Generative Textiles for Non-Rotary Power Production From Wind

2012 ◽  
Author(s):  
Scott Lux ◽  
Christopher Foster ◽  
Meredith Sellers ◽  
Andrew Friedl ◽  
Carl Feickert ◽  
...  
Keyword(s):  
Probability Distributions ◽  
Human Locomotion ◽  
Small Scale ◽  
Engineering Research ◽  
Design And Optimization ◽  
Wind Energy Generation ◽  
Harvesting Systems ◽  
Practical Engineering ◽  
Wind Simulation ◽  
Operational Envelope

The U.S. Army Engineer Research and Development Center, Construction Engineering Research Laboratory (ERDC-CERL) is developing a new class of flexible, generative textile as a novel means of sustainable wind energy generation. Flexible, generative carbon nanotube (CNT)-based textiles may have excellent potential for electrical capacitive storage and reuse in conjunction with small-scale energy-harvesting systems, both from wind for fixed applications and from human locomotion. This paper describes the design and optimization of a three-layer generative textile composed of discrete layers for generation, distribution, and storage. Initial results suggest that improvement in the generation layer will provide the highest increase in overall performance. The output of the electromagnetic tests shows a power density of 0.17 mW/cm3. However, the efficiency can be significantly improved through increasing the voltage output of the generation layer from 20 mV to around 1V. In an analysis of the operational envelope, wind data collected locally at ERDC-CERL and at other sites around the world reveal close similarity in the probability distributions, which could allow for a practical engineering approach capable of harvesting the steady “ram” component in addition to a variable energy component of the wind. To further study the textile-wind interactions, a wind simulation environment is being developed and has been able to obtain reproducible wind speed data thus far.

scholarly journals Stress-driven two-phase integral elasticity for Timoshenko curved beams

2021 ◽  
pp. 239779142199051
Author(s):  
Marzia S Vaccaro ◽  
Francesco P Pinnola ◽  
Francesco Marotti de Sciarra ◽  
Marko Canadija ◽  
Raffaele Barretta
Keyword(s):  
Solution Procedure ◽  
Small Scale ◽  
Curved Beams ◽  
Sensors And Actuators ◽  
Two Phase ◽  
Design And Optimization ◽  
Local Responses ◽  
Size Dependent ◽  
Classical Boundary ◽  
Phase Integral

In this research, the size-dependent static behaviour of elastic curved stubby beams is investigated by Timoshenko kinematics. Stress-driven two-phase integral elasticity is adopted to model size effects which soften or stiffen classical local responses. The corresponding governing equations of nonlocal elasticity are established and discussed, non-classical boundary conditions are detected and an effective coordinate-free solution procedure is proposed. The presented mixture approach is elucidated by solving simple curved small-scale beams of current interest in Nanotechnology. The contributed results could be useful for design and optimization of modern sensors and actuators.

Design and optimization of small-scale methanol production from sour natural gas by integrating reforming with hydrogenation

2020 ◽  
Vol 45 (59) ◽  
pp. 34483-34493
Author(s):  
Hua Liu ◽  
Jinghui Qu ◽  
Ming Pan ◽  
Bingjian Zhang ◽  
Qinglin Chen ◽  
...  
Keyword(s):  
Natural Gas ◽  
Small Scale ◽  
Methanol Production ◽  
Design And Optimization

Research on Power Flow Control of UPFC Based on PSASP/UPI

2013 ◽  
Vol 385-386 ◽  
pp. 1078-1081 ◽  
Author(s):  
Fang Zhang ◽  
Jian Ping Chen ◽  
Chuan Dong Li ◽  
Yan Juan Wu
Keyword(s):  
Power System ◽  
Flow Control ◽  
Power Flow ◽  
System Analysis ◽  
Unified Power Flow Controller ◽  
Power Flow Control ◽  
Engineering Research ◽  
Good Convergence ◽  
Practical Engineering ◽  
Bus Voltage

The main objective of power flow control for unified power flow controller (UPFC) is to increase the transmission capacity over the existing transmission corridor or line. This paper presents a practical engineering methodology of embedding the power flow control model of UPFC into the commercial software -- power system analysis software package (PSASP) based on its user program interface (UPI) function. In the proposed methodology, the interface currents of UPFC series side and UPFC shunt side between the UPFC device and the network are used to control the transmission line power flow and UPFC bus voltage, respectively. In UPFC series side, the current of UPFC series branch is calculated from the power target equation of the controlled line. In UPFC shunt side, the shunt reactive current of UPFC is used to control the bus voltage. Simulation results on a practical power system show that the proposed methodology can be efficiently applied to the engineering research and analysis of the real power grid with UPFC with good convergence and only one control parameter needed to be prescribed.

