scholarly journals Design and Characterization of a 7.2 KW Solar Simulator

Author(s):  
Antoine Boubault ◽  
Julius Yellowhair ◽  
Clifford K. Ho

A 7.2 kW radiative solar simulator was designed in order to perform accelerated testing on absorber materials for concentrating solar power (CSP) technologies. Computer-aided design (CAD) software integrating a ray-tracing tool was used to select appropriate components and optimize their positioning in order to achieve the desired concentration. The simulator comprises four identical units, each made out of an ellipsoidal reflector, a metal halide lamp and an adjustable holding system. A single unit was characterized and shows an experimental average irradiance of 257 kW m−2 on a 25.4 mm (1 inch) diameter spot. Shape, spot size and average irradiance are in good agreement with the model predictions. The innovative four-lamp solar simulator potentially demonstrates peak irradiance of 1140 kW m−2 and average irradiance of 878 kW m−2 over a 25.4 mm diameter spot. The costs per radiative and electric watt are calculated at $2.31 W−1 and $1.99 W−1, respectively.

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Antoine Boubault ◽  
Julius Yellowhair ◽  
Clifford K. Ho

A 7.2 kW (electric input) solar simulator was designed in order to perform accelerated testing on absorber materials for concentrating solar power (CSP) technologies. computer-aided design (cad) software integrating a ray-tracing tool was used to select appropriate components and optimize their positioning in order to achieve the desired concentration. The simulator comprises four identical units, each made out of an ellipsoidal reflector, a metal halide lamp, and an adjustable holding system. A single unit was characterized and shows an experimental average irradiance of 257 kW m−2 on a 25.4 mm (1 in) diameter spot. Shape, spot size, and average irradiance are in good agreement with the model predictions, provided the emitting arc element model is realistic. The innovative four-lamp solar simulator potentially demonstrates peak irradiance of 1140 kW m−2 and average irradiance of 878 kW m−2 over a 25.4 mm diameter area. The electric-to-radiative efficiency is about 0.86. The costs per radiative and electric watt are calculated at $2.31 W−1 and $1.99 W−1, respectively. An upgraded installation including a sturdier structure, computer-controlled lamps, a more reliable lamp holding system, and safety equipment yields a cost per electric watt of about $3.60 W−1 excluding labor costs.


2015 ◽  
Vol 645-646 ◽  
pp. 70-74 ◽  
Author(s):  
Min Zhong ◽  
Yu Hang Zhao ◽  
Shou Mian Chen ◽  
Ming Li ◽  
Shao Hai Zeng ◽  
...  

An embedded SiGe layer was applied in the source/drain areas (S/D) of a field-effect transistor to boost the performance in the p channels. Raised SiGe S/D plays a critical role in strain engineering. In this study, the relationship between the SiGe overfilling and the enhancement of channel stress was investigated. Systematic technology computer aided design (TCAD) simulations of the SiGe overfill height in a 40 nm PMOS were performed. The simulation results indicate that a moderate SiGe overfilling induces the highest stress in the channel. Corresponding epitaxial growth experiments were done and the obtained experimental data was in good agreement with the simulation results. The effect of the SiGe overfilling is briefly discussed. The results and conclusions presented within this paper might serve as useful references for the optimization of the embedded SiGe stressor for 40 nm logic technology node and beyond.


2016 ◽  
Vol 87 (6) ◽  
pp. 657-668 ◽  
Author(s):  
Keartisak Sriprateep ◽  
Erik LJ Bohez

A method is presented for modeling the tensile behavior of multifilament twisted yarns. A filament assembly model and a computer-aided design/computer-aided engineering (CAD/CAE) approach are proposed for the tensile analysis. The geometry of the twisted yarn and the nonlinear filament properties were considered. The finite element method (FEM) and large deformation effects were applied for computation of the stress–extension curves. Ideal yarn structures of five layers with different twist angles were simulated to predict the tensile behavior of each filament and each layer. The stress acting on the filaments after yarn extension could be directly analyzed by the FEM. The stress distribution in the filaments showed that the highest stress regions were located at the filament in the center of the yarn and decreased slightly to the yarn surface. The stress–extensions of the filaments were converted to yarn tensile behavior that is shown in terms of the maximum and average stress–extension curves. The results of this prediction model were compared with the stress–strain curves of high-tenacity rayon yarn and the energy method. The maximum stress–extension curves showed very good agreement with experimental results and are more accurate than those obtained by previous methods.


