SUBJECT: M.S. Thesis Presentation
BY: Jeho Kim
TIME: Thursday, October 17, 2019, 3:00 p.m.
PLACE: Love Building, 210
TITLE: Thermal Modeling of Air Cooled Outdoor Digital Displays
COMMITTEE: Dr. Yogendra Joshi, Chair (ME)
Dr. Zhuomin Zhang (ME)
Dr. Mostafa Ghiaasiaan (ME)


The thermal design process for many electronic products often minimizes the use of computational fluid dynamics and heat transfer (CFD/HT) software in favor of quick prototyping and testing to determine the thermal characteristics of the product. For large-scale products with many thermal challenges, such a strategy may be impractical. In such cases, thoroughly developed simulation models are very valuable in driving the product design. Based on this idea, a methodology in designing a reliable CFD/HT model for outdoor digital displays is described in this study. Both the surrounding ambient temperature and solar irradiance are the major contributors to a temperature rise in such displays, but most CFD/HT software packages are limited in simulating solar irradiance through semi-transparent materials and multiple surfaces. Therefore, the contribution from solar irradiance must be treated with care when creating CFD/HT models especially when an optimum number of mesh elements is used to minimize the necessary processing power and solution computation time. To best accommodate the effect of solar irradiance, in lieu of defining the solar irradiance as a heat flux, a methodology to determine the power that should be imposed on the sun-exposed vandal glasses is described. Simulation results are obtained in the range of environmental temperature/irradiance values that can be experimentally tested. The study examines variation in simulation results between mesh element sizes, meshing techniques and heat loads assigned on the vandal glass assembly. In addition, this study explores the effect of adjusting the gap distance between the vandal glass and the liquid crystal display (LCD) to see how the maximum LCD temperature and fan performance are influenced.