scholarly journals The development and verification of the Perez diffuse radiation model

1988 ◽  
Author(s):  
R Perez ◽  
R Stewart ◽  
R Seals ◽  
T Guertin
Keyword(s):  
Diffuse Radiation ◽  
Radiation Model

Corrections to anisotropic diffuse radiation model

Solar Energy ◽  
2019 ◽  
Vol 193 ◽  
pp. 523-528 ◽  
Author(s):  
J. Appelbaum ◽  
Y. Massalha ◽  
A. Aronescu
Keyword(s):  
Diffuse Radiation ◽  
Radiation Model

Meteorological Radiation Model (MRM v6.1): Improvements in diffuse radiation estimates and a new approach for implementation of cloud products

2017 ◽  
Vol 74 ◽  
pp. 616-637 ◽  
Author(s):  
H.D. Kambezidis ◽  
B.E. Psiloglou ◽  
D. Karagiannis ◽  
U.C. Dumka ◽  
D.G. Kaskaoutis
Keyword(s):  
Diffuse Radiation ◽  
Radiation Model ◽  
New Approach

scholarly journals Efficient modeling of sun/shade canopy radiation dynamics explicitly accounting for scattering

2011 ◽  
Vol 4 (3) ◽  
pp. 1793-1808
Author(s):  
P. Bodin ◽  
O. Franklin
Keyword(s):  
Large Scale ◽  
Gross Primary Production ◽  
Global Radiation ◽  
Diffuse Radiation ◽  
Computationally Efficient ◽  
Radiation Scattering ◽  
Radiation Model ◽  
3 Dimensional ◽  
Plant Photosynthesis ◽  
Vegetation Models

Abstract. The separation of global radiation (Rg) into its direct (Rb) and diffuse constituents (Rd) is important when modeling plant photosynthesis because a high Rd:Rg ratio has been shown to enhance Gross Primary Production (GPP). To include this effect in vegetation models, the plant canopy must be separated into sunlit and shaded leaves, for example using an explicit 3-dimensional ray tracing model. However, because such models are often too intractable and computationally expensive for theoretical or large scale studies simpler sun-shade approaches are often preferred. A widely used and computationally efficient sun-shade model is a model originally developed by Goudriaan (1977) (GOU), which however does not explicitly account for radiation scattering. Here we present a new model based on the GOU model, but which in contrast explicitly simulates radiation scattering by sunlit leaves and the absorption of this radiation by the canopy layers above and below (2-stream approach). Compared to the GOU model our model predicts significantly different profiles of scattered radiation that are in better agreement with measured profiles of downwelling diffuse radiation. With respect to these data our model's performance is equal to a more complex and much slower iterative radiation model while maintaining the simplicity and computational efficiency of the GOU model.

scholarly journals The M-1 Radiation Model: Evaluation for Predicting Thermal Radiation From Fires

2012 ◽  
Author(s):  
Alexander L. Brown ◽  
Flint Pierce
Keyword(s):  
Thermal Radiation ◽  
Transport Model ◽  
Hyperbolic Equations ◽  
Radiation Transport ◽  
Diffuse Radiation ◽  
Radiative Energy ◽  
Discrete Ordinates ◽  
Radiation Model ◽  
Radiation Transport Model ◽  
The Cost

The M-1 radiation model is a thermal radiation transport model that is derived from a maximum entropy approximation to the radiative transport equation. It involves the solution of four hyperbolic equations for conservation of radiative energy. The M-1 model has similarities to the classical diffusion approximations (like P-1), but is able to better predict directed flux. Consequently, shadowing and long-range transport can be well resolved for a fraction of the cost of methods with exponentially increasing accuracy costs like the method of discrete ordinates and Monte Carlo ray-tracing. The M-1 method is mostly used historically in astronomical radiation transport, but has recently been shown to work for combustion applications of smaller scale. Past work has shown it to give good comparisons to fire problems with length scales of interest. Because of the potential for the model to predict radiation transport more cost-effectively, it is being examined for implementation as an option in our fire codes. We present the theory behind the model. The Eddington factor is used to partition directed and diffuse radiation. It is normally modeled since it is derived from a transcendental functional relationship. We analyze Eddington factor models presented in previous work, and present a new model that we show to be superior in most ways to all the previously presented models. Some 1-dimensional calculations are also shown that illustrate the potential accuracy and challenges with implementing the M-1 model. Such challenges include the specification of boundary conditions and the development of robust solver methods.

scholarly journals On the Optimal Tilt Angle and Orientation of an On-Site Solar Photovoltaic Energy Generation System for Sabah’s Rural Electrification

2021 ◽  
Vol 13 (10) ◽  
pp. 5730
Author(s):  
Maryon Eliza Matius ◽  
Mohd Azlan Ismail ◽  
Yan Yan Farm ◽  
Adriana Erica Amaludin ◽  
Mohd Adzrie Radzali ◽  
...  
Keyword(s):  
Tilt Angle ◽  
Diffuse Radiation ◽  
Rural Electrification ◽  
Solar Photovoltaic ◽  
Solar Pv ◽  
Generation System ◽  
Output Data ◽  
Radiation Model ◽  
Pv Generation ◽  
Ongoing Project

An ongoing project to implement a mini standalone solar photovoltaic (PV) generation system of 2.5 kWp capacity at the eco-tourism centre of Liogu Ku Silou-Silou (EPLISSI), Sabah, was initiated in 2019. Since the solar panel support (ground mounting) used in this project will be erected separately, the main goals of this study are to estimate the optimum tilt angle, βopt, and orientation for the solar PV modules. To achieve these goals, the Liu and Jordan isotropic diffuse radiation model was used (1960). Another three isotropic diffuse sky radiation models (Koronakis model, Badescu model, and Tian model) were applied to estimate the optimum tilt angle with the orientation kept facing due south. For verification purposes, the PV power output data obtained from an online PV simulator known as Global Solar Atlas or GSA 2.3 was used and compared to the results of the four isotropic models. The results suggest that the Tian model is more suitable for approximating insolation, as it was proven to have the lowest difference among all models and is in close agreement with the result of the optimum tilt angle provided by GSA 2.3. However, the outcomes demonstrated from the isotropic models propose an error up to 30% (in the range of 31% to 32%) as compared to GSA 2.3.

A new anisotropic diffuse radiation model

2015 ◽  
Vol 95 ◽  
pp. 304-313 ◽  
Author(s):  
Wanxiang Yao ◽  
Zhengrong Li ◽  
Qun Zhao ◽  
Yuan Lu ◽  
Ruiyang Lu
Keyword(s):  
Diffuse Radiation ◽  
Radiation Model

A simplified model exploration research of new anisotropic diffuse radiation model

2016 ◽  
Vol 126 ◽  
pp. 724-735 ◽  
Author(s):  
Wanxiang Yao ◽  
Zhengrong Li ◽  
Xiao Wang ◽  
Qun Zhao ◽  
Zhigang Zhang ◽  
...  
Keyword(s):  
Diffuse Radiation ◽  
Simplified Model ◽  
Radiation Model
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