Aerodynamics空气动力学.doc

Aerodynamics空氣動力學 Basic Principles基本原理 The popularity and accessibility of paragliding has compelled theoreticians to simplify the fundamentals of aerodynamics so that it can be more comprehensible to everyone. In my attempt to follow this spirit in my book, I will explain Bernoullis general law or principle, along with the concepts of glide ratio and polar curve, all of which will be outlined shortly. It is thanks to its aerodynamic wing that a paraglider is able to fly, and flying speed depends on the shape of the wing, which is specially designed and manufactured. During the launching procedure, as the wing is pulled overhead, air entering from the front fills the wing and internal pressure is built up, thus enabling it to take on its intended shape. The air enters the central part of the wing and circulates to build up pressure in the closed wing tips making a semi-rigid, more or less solid, wing. 飛行傘（滑翔傘）的普及性和可及性使得理論家們不得不簡化空氣動力學的，以便每人理解。我將跟滑比率和曲線一起解釋伯努利一般或者原則。，飛的速度取決於被特別設計並且翅膀的形狀。在，因為翅膀被拉在頭頂，由前面填充進入翅膀和內部的壓力增加，使它能夠呈現的形狀。/，，， At this point, the wing is inflated and aloft. While the wing is flying the air that meets the leading edge (front edge) is forced to separate into two airflows. Due to its design, the wing is almost flat underneath whereas it is curved above.? 此時，傘翼膨脹並且位於高處。當傘翼在飛行中碰上前沿(前緣)的空氣時 被迫分成兩氣。 The lower portion of the separated airflow continues its course smoothly below, while the upper flow follows a larger course over the curved upper surface. The two flows meet simultaneously at the rear of the wing. 被分開的氣流中的較低的部份繼續沿著下面的路線順利的流動，而上面氣流沿著上緣彎曲的表面上的較長路線流動。兩道氣流同時在傘翼的後緣接觸。According to Bernoullis law of physics, accelerated air reduces the pressure the air exerts on a surface, thus there is less pressure on the upper wing side and more pressure on the lower side. Thus due to this difference in pressure the wing acquires lift, an upward force that enables the wing to fly. 根據物理學上的伯努利定律，加速的空氣降低壓力空氣施加於表面，。If we take the analysis a little further,