Scientists Confirm Classic Turbulence Theory Using Swarms of Rising Bubbles

Researchers have discovered experimental proof that a fundamental theory of turbulence applies to the chaotic motion generated by rising bubbles in water.

An international team from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Johns Hopkins University, and Duke University has demonstrated that Kolmogorov’s 1941 theory of turbulence—known as K41 scaling—also governs turbulence created by bubbles moving through a fluid. Their findings, published in Physical Review Letters, provide the first direct experimental evidence of Kolmogorov scaling in bubble-driven turbulence.

Figure 1. Turbulent Bubbles.

Turbulence induced by bubbles plays a major role in industry and nature—from sparkling beverages to chemical reactors and ocean wave dynamics. Large groups of bubbles rising through liquid generate swirling flows that mix surrounding water. But for decades, scientists have debated whether this motion truly aligns with classical turbulence theory. Conflicting experiments and simulations left the question unresolved.

“We wanted a definitive answer by observing the turbulence around bubbles in fine detail,” said lead author Dr. Tian Ma, physicist at HZDR’s Institute of Fluid Dynamics. Figure 1 shows Turbulent Bubbles.

3D Tracking Reveals Hidden Turbulence Patterns

The team used advanced 3D simultaneous Lagrangian tracking, enabling real-time measurement of both bubbles and surrounding tracer particles. The experiment took place in an 11.5-cm water column where controlled swarms of bubbles were released from the bottom and recorded at 2,500 frames per second using four high-speed cameras. By varying bubble size and gas flow across four test conditions, the researchers recreated realistic bubbly environments.

Bubbles measuring three to five millimeters were large enough to wobble, producing strong vortex wakes. In two cases, the resulting flow clearly followed Kolmogorov scaling for eddies smaller than the bubbles—marking the first observation of this classic pattern inside a rising bubble swarm.

Decoding the Energy Cascade

“Kolmogorov’s theory elegantly predicts how energy cascades from large turbulent eddies down to smaller scales,” said co-author Dr. Andrew Bragg of Duke University. “Seeing it hold true in bubble-driven turbulence is unexpected and fascinating.”

The team also introduced a new formula to calculate energy dissipation—the rate at which turbulence loses energy—based solely on bubble size and concentration, and it aligned closely with experimental measurements [1]. Interestingly, Kolmogorov scaling was strongest outside the bubbles’ direct wakes, where disturbances were less violent.

Natural Limits—and Future Potential

The researchers emphasize that achieving a perfect Kolmogorov inertial range would require much larger bubbles, which would naturally break apart due to instability. As co-author Dr. Hendrik Hessenkemper explained:“Nature prevents us from reaching perfect Kolmogorov turbulence with bubbles—but under the right conditions, we can get remarkably close.”

The results resolve a long-standing scientific dispute and could improve engineering applications such as chemical mixing, wastewater treatment, and climate modeling. The team plans to explore turbulence involving different bubble shapes, mixtures, or environmental conditions.

“The better we understand turbulence in bubbly flows, the better we can exploit it in real systems,” Ma concluded. “It’s remarkable that a theory from over 80 years ago still proves so powerful— even in a bubbly environment.”

References:

1. https://scitechdaily.com/turbulent-bubbles-confirm-a-century-old-physics-theory/

Cite this article:

Keerthana S (2025), Chaotic Bubbles Validate a 100-Year-Old Physics Prediction, AnaTechMaz, pp.303