Author(s):  
Rohit Bhat ◽  
Akshay Deshpande ◽  
Rahul Rai ◽  
Ehsan Tarkesh Esfahani

The aim of this paper is to explore a new multimodal Computer Aided Design (CAD) platform based on brain-computer interfaces and touch based systems. The paper describes experiments and algorithms for manipulating geometrical objects in CAD systems using touch-based gestures and movement imagery detected though brain waves. Gestures associated with touch based systems are subjected to ambiguity since they are two dimensional in nature. Brain signals are considered here as the main source to resolve these ambiguities. The brainwaves are recorded in terms of electroencephalogram (EEG) signals. Users wear a neuroheadset and try to move and rotate a target object on a touch screen. As they perform these actions, the EEG headset collects brain activity from 14 locations on the scalp. The data is analyzed in the time-frequency domain to detect the desynchronizations of certain frequency bands (3–7Hz, 8–13 Hz, 14–20Hz 21–29Hz and 30–50Hz) in the temporal cortex as an indication of motor imagery.


2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Jinliang Xu ◽  
Cheng Tang ◽  
Yongpan Cheng ◽  
Zijin Li ◽  
Hui Cao ◽  
...  

The design, construction, and characterization of a solar simulator are reported. The solar simulator consists of an optical system, a power source system, an air cooling system, a control system, and a calibration system. Seven xenon short-arc lamps were used, each consuming 10 kW electricity. The lamps were aligned at the reflector ellipsoidal axis. The stochastic Monte Carlo method analyzed the interactions between light rays and reflector surfaces as well as participating media. The seven lamps have a common focal plane. The focal plane diameters can be changed in the range of 60–120 mm with the lamp module traveling the distance in a range of 0–300 mm. The calibration process established a linear relationship between irradiant fluxes and grayscale values. The measures to reduce irradiant flux error and fluctuations were described. The irradiant flux distribution can be changed by varying the power capacities and/or moving the focal plane locations. The peak fluxes are 1.92, 3.16, and 3.91 MW/m2 for 25%, 50%, and 75% of the full power capacity. The peak flux and temperature exceed 4 MW/m2 and 2300 K, respectively, for the full power capacity. A 8 cm thick refractory brick can be melt in 2 min with the melting temperature of about 2300 K when the solar simulator is operating at 70% of the maximum power capacity.


Symmetry ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 306 ◽  
Author(s):  
Francisco Cavas-Martínez ◽  
Daniel Fernández-Pacheco ◽  
Francisco Cañavate ◽  
Jose Velázquez-Blázquez ◽  
Jose Bolarín ◽  
...  

The validation of new methods for the diagnosis of incipient cases of Keratoconus (KC) with mild visual limitation is of great interest in the field of ophthalmology. During the asymmetric progression of the disease, the current diagnostic indexes do not record the geometric decompensation of the corneal curvature nor the variation of the spatial profile that occurs in singular points of the cornea. The purpose of this work is to determine the structural characterization of the asymmetry of the disease by using morpho-geometric parameters in KC eyes with mild visual limitation including using an analysis of a patient-specific virtual model with the aid of computer-aided design (CAD) tools. This comparative study included 80 eyes of patients classified as mild KC according to the degree of visual limitation and a control group of 122 eyes of normal patients. The metric with the highest area under the receiver operating characteristic (ROC) curve was the posterior apex deviation. The most prominent correlation was found between the anterior and posterior deviations of the thinnest point for the mild keratoconic cases. This new custom computational approach provides the clinician with a three-dimensional view of the corneal architecture when the visual loss starts to impair.


1979 ◽  
Vol 23 (1) ◽  
pp. 55-58 ◽  
Author(s):  
James L. Lewis

The Operator Station Design System is resident in NASA's Johnson Space Center Spacecraft Design Division Design Performance Laboratory. It includes stand-alone mini-computer hardware and Panel Layout Automated Interactive Design and Crew Station Assessment of Reach software. The data base consists of the Shuttle Transportation System Orbiter Crew Compartment (in part), the Orbiter payload bay and remote manipulator (in part), and various anthropometric populations. The system is utilized to provide panel layouts, assess reach and vision, determine interference and fit problems early in the design phase, study design applications as a function of anthropometric and mission requirements, and to accomplish conceptual design to support advanced study efforts.


1994 ◽  
Vol 10 (04) ◽  
pp. 217-222
Author(s):  
Kohji Honda ◽  
Noriyuki Tabushi

A VLCC (very large crude oil carrier) has approximately 1000 curved longitudinal beams, many of which have three-dimensional complicated curvatures. Due to the shortage of highly skilled workers and the need to keep costs down, production and structural designers have worked to reduce the number of such beams. In order to meet the requirements of production, the authors' company has attempted several design approaches for the longitudinal beam layout to reduce the number of beams that have complicated curvature. Recently, through the application of a computer-aided design system, which has been improved for shipbuilding based on the Calma's system, a new design method for the longitudinal beam layout has been successfully developed. A significant number of beams with a twisted configuration have been eliminated and replaced with beams of simpler, two-dimensional shapes. This paper shows the transition of these design approaches, and the application of the new design to building a VLCC.


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