# Helicity of convective flows from localized heat source in a rotating layer

## TL;DR

This study combines experiments and simulations to analyze the structure and helicity of cyclonic vortices generated by localized heat sources in rotating fluids, revealing two key mechanisms of helicity generation.

## Contribution

It introduces a detailed analysis of helicity mechanisms in rotating convective flows with localized heating, supported by CFD simulations and experimental data.

## Key findings

- Helicity distribution is significantly influenced by central upward flow and peripheral velocity gradients.
- Two main mechanisms of helicity generation are identified: vortex-upward flow correlation and peripheral velocity gradients.
- The integral helicity in the system is high, indicating strong cyclonic activity.

## Abstract

Experimental and numerical study of the steady-state cyclonic vortex from isolated heat source in a rotating fluid layer is described. The structure of laboratory cyclonic vortex is similar to the typical structure of tropical cyclones from observational data and numerical modelling including secondary flows in the boundary layer. Differential characteristics of the flow were studied by numerical simulation using CFD software FlowVision. Helicity distribution in rotating fluid layer with localized heat source was analysed. Two mechanisms which play role in helicity generation are found. The first one is the strong correlation of cyclonic vortex and intensive upward motion in the central part of the vessel. The second one is due to large gradients of velocity on the periphery. The integral helicity in the considered case is substantial and its relative level is high.