The objective of this PhD research is to extend the understanding and modelling of the low wind effect on large telescopes, specifically using Large Eddy Simulation (LES) to capture the characteristics of time varying flows and the transient behaviour of temperature. The low wind effect, which causes image degradation in telescopes due to temperature-induced refractive index variations, has significant implications for astronomical observations.

Previous studies have utilized RANS and URANS models, primarily in 2D, but these approaches have limitations in capturing the complex, unsteady flow phenomena accurately.

This research aims to leverage the capabilities of LES and 3D CFD simulations to provide a more comprehensive understanding and potential solutions for mitigating the low wind effect. The low wind effect was initially observed in the Very Large Telescope in the Atacama Desert, Chile. It occurs when warmer ambient wind interacts with the cooler telescope structure, leading to temperature gradients and subsequent refractive index variations. These variations cause phase shifts in the light wavefront, resulting in image artifacts known as speckles. Accurate modelling of this phenomenon is critical for improving image quality and reliability.

ESO Supervisor: Martin Brinkmann

Collaboration with TUM (Supervisor: Pr. Manhart)