Journal Published Online: 24 April 2018
Volume 46, Issue 4

Evaluation for VOF Simulation of Flow Field in Asphalt Foaming Chamber Based on Volume Fraction

CODEN: JTEVAB

Abstract

Asphalt with high viscosity, air, and water constitutes multi-phase turbulent flow accompanied by complex dynamic phenomena such as heat transfer and phase transition in the foaming chamber during the asphalt foaming process. The foaming process is difficult to fully describe by mathematical model. In order to establish the correspondence between the approximate simulation flow field in the foaming chamber and the physical experiment, it is necessary to propose a reasonable evaluation method for the flow field simulation in the foaming chamber. Approximate numerical expression of asphalt foaming process is established by the volume of fluid (VOF) multiphase flow calculation method combined with self-defined phase and mass transfer functions. Based on the principle of asphalt foaming, effective foaming area is defined as the area where temperature is ≥100°C, volume fraction of asphalt is ≥0.5, and volume fraction of water vapor is between 0.1 and 0.4. The ratio of the effective foaming area to the total flow field is taken as the evaluation index. The proportion of effective foaming area obtained by asphalt foaming numerical simulation is compared with the expansion rate and half-life obtained by asphalt foaming experiments with three foaming chambers of different sizes. The comparison shows that ratio of effective foaming area has the same tendency as expansion rate and half-life. And the simulation evaluation index is verified. Suggestions are put forward on the structure design of asphalt foaming chamber based on the distribution of effective foaming area. It shows that this method achieves rapid theoretical evaluation of foaming chamber structure and could be used for the optimal design of foaming chamber.

Author Information

Liu, Fu-Min
School of Mechanical Engineering, Tongji University, Shanghai, People’s Republic of China
Wang, An-Lin
School of Mechanical Engineering, Tongji University, Shanghai, People’s Republic of China
Fu, Zhen-Sheng
School of Mechanical Engineering, Tongji University, Shanghai, People’s Republic of China
Pages: 8
Price: $25.00
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Stock #: JTE20170484
ISSN: 0090-3973
DOI: 10.1520/JTE20170484