Simulation des Grandes \'Echelles d'un \'ecoulement d'air turbulent pour le refroidissement d'amplificateurs de lasers

TL;DR

This paper presents a Large Eddy Simulation study of turbulent air flow in a wind tunnel setup to understand boundary layer development relevant for cooling high-power laser amplifiers.

Contribution

It demonstrates the application of LES CFD modeling to simulate turbulent boundary layers in a setup mimicking laser amplifier cooling systems.

Findings

Turbulent boundary layers develop from the edges of the plates.

LES simulation accurately captures flow development in the experimental setup.

Validation against experimental conditions confirms the model's effectiveness.

Abstract

The French collaborative Trio4CLF project aims to understand and control the cryogenic cooling of amplifiers for high power (~1 PetaWatt) and high repetition rate (1-10 Hertz) lasers. In such amplifiers, the fluid evacuates the thermal power absorbed by the solid amplifying plates. A precise knowledge of the heat exchange and thus of the turbulent fluid flow in the amplifier is requested to evaluate its impact on the laser beam quality. As a first step, a Large Eddy Simulation is carried out in air without heating to study the development of the turbulent flow. The CFD code used is TrioCFD, a code developed by the CEA. For validation purpose, the simulation is carried out in the experimental setup configuration: a closed-loop wind tunnel called TRANSAT. Two horizontal plates, separated by 0.05 m, are put in the airflow to represent the amplifier plates. Turbulent boundary layers develop from the plates edges. Numerically, the entrance flow is a homogeneous planar flow with a constant velocity at 10 m/s. The results of this Large Eddy Simulation are presented in this paper as a study of the development of the turbulent boundary layers created by the plates.