Numerical simulation of steady-state thermal blooming with natural convection

Autor: Jeremiah S. Lane, Justin Cook, Martin Richardson, Benjamin F. Akers
Rok vydání: 2023
Předmět:
Zdroj: Applied Optics. 62:2092
ISSN: 2155-3165
1559-128X
0030-3992
DOI: 10.1364/ao.484224
Popis: This work investigates steady-state thermal blooming of a high-energy laser in the presence of laser-driven convection. While thermal blooming has historically been simulated with prescribed fluid velocities, the model introduced here solves for the fluid dynamics along the propagation path using a Boussinesq approximation to the incompressible Navier–Stokes equations. The resultant temperature fluctuations were coupled to refractive index fluctuations, and the beam propagation was modeled using the paraxial wave equation. Fixed-point methods were used to solve the fluid equations as well as to couple the beam propagation to the steady-state flow. The simulated results are discussed relative to recent experimental thermal blooming results [Opt. Laser Technol. 146, 107568 (2022) OLTCAS0030-399210.1016/j.optlastec.2021.107568], with half-moon irradiance patterns matching for a laser wavelength at moderate absorption. Higher energy lasers were simulated within an atmospheric transmission window, with the laser irradiance exhibiting crescent profiles.
Databáze: OpenAIRE
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