Modeling specular transmission of complex fenestration systems with data-driven BSDFs

Autor: Jan Wienold, Taoning Wang, Eleanor S. Lee, Jacob C. Jonsson, Lars Oliver Grobe, David Geisler-Moroder, Gregory Ward
Rok vydání: 2021
Předmět:
Windows
Environmental Engineering
Computer science
Environmental Science and Management
Acoustics
Geography
Planning and Development
0211 other engineering and technologies
02 engineering and technology
010501 environmental sciences
Bidirectional Scattering Distribution Function
01 natural sciences
Luminance
complex fenestration systems
Complex fenestration systems
Bidirectional scattering distribution function
Architecture
Building
021108 energy
Specular reflection
windows
Goniophotometer
Daylighting
Discomfort glare
0105 earth and related environmental sciences
Civil and Structural Engineering
Parametric statistics
Building & Construction
Bidirectional Scattering distribution function
Building energy efficiency
building energy efficiency
daylighting
Illuminance
Glare (vision)
Building and Construction
discomfort glare
Interpolation
Zdroj: Building and Environment, 196
ISSN: 0360-1323
Popis: A Bidirectional Scattering Distribution Function (BSDF) describes how light from each incident direction is scattered (reflected and transmitted) by a simple or composite surface, such as a window shade. Compact, tabular BSDFs may be derived via interpolation, discretization and/or compression from goniophotometer measurements. These data-driven BSDFs can represent any measurable distribution to the limits of their tabulated resolution, making them more general than parametric or analytical BSDFs, which are restricted to a particular class of materials. However, tabulated BSDFs present a trade-off between higher sampling loads versus lower directional accuracy during simulation. Low-resolution BSDFs (e.g., Klems basis) may be adequate for calculating solar heat gains but fall short when applied to daylight glare predictions. The tensor-tree representation moderates this trade-off using a variable-resolution basis, providing detail where needed at an acceptable cost. Independently, a peak extraction algorithm isolates direct transmission from any tabular BSDF, enabling highresolution beam radiation and glare analysis through transmitting systems with a “vision” component. Our data-driven BSDF methods were validated with a pilot study of a fabric shade installed in an outdoor, full-scale office testbed. Comparisons between measurement and simulation were made for vertical illuminance, specular and near-specular transmission, and daylight glare probability. Models based on high resolution BSDF measurements yielded superior results when accounting for anisotropy compared to isotropic models. Models with higher resolution produced more accurate source luminance data than low-resolution models. Further validation work is needed to better characterize generality of observed trends from this pilot study.
Building and Environment, 196
ISSN:0360-1323
Databáze: OpenAIRE
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