MRI and Georgia Tech, a top 10 public research university located in Atlanta, GA have been steadily collaborating on research involving two district aspects of BoldVu® displays: the internal cooling system of outdoor digital displays, as well an internet-of-things (IoT)-based low-cost sensor network deployed in outdoor digital displays that can be used to collect the data necessary to study both Urban Heat Island (UHI) and air pollution.
Several publications have resulted from this collaboration, in the form of conference proceedings and journal papers. All this in an effort to establish research-based evidence for claims of the performance and utility of BoldVu® displays in applicable markets.
Publication:
Thermal Modeling of Outdoor Digital Displays Under Different Brightness Outputs
Citation:
Kim, J. Michael Brown, K. O’Connor, M. Diaz and Y. Joshi, “Thermal Modeling of Outdoor Digital Displays Under Different Brightness Outputs,” in IEEE Transactions on Components, Packaging and Manufacturing Technology, vol. 10, no. 6, pp. 949-955, June 2020, doi: 10.1109/TCPMT.2020.2993521.
Abstract:
The thermal design process for 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 can be impractical due to the high cost of prototyping cycles, time constraints, and inevitable iterations involved. In such cases, thorough CFD/HT models developed early in the design process are valuable for driving the product design. Based on this idea, the study examines thermal performance of 55” outdoor digital displays using CFD/HT tools and a prediction under hazardous outdoor condition is made for two different brightness outputs. The prediction is extrapolated and validated through the outdoor testing and simulation comparisons. It is shown that CFD/HT software can be used as a means of making conservative design choices.
Publication:
Packaging Environmental Sensors for Monitoring Urban-Microclimates
Citation:
Dey, J. M. Brown, and Y. Joshi, “Packaging Environmental Sensors for Monitoring Urban-Microclimates,” ASME Journal of Engineering for Sustainable Buildings and Cities, vol. 1, no. 3, 2020, doi: 10.1115/1.4047422.
Abstract:
An internet-of-things (IoT)-based low-cost sensor network can be used to collect the data necessary to study both Urban Heat Island (UHI) and air pollution. There are several key challenges associated with an IoT-based solution to environmental data monitoring, including packaging and deployment. This study explores these challenges by looking at effects the packaging has on the deployed environmental sensors. Several packaging designs are numerically studied using a computation fluid dynamics (CFD) model. Two sensor designs are chosen using results obtained from CFD modeling and then experimentally deployed. The findings conclude that the IoT sensors chosen for this study are not significantly affected by flow velocities or require advanced packaging designs when paired with street-side outdoor digital displays.
Publication:
Thermal Management of Outdoor Digital Displays – A Review
Citation:
Y. Joshi and J. M. Brown, “Thermal Management of Outdoor Digital Displays – A Review,” 2019 18th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm), Las Vegas, NV, USA, 2019, pp. 772-779, doi: 10.1109/ITHERM.2019.8757287.
Abstract:
Outdoor digital displays are increasingly being used for information dissemination, interactive content location, and advertising in urban locations. While the existing thermal management approaches for indoor digital displays are well understood and generally sufficient due to their lower power dissipation, outdoor liquid crystal displays (LCDs) are subject to many additional constraints, such as harsher and changing ambient environment, solar insolation, and larger internal heat generation in the current state-of-the-art light emitting diodes (LEDs) and other associated electronics. Demands for larger and brighter displays continue to provide significant additional challenges to their thermal design. Here we review the current and emerging thermal management challenges, and current solutions for outdoor digital displays. We review the state-of-the-art of the multi-scale nature of the packaging of the digital displays, from the light sources to the display cabinet. The unique thermal management challenges for outdoor displays are next outlined. We review current thermal management methods for outdoor displays. We conclude by describing emerging applications of outdoor digital displays, and identify associated thermal challenges.
Publication:
Vandal Glass Heat Distribution and the Effect of Glass Gap Adjustments in Outdoor Digital Display Components
Citation:
Kim, J., Michael Brown, J., Joshi, Y., O’connor, K., Diaz, M., Zhang, Z., and Yang, P. (May 4, 2020). “Vandal Glass Heat Distribution and the Effect of Glass Gap Adjustments in Outdoor Digital Display Components.” ASME. J. Electron. Packag. September 2020; 142(3): 031001.
Abstract:
The use of computational fluid dynamics/heat transfer (CFD/HT) software has become common in exploring the thermal and hydrodynamic behavior of many electronic products. Well-designed CFD/HT models are very valuable for driving the product design, but accurate models can be difficult to develop in some cases for a practical use. In CFD/HT modeling of outdoor digital displays, both the surrounding ambient temperature and solar irradiance are the major contributors to temperature rise, but most software packages are limited in simulating solar irradiance through semitransparent materials and multiple surfaces. In this study, a methodology to replace the solar irradiance with a power that should be imposed on the sun-exposed exterior glass (vandal glass) is described. As outdoor digital displays face harsher thermal challenges compared to the displays that are deployed indoors, it is necessary to come up with a display design that can best benefit from the cooling effect. There are numerous parameters that can be adjusted to optimize the display in terms of its thermal performance but in particular, 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.
Publication:
Packaging Environmental Sensors for an Internet-of-Things Solution for Urban-Microclimate Studies
Citation:
Dey, Y. Joshi, and J. M. Brown, “Packaging Environmental Sensors for an Internet-of-Things Solution for Urban-Microclimate Studies,” in ASME 2019 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems, Anaheim, CA, USA, 2019 2019: American Society of Mechanical Engineers, 2019, p. 10, doi: 10.1115/ipack2019-6515.
Abstract:
Cities are experiencing a number of negative effects caused by increasing urbanization. For decades, the effects of pollution have been recognized and studied and steps have been taken attempting to control this problem. Many urban environments are also experiencing the effect of the Urban Heat Island (UHI). UHIs are metropolitan areas that have measurably warmer average air temperatures during several periods during the year, than their surrounding rural areas. There is a great interest in studying UHI and pollution and its effects on the environment as well as urban residents. However, in order to study these phenomena, we need more information than we currently have. Thus, an IoT based low cost sensor network can be used to collect the data necessary to study UHI and pollution. There are several key challenges associated with an IoT based solution to environmental data monitoring. This study explores these challenges by looking at what effect the packaging has on the deployed environmental sensors, and how and where to deploy sensor modules. Sensor data collected over a few months’ timeframe are analyzed and presented.