Model combines thermal forces and fluids in rotation to mimic hydrodynamics of cyclones

The internal dynamics and physics of tropical cyclones remains a central question in meteorology, but providing a reliable experimental model for such storms remains elusive. While numerical models have demonstrated large-scale vortices, the physical conditions to produce a vortex with an eye and eyewall in a confined volume is unclear.

Kannan et al. have developed a simulation model for determining hydrodynamic conditions that allow vortices to form and mature into cyclone-like structures in a well-controlled environment. Using large-eddy simulations of rotating convection in a shallow cylindrical domain, the group’s approach mimics the sun’s heating and Earth’s rotation. By varying thermal forcing and rotation rates, they identified a condition for the formation of cyclone-like structures.

“This work provides a conceptual bridge between idealized studies of rotating convection and real geophysical vortices,” said author Veeraraghavan Kannan. “What surprised us was the robustness of the mechanism.

The group found two timescales key to cyclone formation: one for intensification linked to angular momentum organization and eyewall formation, and another for the fluid’s rotational spin-up.

“Even without moisture or latent heat release, the model produced realistic eye and eyewall structures,” Kannan said. “This suggests that fundamental hydrodynamics alone can organize turbulence into a cyclone-like vortex.”

They observed that tropical cyclone-like vortex forms only if the intensification occurs before the saturation. They then derived a simple criterion relating the thermal forces and rotation on the fluid motion to predict cyclone behavior in both lab experiments and numerical models.

They next look to extend the framework to moist convection and examine how latent heat release affects the balance between intensification, saturation, and the vortex structure.

Source: “Large-eddy simulation of tropical cyclone-like vortex in confined-rotating convection,” by Veeraraghavan Kannan, Nedunchezhian Swaminathan, and Peter A. Davidson, Physics of Fluids (2026). The article can be accessed at https://doi.org/10.1063/5.0315185 .