Estimating the effect of wind loading on extremely large telescope performance using computational fluid dynamics

Konstantinos Vogiatzis; Anna Segurson; George Z. Angeli

doi:10.1117/12.551477

16 September 2004 Estimating the effect of wind loading on extremely large telescope performance using computational fluid dynamics

Konstantinos Vogiatzis, Anna Segurson, George Z. Angeli

Author Affiliations +

Proceedings Volume 5497, Modeling and Systems Engineering for Astronomy; (2004) https://doi.org/10.1117/12.551477
Event: SPIE Astronomical Telescopes + Instrumentation, 2004, Glasgow, United Kingdom

Abstract

Wind loading is one of the critical parameters influencing the performance of large telescopes, with potentially more dramatic consequences for proposed future giant telescopes. This study describes a strategy for modeling the effects of wind loading on extremely large telescopes such as the Thirty Meter Telescope (TMT). The optical performance of the telescope is estimated by an integrated model, which incorporates the telescope structure, optics, and control. To model the dynamic force variation on the telescope, a Finite Element Analysis (FEA) model of the telescope is created along with an unsteady Computational Fluid Dynamics (CFD) model of the airflow around the enclosure-telescope configuration, which should have a suitable level of geometric fidelity. Numerical simulations using the CFD model are performed for a chosen wind speed and telescope orientation (azimuth, zenith), through which the dynamic force pattern on the primary and secondary mirrors as well as on the secondary support structure can be determined. Finally the force pattern is applied to the FEA model. This can be achieved either by applying temporally and spatially filtered white noise forces with random distribution deducted from the CFD analysis, or by considering the dynamic force pattern itself from the unsteady CFD calculations. Since the FEA and CFD models usually have different resolution requirements and consequently different, non-uniform spatial sampling grids, a key part of the interface is the conversions necessary to transfer the forces from CFD surface cells to structural nodes.

Citation Download Citation

Konstantinos Vogiatzis, Anna Segurson, and George Z. Angeli "Estimating the effect of wind loading on extremely large telescope performance using computational fluid dynamics", Proc. SPIE 5497, Modeling and Systems Engineering for Astronomy, (16 September 2004); https://doi.org/10.1117/12.551477

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available