Planning a Sustainable, Green Industrial Road with an Ecological Recycling Economy in Mind

2017 ◽  
Vol 42 (3) ◽  
pp. 45-49
Author(s):  
Weiqi Pei
Keyword(s):  
Rural Economy ◽  
Construction Technology ◽  
Engineering Research ◽  
Rational Development ◽  
Ecological Protection ◽  
Recycling Economy ◽  
Practical Engineering ◽  
Planning And Construction ◽  
Ecological Construction ◽  
Rural Construction

With the development of the new rural construction action of beautiful industries, the problem of uncoordinated development of the rural economy and ecological protection has become increasingly prominent. Based on this, in the process of planning, design, construction and management, ecological construction technology was introduced. The planning and design of ecological recycling economy and rural greenway were studied, and the planning types of greenway in industrial villages were deeply explored. Taking the planning and construction of industrial rural greenway in Anji county as an example, the research and analysis were carried out. From the rural road, landscape space, ecology, service facilities, logo and so on, the planning was carried ou, and the greenway network of industrial villages in Anji county was constructed. Combined with practical engineering research, the scientific and rational development of rural greenway in the urban and rural construction throughout the countryn was promoted, the contradiction between urban and rural construction and ecological protection was effectively solved, and the construction of beautiful countryside was promoted.

Design and optimization of acoustic liners with a shear grazing flow: OPAL software platform applications

2021 ◽  
Vol 263 (6) ◽  
pp. 152-163
Author(s):  
Remi Roncen ◽  
Pierre Vuillemin ◽  
Patricia Klotz ◽  
Frank Simon ◽  
Fabien Méry ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Low Frequency ◽  
Small Scale ◽  
Software Platform ◽  
Total Size ◽  
Linearized Euler Equations ◽  
Design And Optimization ◽  
Acoustic Liners ◽  
Frequency Regime ◽  
Grazing Flow

In the context of noise reduction in diverse applications where a shear grazing flow is present (i.e., engine nacelle, jet pump, landing gear), improved acoustic liner solutions are being sought. This is particularly true in the low-frequency regime, where space constraints currently limit the efficiency of classic liner technology. To perform the required multi-objective optimization of complex meta-surface liner candidates, a software platform called OPAL was developed. Its first goal is to allow the user to assemble a large panel of parallel/serial assembly of unit acoustic elements, including the recent concept of LEONAR materials. Then, the physical properties of this liner can be optimized, relatively to given weighted objectives (noise reduction, total size of the sample, weight), for a given configuration. Alternatively, properties such as the different impedances of liner unit surfaces can be optimized. To accelerate the process, different nested levels of optimization are considered, from 0D analytical coarse designs in order to reduce the parameter space, up to 2D plan or axisymmetric high-order Discontinuous Galerkin resolution of the Linearized Euler Equations. The presentation will focus on the different aspects of liner design considered in OPAL, and present an application on different samples made for a small scale aeroacoustic bench.

Prediction of Ultimate Bearing Capacity of Half-Screwed Pile by Integrated Exponential Function Model

2013 ◽  
Vol 353-356 ◽  
pp. 881-885
Author(s):  
Jian Xiong Liu ◽  
Yan Yan Gao ◽  
Xiu Hua Li
Keyword(s):  
Bearing Capacity ◽  
Functional Model ◽  
Ultimate Bearing Capacity ◽  
Model Solution ◽  
Least Square ◽  
Single Pile ◽  
Engineering Research ◽  
Exponential Functional ◽  
Practical Engineering ◽  
Difference Form

This study fitted the measured loading-settlement curve of half-screwed pilewith least square model solution of difference form of integrated exponential functional model, and predict ultimate bearing capacity of half-screwed pile according to the fitted curve of maximum curvature point. Combined with practical engineering research, the study explored the feasibility, rationality and limitations of predicting the half-screwed single pile ultimate bearing capacity with least square model solution of difference form of integrated exponential functional model, and provided the theoretical basis for the popularization and application of the half-screwed pile.

