Master Course for Fluid Simulation Analysis of Multi-phase Flows by Oka-san: 13. Analysis example – Chocolate fountain
Analysis example – Chocolate fountain
The transient start-up of a chocolate fountain is analyzed to demonstrate the VOF (Volume of Fluid) method. Have you ever seen a chocolate fountain? Sometimes they can be seen at parties. Melted chocolate flows over multiple levels into a basin. Fresh fruit (or practically anything) can be dipped into the flowing chocolate or into the basin.
Material properties for chocolate:
Density
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1,000 kg/m3
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Viscosity
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0.10 Pa・s (The viscosity of melted chocolate is greater. However, in this example, cream is mixed with the chocolate to create a smooth flow,
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Surface tension
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0.07 N/m
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Contact angle
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60°
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Figure 1 shows an animation of a chocolate fountain from the beginning, when the chocolate starts to flow, until 1.2 seconds. Icicle-shaped chocolate columns are well simulated. The animation speed is 5 times slower than real time. Simulating formation of the liquid films of chocolate will require substantial calculation time and is not shown here.
Figure 1: Chocolate fountain
About the Author
Katsutaka Okamori | Born in October 1966, Tokyo, Japan
He attained a master’s degree in Applied Chemistry from Keio University. As a certified Grade 1 engineer (JSME certification) specializing in multi-phase flow evaluation, Okamori contributed to CFD program development while at Nippon Sanso (currently TAIYO NIPPON SANSO CORPORATION). He also has experience providing technical sales support for commercial software, and technical CFD support for product design and development groups at major manufacturing firms. Okamori now works as a sales engineer at Software Cradle.