車載風力發電機的創新設計

Abstract

舉凡各類載具如車輛、船舶或航空器等難免會以成本或外觀為重要設計的參數與目標，但這些設計的考量往往忽略阻力所產生的油耗問題，其間存在著相互矛盾的地方。若能「化阻力為助力」，設法利用加諸於車體迎風面之風阻，轉換成有效之能量，亦是一種能源再生的方法。 本研究主要目標為建構可裝設在車體外部的一種車載風力發電機，設法在行進間擷取有效地風能，將其轉換為可應用的電能。前提為: 1.儘可能不額外增加車輛在行進時所產生之空氣阻力，2.儘可能不破壞車體原有外觀。為驗證在車輛上裝設一風機之可行性，首先以一般小轎車為例，利用流體力學分析軟體ANSYS CFX，分析車輛在特定相對風速下，其車輛周圍的流場分佈情況，評估在車體外部可裝設風機之最適當位置。 分析結果顯示，在車頂與引擎蓋處擁有較高相對風速，但因安全性與造成風阻係數增加等因素下暫不考慮此處，車尾處雖不是最高風速產生區，但是配合車體外部之導流板如尾翼，讓尾翼與後行李廂蓋之間形成一流道，利用尾翼所產生的氣動力而加強空氣流速特性，藉由此流道內產生之加速氣流讓葉片旋轉，此處經模擬與評估為車輛外部最佳擺放處。此外，由分析與實驗結果顯示，在行車時速30∼50km/hr範圍時，尾翼攻角接近 9°可使風機的扭矩性能，較未加裝尾翼時提升約15%；本研究又進一步將尾翼創新改良成為上凸圓拱型尾翼，其與一般傳統型尾翼相比，風機扭矩性能可再增加約4%。為了驗證本研究分析模型與結果的正確性，本研究同時建構組裝車載風機性能的動態量測設備；且由實驗數據與分析結果一致均顯示，所研發的新型尾翼搭載風機系統的設計，證實可有效地提昇車載風機組的發電效能。

The common target for vehicular industry, as auto motor, ship, or aircraft, always focuses on minimum cost, lowest fuel consumption, and optimal performance, but many contradictions exist and conflict with each other. So, if it can effectively retrieve the wind energy flow through the car body and transfer it to be useful power. It may say that "Transforming obstacles into benefits ", also a kind of the good way for doing the energy renewable. The aim of this study is to develop a wind turbine system for vehicular application. There are some premises of the study: 1. try to not to increasing the air resistance , 2. no need to retrofit the vehicle. For verifying the feasibility and efficiency of the proposed wind turbine installed on the vehicle. This study is using the CFD simulation software as ANSYS CFX to analyze the flow field of the airflow around the side contour of vehicle , trying to investigating the most appropriate position on the car for installing the device of the wind turbine. From the results of the air flow analysis, the tail area is generally not the position with the highest speed of wind. But the efficient jet flow will be induced between the tailgate and the rear wing based on the principle of the aerodynamic of air flow through the exterior body of the car. Aerodynamic characteristics of the rear wing could augment air flow speed from airfoil shape , the augment air flow make the blade rotate. From the results of the simulation can be considered as an evidence to support that tailgate is the most appropriate installation position of the wind turbine for vehicular application. In addition, when the driving speed is setting around 30 ~ 50 km/hr, the attack angle of the rear wing is 9 °, then the torque performance of the wind turbine will increase about 15% as compared with non rear wind situation. More over, under the investigation of the study, the torque of the blade will increase 4% more, if shrouded type rear wing is developed and adopted. In the study, the full scale wind power experimental system is designed for evaluation of the simulation analysis model. Both the analysis and experimental data are demonstrated the practical and efficient performance of the innovative car used wind turbine system proposed in the study.