The windmill is one of the important applications of wind energy and it is one of the best and the easiest ways to manipulate this wind power and use it for water pumping. The best feature of windmills is their high solidity, which gives high torque at the starting. Therefore, they will be able to lunch at low wind speeds like 2 m/s which gives a great possibility of utilizing, especially in the agricultural countries. This feature has been the focus of attention of researchers and developers over the long years. There are several factors affected by it, the most prominent of which is the number of blades and the diameter of the rotor. Some researchers have tested with different models of different diameters and others did on different numbers of blades. The challenge is how to find a model with an ideal number of blades and diameter that can give us the highest torque value under low wind conditions. In this paper, the multi-bladed horizontal axis wind turbines, which are used for water pumping, are discussed. Besides, the literature review is described, which presented the basic design requirements for windmill rotors as solidity, diameter, and tip speed ratio, also information given about materials that used in manufacture. The investigations of this paper are focused on the effect of the number of blades to reach the main goal and the best performance at located wind speeds.
{"title":"A Review of Solidity and Rotor Size Effects on Water-Pumping Windmills","authors":"Omar Abdulkareem Qasim, A. Samancı","doi":"10.52460/issc.2021.029","DOIUrl":"https://doi.org/10.52460/issc.2021.029","url":null,"abstract":"The windmill is one of the important applications of wind energy and it is one of the best and the easiest ways to manipulate this wind power and use it for water pumping. The best feature of windmills is their high solidity, which gives high torque at the starting. Therefore, they will be able to lunch at low wind speeds like 2 m/s which gives a great possibility of utilizing, especially in the agricultural countries. This feature has been the focus of attention of researchers and developers over the long years. There are several factors affected by it, the most prominent of which is the number of blades and the diameter of the rotor. Some researchers have tested with different models of different diameters and others did on different numbers of blades. The challenge is how to find a model with an ideal number of blades and diameter that can give us the highest torque value under low wind conditions. In this paper, the multi-bladed horizontal axis wind turbines, which are used for water pumping, are discussed. Besides, the literature review is described, which presented the basic design requirements for windmill rotors as solidity, diameter, and tip speed ratio, also information given about materials that used in manufacture. The investigations of this paper are focused on the effect of the number of blades to reach the main goal and the best performance at located wind speeds.","PeriodicalId":136262,"journal":{"name":"5th International Students Science Congress","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130440032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, artichoke stem particles (AS) and wollastonite mineral (W) were used as an organic and inorganic fillers in order to improve the mechanical properties of polypropylene (PP). In this regard, PP-based composites containing AS and W were produced as non-hybrid and hybrid materials using a high-speed thermokinetic mixer. Mechanical properties of polymer composites were investigated by the tensile test. Experimental results reveal that the highest elastic modulus for PP-W and the highest tensile strength for PP were obtained while the lowest ultimate strain value was gained using PP-W-A. Then, multiple nonlinear regression analysis was employed to determine the effect of weight ratios of wollastonite mineral and artichoke stem particles in polypropylene on elastic modulus, tensile strength and ultimate strain. Experimental results were expressed second order (tensile strength), third order (elastic modulus) and fourth order (ultimate strain) mathematical models. The results show that the proposed models have well fitted with the experimental results. The coefficient of determination (R2) values were found between 0.95 and 1 in all models. Also, boundedness check control of the proposed models which gives information about whether models are realistic or not was carried out by calculating the maximum and minimum values produced by the relevant model.
以洋蓟茎颗粒(AS)和硅灰石矿物(W)作为有机和无机填料，改善聚丙烯(PP)的力学性能。在此基础上，采用高速热动力混合器制备了含有AS和W的pp基复合材料，分别作为非杂化材料和杂化材料。通过拉伸试验研究了聚合物复合材料的力学性能。实验结果表明，PP- w的弹性模量最高，PP的抗拉强度最高，而PP- w - a的极限应变值最低。然后，采用多元非线性回归分析确定了硅灰石矿物与洋蓟茎颗粒的重量比对聚丙烯弹性模量、抗拉强度和极限应变的影响。实验结果分别用二阶(抗拉强度)、三阶(弹性模量)和四阶(极限应变)数学模型表示。结果表明，所建模型与实验结果拟合较好。所有模型的决定系数(R2)值均在0.95 ~ 1之间。通过计算模型产生的最大值和最小值，对所提模型进行有界性检查控制，给出模型是否真实的信息。
{"title":"Manufacturing and Modeling of Hybrid Polymer Composites by Using Multiple-nonlinear Regression Analysis","authors":"Muhammed Yılmaz, Melih Savran, M. Öncül, K. Sever","doi":"10.52460/issc.2021.035","DOIUrl":"https://doi.org/10.52460/issc.2021.035","url":null,"abstract":"In this study, artichoke stem particles (AS) and wollastonite mineral (W) were used as an organic and inorganic fillers in order to improve the mechanical properties of polypropylene (PP). In this regard, PP-based composites containing AS and W were produced as non-hybrid and hybrid materials using a high-speed thermokinetic mixer. Mechanical properties of polymer composites were investigated by the tensile test. Experimental results reveal that the highest elastic modulus for PP-W and the highest tensile strength for PP were obtained while the lowest ultimate strain value was gained using PP-W-A. Then, multiple nonlinear regression analysis was employed to determine the effect of weight ratios of wollastonite mineral and artichoke stem particles in polypropylene on elastic modulus, tensile strength and ultimate strain. Experimental results were expressed second order (tensile strength), third order (elastic modulus) and fourth order (ultimate strain) mathematical models. The results show that the proposed models have well fitted with the experimental results. The coefficient of determination (R2) values were found between 0.95 and 1 in all models. Also, boundedness check control of the proposed models which gives information about whether models are realistic or not was carried out by calculating the maximum and minimum values produced by the relevant model.","PeriodicalId":136262,"journal":{"name":"5th International Students Science Congress","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130501359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Because of many real problems are better characterized using fractional-order models, fractional calculus has recently become an intensively developing area of calculus not only among mathematicians but also among physicists and engineers as well. Fractional oscillator and fractional damped structure have attracted the attention of researchers in the field of mechanical and civil engineering [1-6]. This study is dedicated mainly a pendulum with fractional viscous damping. The mathematic model of pendulum is a cubic nonlinear equation governing the oscillations of systems having a single degree of freedom, via Riemann-Liouville fractional derivative. The method of multiple scales is performed to solve the equation by assigning the nonlinear and damping terms to the ε-order. Finally, the effects of the coefficient of a fractional damping term on the approximate solution are observed.
{"title":"Approximate Solutions of Nonlinear Pendulum with Fractional Damping","authors":"Sümeyye Sınır, B. Yildiz, B. Sınır","doi":"10.52460/issc.2021.037","DOIUrl":"https://doi.org/10.52460/issc.2021.037","url":null,"abstract":"Because of many real problems are better characterized using fractional-order models, fractional calculus has recently become an intensively developing area of calculus not only among mathematicians but also among physicists and engineers as well. Fractional oscillator and fractional damped structure have attracted the attention of researchers in the field of mechanical and civil engineering [1-6]. This study is dedicated mainly a pendulum with fractional viscous damping. The mathematic model of pendulum is a cubic nonlinear equation governing the oscillations of systems having a single degree of freedom, via Riemann-Liouville fractional derivative. The method of multiple scales is performed to solve the equation by assigning the nonlinear and damping terms to the ε-order. Finally, the effects of the coefficient of a fractional damping term on the approximate solution are observed.","PeriodicalId":136262,"journal":{"name":"5th International Students Science Congress","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121385030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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