Benchmark calculations of bubble dynamics are essential for helping us learn more about complicated fluid mechanics. To make sure that theoretical models and numerical methods in the field of bubble flow dynamics are correct, the current simulation is of importance. Benchmarks help researchers figure out how accurate and reliable their computer methods are by giving them a standard against which to compare them. We checked and validated a benchmark book on bubble dynamics. The proposal paper is titled “ Proposal for quantitative benchmark computations of bubble dynamics “ [1].

• Benchmark Reference [1]: Hysing, Shu-Ren, et al. Proposal for quantitative benchmark computations of bubble dynamics. Technische Universität, Fakultät für Mathematik, 2007.

Figure 1: Simulation of a rising bubble [1]

Simulation Process

The geometry configuration model is given in Fig.2. Primarily, It is modeled by Design Modeler. With only generation of 12800 hexahedra cells, a structured grid is formed. The Volume-of-Fluid multiphase model is utilized. This is where the usage of structured grid becomes more significant. The Unsteady nature of rising of the bubble means Transient solver. Further, the initial bubble is produced by patch technique.

Figure 2: Geometry configuration of bubble flow dynamics CFD Simulation [1]

Post-processing

The paper validation study we did shows that our model is very accurate at predicting how bubbles move, especially when it comes to rising velocity. It can be understood that our model works well with benchmark data given in Figure 5 of the paper, which shows how closely our computer results match up with set standards. The graph displays how the velocity of the bubbles changed over time. The dashed line from our study closely follows the solid line from the benchmark data. This connection is solid during the critical initial acceleration phase, when the speed goes from 0 to about 0.25 m/s very quickly in the first 0.1 seconds.

Figure 3: Rising velocity of benchmark paper and CFD Simulation in Bubble flow dynamics

After the initial speeding up, both our model and the paper data presents a small slowing down, followed by a steadying of the speed. This pattern shows how complex buoyant forces and fluid resistance work together. Notably, our model slightly overestimates the speed in the second half of the simulation, so the steady-state speed stays a little higher than the benchmark. Even though this difference isn’t remarkable, it shows that our model could use some work, especially when it comes to describing how bubbles behave over time. Overall, the excellent match between our computer results and the standard data, especially when it comes to catching the important initial dynamics, proves that our simulation method for studying bubble flow dynamics is accurate and reliable.