摘要

This paper concerns the modeling of boiling bubbly flow with a multisize approach. In industrial applications as well as in natural bubbly flows, bubbles generally exhibit a full spectrum of different sizes and shapes that influences their behavior. Two major methods have emerged in the literature to take into account the effects of these distributions. The first one is the moments method and the second one is the MUSIG (for MUlti SIze Group) method. In the moments method, a given mathematical law describes the bubble size distribution. In the MUSIG method, a discrete bubble size distribution is assumed and used in the numerical solution of the problem. In this paper a moments method is developed and applied to boiling bubbly flows in a vertical pipe. The results are compared to experimental data. The axial changes of the local void fraction and liquid temperature radial profiles are well reproduced by the model, despite the too-high values of the predicted interfacial area concentration (and consequently the too-low values of the bubble Sauter mean diameter). This discrepancy between a good prediction of the void fraction and an overestimated interfacial area concentration could be due to the nonsphericity of the bubbles.