Numerical and Experimental Aerodynamic Evaluation of a Solar Vehicle

2017 ◽  
Author(s):  
J. P. De Kock ◽  
R. F. Laubscher ◽  
Sunita Kruger ◽  
N. Janse van Rensburg
Keyword(s):  
Motor Control ◽  
Alternative Energy ◽  
Shape Function ◽  
Aerodynamic Drag ◽  
Function Analysis ◽  
Design Tool ◽  
Weather Data ◽  
Control Data ◽  
Actual Performance ◽  
Straight Line

Solar car racing has created a competitive platform for research into alternative energy solutions and aids development in the green engineering space. The University of Johannesburg’s Solar Racing team developed a vehicle (Ilanga II) to compete in the 2014 South African Solar Car Challenge. This paper describes the numerical optimization of the vehicle’s body shape, utilizing Computational Fluid Dynamics (CFD) and finally compares the simulated results with the actual performance during the race. Motor control data is used to determine the aerodynamic drag coefficient of the vehicle. This work builds on the paper submitted in 2014 [1], which postulated the use of the Hermite cubic function in conjunction with the shape function analysis as a holistic design tool. By analyzing the motor control data it is possible to comment on the effectiveness of the shape function analysis technique. The final optimized design predicted a straight-line ACd 0.078. A yaw angle characterization study of ±25° degrees, in conjunction with historic weather data were used to fully characterize the vehicle with an average drag area coefficient of 0.119. The final comparative results of the simulated data and the race data show that the vehicle’s straight-line (Zero yaw) ACd was 11.2% higher than the simulated results, whereas the average aerodynamic characteristic ACd was 2.43% lower than the simulated results.

scholarly journals A motor imagery during blind action is guided by the same foci of attention as actual performance in a sample comprising females

2014 ◽  
Vol 7 (2) ◽  
pp. 11-16
Author(s):  
Bassem Khalaf
Keyword(s):  
Mental Imagery ◽  
Focus Of Attention ◽  
Direct Role ◽  
Actual Performance ◽  
External Focus ◽  
Deviation Measure ◽  
Straight Line ◽  
Internal Focus ◽  
Perceptual Representations ◽  
Better Than

There is strong evidence that focussing on the goal of an action improves performance relative to focussing on the concrete motor behaviours. The current study tests whether blind action guided by imagery relies on the same foci of attention. Thirty female participants took part in an experiment. In each condition there were 20 trials, they were asked to close their eyes and draw a straight line between two landmarks on a graphics tablet. We instructed them, in three conditions, to focus on (1) mental imagery of the goal landmark (external focus of attention), (2) drawing a straight line with the fingers (internal focus), or (3) without a specific focus of attention (control). We tested to what extent these attention instructions affected drawing performance, in terms of both deviations of the participants’ lines from an ideal straight line, and the time it took to complete the line. The study revealed that the manipulation specifically affected the deviation measure and that an external focus of attention was better than an internal focus and the control condition. These findings reveal that that mental imagery during blind action relies on same processes as actual performance. These data give perceptual representations of a direct role in motor control. They will be related to current theories of action control (constrained action hypothesis, ideomotor theories, and dual task accounts).

scholarly journals Optimization module for filtering and ranking alternative energy replacement systems, in an online ICT design tool for building retrofits

2019 ◽  
Vol 1343 ◽  
pp. 012128
Author(s):  
Peru Elguezabal ◽  
Beñat Arregi ◽  
Alberto Armijo ◽  
Philipp Schuetz ◽  
Damian Gwerder ◽  
...  
Keyword(s):  
Alternative Energy ◽  
Design Tool ◽  
Energy Replacement

A Simplified Model of Desiccant Wheel and Implementation in a Design Tool

2008 ◽  
Author(s):  
Fatemeh Esfandiari Nia ◽  
Dolf van Paassen
Keyword(s):  
Design Tool ◽  
Weather Data ◽  
Physical Parameters ◽  
Transfer Model ◽  
Desiccant Wheel ◽  
New Class ◽  
Sensitivity Studies ◽  
Optimization Routine ◽  
The Given ◽  
Air Streams

A new class of heat and mass transfer model for a desiccant wheel has been presented and implemented in a design tool. Having studied the behavior of the system in different conditions and sensitivity studies, two physical parameters have been chosen to make simplified models or correlations. Using 1500 data of model solutions, two correlations have been made by an optimization routine in Matlab. These equations correlate outlet air conditions of a desiccant wheel to inlet air conditions of air streams and also the wheel and air speeds. The correlations are limited to be used only in the given range of air conditions and wheel speed. However, the range covers the practical situation that usually happens according to the weather data. The behavior of air conditions in Mollier diagram shows that the error for simulation of a typical cooling cycle to calculate supply air conditions is reduced with a factor of almost 3 times smaller. This shows that even in those ranges with low accuracy the correlations are useful. These simplified equations will be used in the design tools as has been presented in details in this paper.

