

International Journal of Multiphase Flow

0301-9322 (ISSN)

Vol. 93 142-157

Styrkeområden

Transport

Energi

Fundament

Grundläggande vetenskaper

Infrastruktur

C3SE (Chalmers Centre for Computational Science and Engineering)

Ämneskategorier

Strömningsmekanik och akustik

DOI

10.1016/j.ijmultiphaseflow.2017.04.005