# Letter: Modified normalized Rortex/vortex identification method

## TL;DR

This paper introduces a simplified, improved Rortex/vortex identification method called Omega_R that addresses previous issues and enhances computational efficiency, with demonstrated effectiveness through numerical results.

## Contribution

A modified Omega_R method is proposed that simplifies calculations and resolves the bulging phenomenon in vortex identification.

## Key findings

- Effective in reducing the bulging phenomenon on iso-surfaces
- Simplifies the calculation process by removing the need for coordinate rotations
- Numerical results confirm improved vortex identification accuracy

## Abstract

In this paper, a modified normalized Rortex/vortex identification method named Omega_R is presented to improve the original Omega_R method and cure the bulging phenomenon on the iso-surfaces caused by the original Omega_R method. Detailed mathematical explanations and the relationship with the Q criterion are described. In addition, the new developed formula does not require two original coordinate rotations, and the calculation is greatly simplified. The numerical results are demonstrated to show the effectiveness of the new modified normalized Rortex/vortex identification method.

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Source: https://tomesphere.com/paper/1905.03655