NMR Line Shape Function Analysis in Solids

1987 ◽  
Vol 139 (2) ◽  
pp. K137-K140 ◽  
Author(s):  
B. M. Bolotov ◽  
D. A. Aksenov ◽  
A. I. Polyakov ◽  
S. P. Senshin
Keyword(s):  
Line Shape ◽  
Shape Function ◽  
Function Analysis ◽  
Line Shape Function

scholarly journals Use of discriminant function analysis for forecasting crop yield

MAUSAM ◽  
2022 ◽  
Vol 63 (3) ◽  
pp. 455-458
Author(s):  
RANJANA AGRAWAL ◽  
CHANDRA HAS ◽  
KAUSTAV ADITYA
Keyword(s):  
Discriminant Function ◽  
Discriminant Function Analysis ◽  
Time Series Data ◽  
Function Analysis ◽  
Wheat Yield ◽  
Quadratic Function ◽  
Qualitative Assessment ◽  
Weather Data ◽  
Series Data ◽  
Yield Forecast

The present paper deals with use of discriminant function analysis for developing wheat yield forecast model for Kanpur (India). Discriminant function analysis is a technique of obtaining linear/Quadratic function which discriminates the best among populations and as such, provides qualitative assessment of the probable yield. In this study, quantitative forecasts of yield have been obtained using multiple regression technique taking regressors as weather scores obtained through discriminant function analysis. Time series data of 30 years (1971-2000) have been divided into three categories: congenial, normal and adverse, based on yield distribution. Taking these three groups as three populations, discriminant function analysis has been carried out. Discriminant scores obtained from this have been used as regressors in the modelling. Various strategies of using weekly weather data have been proposed. The models have been used to forecast yield in the subsequent three years 2000-01 to 2002-03 (which were not included in model development). The approach provided reliable yield forecast about two months before harvest.

Ethernet Node Controller for Main Reflector of Radio Telescope

2014 ◽  
Vol 614 ◽  
pp. 480-483
Author(s):  
Ke Mei Sun
Keyword(s):  
Motor Control ◽  
Data Storage ◽  
Control Data ◽  
Control Module ◽  
Interface Circuit ◽  
Display Module ◽  
Control Command ◽  
Main Reflector ◽  
Control Feedback ◽  
And Control

An Ethernet node controller for main reflector of radio astronomical telescope is provided. The controller completes the communication with the main control PC, as well as control and monitoring of actuators through Ethernet and embedded technology. The system is made up of embedded processor and peripheral circuit, Ethernet communication module, power management module, motor control feedback module, data storage and time module, display module, motor control module and interface circuit. The controller uses LPC2368 as the core, DM9161 as the network communication physical layer chip, FM3130 to realize of data storage and real-time clock function. Motor controller can store the control algorithm and control data. And through the Ethernet receive and process control command and control data from the control PC to implement the control of actuators. At the same time, the controller also has regular state detection and alarm function, through the manual control module to achieve positive or reversal control operation of the corresponding channel actuators motor.

Development of Failure Tolerant Multi-Layer Silicon Nitride Ceramics: Review from Macro to Micro Layered Structures

2007 ◽  
Vol 333 ◽  
pp. 117-126
Author(s):  
Jakob Kübler ◽  
Gurdial Blugan ◽  
M. Lugovy ◽  
V. Slyunyayev ◽  
N. Orlovskaya ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Silicon Nitride ◽  
Function Analysis ◽  
Low Cost ◽  
Design Tool ◽  
Apparent Fracture Toughness ◽  
Layer Structures ◽  
Nitride Ceramics ◽  
Recent Developments ◽  
Edge Cracking

Recent developments have shown that producing multi-layer ceramic laminates with alternative layers under compressive and tensile stress can lead to significant improvements in toughness at a low cost. However, in many cases the improvements in fracture toughness is associated with the presence of surface “edge cracks” in the compressive layers or the use of porous interfaces between the layers. At the same time such effects can limit the performance of ceramics when used in harsh environments. This review covers the development of silicon nitride based laminate structures and characterisation of these multi-layer structures. The work presents the results of macro-layered laminates with layers greater than 150 μm thickness. The apparent fracture toughness of different designs is measured and the conditions for failure tolerant effects, including crack deflection, bifurcation and edge cracking, are shown and discussed. The structural and processing limitations of the macro-layered laminates are also presented. The development of a weight function analysis as an effective design tool for developing micro-layered laminates with layers of approximately 50 μm thickness is discussed along with the apparent fracture toughness results from these micro-laminates. The failure tolerant behaviour as well as the ease of producing micro-layered laminates with a toughness of 2-3 times higher than that of silicon nitride is shown.

