1. AbstractFor a well design processes , such as mechanical designs and aerodynamics designs, usually the experimental analysis has a unique preference for the theoretical analysis, however theoretical one is still considered the reference which with we can compare the results.

As the wind energy is considered one of the most effective renewable energy , many researches has been focused on how we can get the optimum energy from the wind, and as a result the lens wind turbine had been created in Kyushu University, japan (Ohya,2008) (fig1).

The aim of this project is to enhance the lens wind turbine design by make an experimental analysis of changing some parameters in the design and the thus reaching the main goal of the design which is aim to obtain a 1KW lens wind turbine with highest performance possible. The experimental analysis that will be introduced through forwarding papers was implemented using ANSYS Fluent, which is a comprehensive computational fluid dynamics tool, and the analysis of Results was implemented using the design expert software.

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Figure 1 Lens Wind turbine (Ohya, 2008)

2.Introduction

There is no doubt that the renewable energy sources such as solar,geothermal,hydropower and wind, are considered the leading of our future in energy generation, as the trend of utilization these sources increases has been increasing from the last decade as shown in figure (fig1), which implement the growing of energy generated in GWH per year globally.

However there are many renewable resources that can be employed to create a clean and effective energy, the wind energy source has been came the most powerful one with not forgetting the solar energy which come at the second place in the research that was prepared at 2011 by the California energy alliance (Alliance). This research showed that the wind energy is predicted to be a significant renewable source of energy in the future due to many reasons such as low cost energy and its sustainability.

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Figure 2 shows the global generated power from renewable energy through last and forecast years (Alliance)

3. Experimental Analysis

As previously mentioned, the main target of this experiment is to obtain an optimum performance of a lens wind turbine (fig 5) that can eventually produce 1KW of power. The required power is obtained from rotating the generator shaft which is coupled with the rotor blades, and the rotor is positioned to be at the throat diameter (fig 4) at which the maximum upwind velocity can be predicted (aerodynamic property of lens), thus our design is focused on how we can obtain this maximum velocity to achieve the optimum power generated by the turbine. So we had been selected the most important parameters that can be changed in our designs which includes (fig 4)the brime height , the outlet diameter , the inlet diameter and the lens width. We also aimed to see the effect of changing these parameters on the drag coefficient, which is important for the structural design of the wind turbine tower.

3 Figure 4 parameters that had been changed during the experiment Figure 5 our design of lens wind turbine that was changed many times during the experiment

3.1 The ANOVA analysis

The factorial ANOVA analysis (tables 6.a & 6.b) had been used in our experiment to determine if one parameter (factor) is more effective than other one or to determine if a combination of two or three parameters is more effective than others , thus we can find the significant factors that will be important in our design and the insignificant factors that will be eliminated from our design case as the insignificant factors implying that there is no great difference among the means of those factors alone (A,B,C or D)(fig4 )or with interaction between them(AB,AC,AD,BC,BD,CD,ABC,ABD,ACD or BCD) and thus there will not be more examination of those means, on the other hand, if significant factors were found , thus a further examination of means will be required, such as the F-value which is compared with F-calculated and from this comparison our hypothesis is accepted or rejected. Our experiment was implemented with four factors (four parameters that previously mentioned), each factor has a number of levels of three except the factor D (The lens width) which has only two levels.

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Table 6.a showing the response of velocity at throttle diameter

Table 6.b showing the response of the drag coefficient

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