大型長程飛行器為了追求較低的運輸成本和極高的效率而興起翼胴合一飛行器(BWB)的設計概念。這樣的外形相較於傳統航機截然不同，其諸多特性對於傳統航機也有差異，除了空氣動力效率非常突出外，它的安定性似乎並不若傳統飛行器般優良，而造成BWB飛行器在應用上有所限制。 本研究以Fluent和DATCOM兩套數值模擬方法針對BWB飛行器，以NASA開發的機體X-48為基礎進行三維數值運算，探討其空氣動力效率和穩定性，計算並比較不同外形佈局的升阻力比和穩定性參數。我們將使用各種不同的外形來作最佳的模擬計算。並與X-48B相互比較。在網格生成部份，因為是複雜外形，將先以四面體網格來做模擬計算。第二年重心轉移到側風和大雨下的BWB之空氣動力性能模擬。以Fluent程式為主、DATCOM程式為輔，在低雷諾數下，分別以一個穩定側風和以二相流的方法，來模擬側風和大雨對BWB之空氣動力性能影響。 本計畫將特別考慮到未來地球增溫所帶來之高頻率極端天氣現象，以及豪大雨對翼胴合一飛行器(BWB)的強烈性能耗減現象(相對於一般飛機外形而言)，本研究計畫除與國際接軌外，更可以提供飛 機設計參考，計畫執行結果可大幅減低飛機大雨所帶來之危害，亦可提昇我國對國際飛航安全所作之貢獻。 One of the approaches to improving the efficiency of future airplanes is to increase their passenger capacity. Recently, non-conventional designs such as the blended-wing-body (BWB) airplane have been proposed based on earlier flying wing for future air transportation revolutionary improvement. The BWB aircraft is a tailless design that integrates the wing and the fuselage. It is evolutionary conceptual change from the classical design that has been prevailing for the past 50 years i.e. a wing attached to a cylindrical fuselage with a tail to ensure the stability and maneuverability of the aircraft. Conceptually, the main aerodynamic advantage of the new BWB design is its lower wetted area to volume ratio and lower interference drag as compared to the conventional aircraft. Indeed, an increase in (L/D)max of about 20% over the conventional design has been estimated for the BWB aircraft. However, these benefits can only be realized as an improved aerodynamic performance through careful and detailed aerodynamic shape design. This research project plan to use the CFD Fluent and airplane design DATCOM software to precede our own blended-wing-body investigation, and the model airplane shape is similar to NASA X-48. The first year’ work will concentrate on the 3-D model shape simulation by Pro-E, different BWB shapes computations with/without engines or winglets, and aerodynamic efficiency such as L/D ratio and stability derivatives will be compared. The unstructured grid method is implemented due to its robust capability to handle the complex 3-D geometry. Use the above mentioned results as a basis, the work of second year will shift to numerical simulation of severe weather effects (gust wind and heavy rain) on BWB. Implementing our existing 3-D gust wind model and the two-phase flow mechanism of Fluent, both the aerodynamic degradation impact and the flight dynamics stability effect of BWB under the influence of severe weather will be closely simulated. Due to the trend of global warming and more frequent extreme weather situations in the near future, it is believed that current research project is first of its kind in BWB design research. Our research results will not only enhance local aerospace engineering basic research capability, but also contribute to world’s future BWB R&D as an important design reference.