Wave-Shape Function Analysis

2017 ◽  
Vol 24 (2) ◽  
pp. 451-505 ◽  
Author(s):  
Chen-Yun Lin ◽  
Li Su ◽  
Hau-Tieng Wu
Keyword(s):  
Shape Function ◽  
Function Analysis ◽  
Wave Shape

scholarly journals Livelihood vulnerability and climate change: a comparative analysis of smallholders in the Indo-Gangetic plains

2021 ◽  
Author(s):  
Terese E. Venus ◽  
Stephanie Bilgram ◽  
Johannes Sauer ◽  
Arun Khatri-Chettri
Keyword(s):  
Climate Change ◽  
Adaptive Capacity ◽  
Information And Communication Technologies ◽  
Alternative Energy ◽  
Conservation Agriculture ◽  
Vulnerability Index ◽  
Weather Data ◽  
Gangetic Plains ◽  
Alternative Energy Sources ◽  
Climate Exposure

AbstractIn the Indo-Gangetic Plains, one of India’s most productive agricultural regions, smallholder livelihood vulnerability can inhibit sustainable development. As there are significant differences in economic development, natural resources and agricultural productivity within the region, we estimate the Livelihood Vulnerability Index in two districts (Vaishali, Bihar and Karnal, Haryana) to determine suitable adaptation strategies under diverse conditions. To reflect different aspects of climate exposure, we include both self-reported climate shocks and spatially interpolated weather data. The assessment of 1127 households shows that while both districts have similar exposure and adaptive capacity levels, the sensitivity dimension makes Vaishali more vulnerable to climate change. To reduce sensitivity, decision-makers should focus on improving infrastructure (e.g., permanent housing, latrines, health centers, alternative energy sources). To improve adaptive capacity and reduce climate risk in both regions, policymakers should promote the expansion of extension training for livelihood diversification, information and communication technologies as well as conservation agriculture.

scholarly journals Historical and Future Typical Meteorological Years for 33 locations in Greece: a handy tool for various applications

2021 ◽  
Author(s):  
Basil Psiloglou ◽  
Harry D. Kambezidis ◽  
Konstantinos V. Varotsos ◽  
Dimitris G. Kaskaoutis ◽  
Dimiitris Karagiannis ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Design Tool ◽  
Weather Data ◽  
Climate Simulation ◽  
Total Solar Radiation ◽  
Climatic Data ◽  
Data Set ◽  
Specific Location ◽  
Daily Data

<p>It is generally accepted that a climatic data set of meteorological measurements with true sequences and real interdependencies between meteorological variables is needed for a representative climate simulation. In the late 1970s the Typical Meteorological Year (TMY) concept was introduced in USA as a design tool for approximating expected climate conditions at specific locations, at a time when computers were much slower and had less memory than today. A TMY is a collation of selected weather data for a specific location, listing usually hourly values of meteorological and solar radiation elements for one-year period. The values are generated from a data bank much longer than a year in duration, at least 10 years. It is specially selected so that it presents the range of weather phenomena for the location in question, while still giving annual averages that are consistent with the long-term averages for the specific location. Each TMY data file consists of 12 months chosen as most “typical“ among the years present in the long-term data set. Although TMYs do not provide information about extreme events and do not necessarily represent actual conditions at any given time, they still reflect all the climatic information of the location. TMY sets remain in popular use until today providing a relatively concise data set from which system performance estimates can be developed, without the need of incorporating large amounts of data into simulation models. </p><p>TMY sets for 33 locations in Greece distributed all over the country were developed, covering for the first time all climatic zones, for both historical and future periods. Historical TMY sets generation was based on meteorological data collected from the Hellenic National Meteorological Service (HNMS) network in Greece in the period 1985-2014, while the corresponding total solar radiation values have been derived through the Meteorological Radiation Model (MRM).</p><p>Moreover, the generation of future TMY sets for Greece was also performed, for all 33 locations. To this aim, bias adjusted daily data for the closest grid point to the HNMS station’s location were employed from the RCA4 Regional Climate Model of the Swedish Meteorological and Hydrological Institute (SMHI) driven by the Earth system model of the Max Planck Institute for Meteorology (MPI-M). Simulations were carried out in the framework of the EURO-CORDEX modeling experiment, with a horizontal RCA4 model resolution of 0.11<sup>o</sup> (~12 x 12 km). We used daily data for four periods: the 1985-2014 used as reference period and the 2021-2050, 2046-2070 and 2071-2100 future periods under RCP4.5 and RCP8.5 scenarios. </p><p>This work was carried out in the framework of the “Development of synergistic and integrated methods and tools for monitoring, management and forecasting of environmental parameters and pressures” (KRIPIS-THESPIA-II) Greek national funded project.</p>

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