# Lagrangian statistics of pressure fluctuation events in homogeneous isotropic turbulence

## TL;DR

This study analyzes pressure fluctuation events in homogeneous isotropic turbulence using DNS data, providing statistical insights into low-pressure events relevant for cavitation modeling and their connection to flow structures.

## Contribution

It introduces a detailed statistical analysis of low-pressure fluctuation events in turbulence, linking them to flow structures and pressure distributions, with implications for cavitation prediction.

## Key findings

- Average frequencies of low-pressure events quantified
- Distribution of event durations characterized
- Connection established between pressure events and flow structures

## Abstract

Homogeneous and isotropic turbulent fields obtained from two DNS databases (with $\mbox{Re}_\lambda$ equal to 150 and 418) were seeded with point particles that moved with the local fluid velocity to obtain Lagrangian pressure histories. Motivated by cavitation inception modeling, the statistics of events in which such particles undergo low-pressure fluctuations were computed, parameterized by the amplitude of the fluctuations and by their duration. The main results are the average frequencies of these events and the probabilistic distribution of their duration, which are of predictive value. A connection is also established between these average frequencies and the pressure probability density function, thus justifying experimental methods proposed in the literature. Further analyses of the data show that the occurrence of very-low-pressure events is highly intermittent and is associated with worm-like vortical structures of length comparable to the integral scale of the flow.