Evolutionary computing methodology for small wind turbine supporting structures

The paper presents a comprehensive, complex, numerical, optimization methodology (computational framework) dedicated for supporting structures of small-scale wind turbines. The small wind turbine (SWT) supporting structure is one of the key components determining the cost of such a device. Therefore, the supporting structure optimization will allow cost reduction and, hence, popularization of these devices around the world. The presented methodology is based on the following: single-objective (aggregation-approach to multi-objective problem) evolutionary algorithm driven optimization, finite-element structural analyses, estimation of wind energy capture efficiency (coupled aero-servo-elastic numerical simulations), and economic evaluation (based on real meteorological data). Then, the methodology is proposed for a guy-wired mast structure of an arbitrary chosen SWT model. The optimization of chosen design features of the structure is performed and as a result the optimal solution for given assumptions is presented and scaling factor for that case is identified (total mass of the foundations). The successful use of combined numerical methods (genetic algorithms, FE method analyses, coupled aero-servo-elastic numerical simulations, pre-/post-processing scripts, and economic evaluation models) is the main novelty of this work

Small Wind Turbines: Specification, Design, and Economic Evaluation

In this work, we consider various aspects of small wind turbines’ (SWTs) design and operation. First, an extensive literature study is presented by considering SWTs specification, market statistics, the smart grid, and the prosumer concepts as well as the most important parameters affecting the efficiency of wind turbines. Then, both the literature review and series of coupled numerical simulations investigating impact of the chosen design solutions on small wind turbine operation are performed. It allowed objective evaluation of different design approaches, which in turn enabled the systematic identification of actual limitations as well as the opportunities for specific design solutions of SWTs: horizontal axis wind turbines (HAWTs) and vertical axis wind turbines (VAWTs); the rotor position in relation to the tower (upwind vs. downwind); and diffusor-augmented wind turbine (DAWT). Additionally, an economic evaluation is carried with the use of an advanced numerical Weather Research & Forecasting (WRF) model. It is shown that auxiliary power generation using privately owned SWTs can be an economically viable option. Finally, a set of design goals for future SWTs is formulated based on the performed numerical analyses

Aero-elastic coupled numerical analysis of small wind turbine-generator modelling

In this paper a practical modelling methodology is presented for a series of aero- servo- elastic-coupled numerical analyses of small wind turbine operation, with particular emphasis on variable speed generator modelling in various wind speed conditions. The following characteristics are determined using the available computer tools: the tip speed ratio as a function of the generator constant (under the assumption of constant wind speed), the turbine coefficient of power as a function of the tip speed ratio (the torque curve is modified accordingly and generator speed and power curves are plotted), turbine power curves and coefficient of power curve as functions of the incoming wind speed. The last stage is to determine forces and torques acting on rotor blades and turbine tower for specific incoming wind speeds in order to examine the impact of the stall phenomena on these values (beyond the rated power of the turbine). It is shown that the obtained results demonstrate a valuable guideline for small wind turbines design process

Experimental Tests, FEM Constitutive Modeling and Validation of PLGA Bioresorbable Polymer for Stent Applications

The use of bioresorbable polymers such as poly(lactic-co-glycolic acid) (PLGA) in coronary stents can hypothetically reduce the risk of complications (e.g., restenosis, thrombosis) after percutaneous coronary intervention. However, there is a need for a constitutive modeling strategy that combines the simplicity of implementation with strain rate dependency. Here, a constitutive modeling methodology for PLGA comprising numerical simulation using a finite element method is presented. First, the methodology and results of PLGA experimental tests are presented, with a focus on tension tests of tubular-type specimens with different strain rates. Subsequently, the constitutive modeling methodology is proposed and described. Material model constants are determined based on the results of the experimental tests. Finally, the developed methodology is validated by experimental and numerical comparisons of stent free compression tests with various compression speeds. The validation results show acceptable correlation in terms of both quality and quantity. The proposed and validated constitutive modeling approach for the bioresorbable polymer provides a useful tool for the design and evaluation of bioresorbable stents

IEEE BigData Cup 2022 Report Privacy-preserving Matching of Encrypted Images

We summarize the results of IEEE BigData 2022 Cup: Privacy-preserving Matching of Encrypted Images - a data mining challenge organized at the KnowledgePit platform in association with the IEEE BigData 2022 conference. We describe the challenge in the hearth of the competition task, as well as the data acquisition and preparation steps. We also provide a brief overview of the top-performing solutions submitted by participants. Finally, we present results of the post-competition data analysis, in which we consider the similarity of solutions submitted by various teams in terms of their errors on the test data. We conclude this analysis by discussion of the significance and impact of the competition results on the underlying problem of constructing effective and efficient anonymization algorithms for monitoring in the DOOH advertising industry.</p