A simple downburst model is developed for use in batch and real-time piloted simulation studies of guidance strategies for terminal area transport aircraft operations in wind shear conditions. The model represents an axisymmetric stagnation point flow, based on velocity profiles from the Terminal Area Simulation System (TASS) model developed by Proctor and satisfies the mass continuity equation in cylindrical coordinates. Altitude dependence, including boundary layer effects near the ground, closely matches real-world measurements, as do the increase, peak, and decay of outflow and downflow with increasing distance from the downburst center. Equations for horizontal and vertical winds were derived, and found to be infinitely differentiable, with no singular points existent in the flow field. In addition, a simple relationship exists among the ratio of maximum horizontal to vertical velocities, the downdraft radius, depth of outflow, and altitude of maximum outflow. In use, a microburst can be modeled by specifying four characteristic parameters, velocity components in the x, y and z directions, and the corresponding nine partial derivatives are obtained easily from the velocity equations. Oseguera, Rosa M. and Bowles, Roland L. Langley Research Center NASA-TM-100632, NAS 1.15:100632 RTOP 505-66-41...

NASAの精鋭が綴った本作は、ダウンバーストという目に見えぬ脅威を、磨き抜かれた数式で描き出す「空の叙事詩」です。大気の混沌に数学的秩序を与え、航空機の安全という崇高な使命に挑むその姿には、科学が持つ真の美しさが宿っています。わずか四つの要素で荒ぶる風を定義するミニマリズムは、まさに理性の極致と言えるでしょう。 無限回微分可能な関数が織りなす滑らかな風の推移は、複雑な物理現象を一つの流麗な物語へと昇華させています。特異点のない完璧な数理モデルは、自然への深い敬畏と、それを解明せんとする人類の気高き知性を証明しています。空を愛するすべての人へ、目に見えない風の旋律を感じさせる至高の解析ドキュメントです。