Non-Gaussian probability distributions of solar wind fluctuations

1994 ◽  
Vol 12 (12) ◽  
pp. 1127-1138 ◽  
Author(s):  
E. Marsch ◽  
C. Y. Tu
Keyword(s):  
Solar Wind ◽  
Probability Distributions ◽  
Time Lag ◽  
Small Scale ◽  
Time Lags ◽  
Mhd Turbulence ◽  
Theoretical Concepts ◽  
Fluid Turbulence ◽  
Long Time ◽  
Non Gaussian

Abstract. The probability distributions of field differences ∆x(τ)=x(t+τ)-x(t), where the variable x(t) may denote any solar wind scalar field or vector field component at time t, have been calculated from time series of Helios data obtained in 1976 at heliocentric distances near 0.3 AU. It is found that for comparatively long time lag τ, ranging from a few hours to 1 day, the differences are normally distributed according to a Gaussian. For shorter time lags, of less than ten minutes, significant changes in shape are observed. The distributions are often spikier and narrower than the equivalent Gaussian distribution with the same standard deviation, and they are enhanced for large, reduced for intermediate and enhanced for very small values of ∆x. This result is in accordance with fluid observations and numerical simulations. Hence statistical properties are dominated at small scale τ by large fluctuation amplitudes that are sparsely distributed, which is direct evidence for spatial intermittency of the fluctuations. This is in agreement with results from earlier analyses of the structure functions of ∆x. The non-Gaussian features are differently developed for the various types of fluctuations. The relevance of these observations to the interpretation and understanding of the nature of solar wind magnetohydrodynamic (MHD) turbulence is pointed out, and contact is made with existing theoretical concepts of intermittency in fluid turbulence.

scholarly journals Design and Optimization of Multiple Circumferential Casing Grooves Distribution Considering Sweep and Lean Variations on the Blade Tip

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2401
Author(s):  
Weimin Song ◽  
Yufei Zhang ◽  
Haixin Chen
Keyword(s):  
Pressure Ratio ◽  
Three Dimensional ◽  
Axial Distribution ◽  
Stall Margin ◽  
Design Point ◽  
Casing Treatment ◽  
Design And Optimization ◽  
Practical Engineering ◽  
Engineering Strategy ◽  
Blade Tip

This paper focuses on the design and optimization of the axial distribution of the circumferential groove casing treatment (CGCT). Effects of the axial location of multiple casing grooves on the flow structures are numerically studied. Sweep and lean variations are then introduced to the blade tip, and their influences on the grooves are discussed. The results show that the ability of the CGCT to relieve the blockage varies with the distribution of grooves, and the three-dimensional blading affects the performance of both the blade and the CGCT. Accordingly, a multi-objective optimization combining the CGCT design with the sweep and lean design is conducted. Objectives, including the total pressure ratio and the adiabatic efficiency, are set at the design point; meanwhile, the choking mass flow and the near-stall performance are constrained. The coupling between the CGCT and the blade is improved, which contributes to an optimal design point performance and a sufficient stall margin. The sweep and lean in the tip redistribute the spanwise and chordwise loading, which enhances the ability of the CGCT to improve the blade’s performance. This work shows that the present CGCT-blade integrated optimization is a practical engineering strategy to develop the working capacity and efficiency of a compressor blade while achieving the stall margin extension.

STUDENTS’ INFORMAL HYPOTHESIS TESTING IN A PROBABILITY CONTEXT WITH CONCRETE RANDOM GENERATORS

2020 ◽  
Vol 19 (3) ◽  
Author(s):  
PER NILSSON
Keyword(s):  
Hypothesis Testing ◽  
Teaching And Learning ◽  
Formal Education ◽  
Statistics Education ◽  
Probability Distributions ◽  
Teaching Experiment ◽  
Small Scale ◽  
Uniform Probability ◽  
Data Production

This study examines informal hypothesis testing in the context of drawing inferences of underlying probability distributions. Through a small-scale teaching experiment of three lessons, the study explores how fifth-grade students distinguish a non-uniform probability distribution from uniform probability distributions in a data-rich learning environment, and what role processes of data production play in their investigations. The study outlines aspects of students’ informal understanding of hypothesis testing. It shows how students with no formal education can follow the logic that a small difference in samples can be the effect of randomness, while a large difference implies a real difference in the underlying process. The students distinguish the mode and the size of differences in frequencies as signals in data and used these signals to give data-based reasons in processes of informal hypothesis testing. The study also highlights the role of data production and points to a need for further research on the role of data production in an informal approach to the teaching and learning of statistical inference. First published December 2020 at Statistics Education Research Journal: Archives

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