スキージャンプ・テイクオフ動作の動的数値流体解析

摘要

スキージャンプテイクオフ動作の最適化を目指し，数値解析と実験による基礎的検討を行った．従来の準動的解析と動的解析を同一対象に適用し比較検討した．その結果前者は，静的な対象の実験とは良好な一致を示すものの，動的な対象の場合には明らかに異なる結果となることがわかった．次に単純なモデルで解析手法の正確さを検証後，テイクオフ動作の動的解析を行った．3種の異なるテイクオフ動作を比較した結果，低い体幹迎角をできるだけ長く維持し，最後に体幹を起こす動作が最適に近いことが明らかとなった．%To optimize the takeoff motion in ski jumping, a fundamental study was conducted by a computational fluid analysis and experiments. The same motion was analyzed by a conventional pseudo-dynamic analysis and by a proposed dynamic fluid analysis. In the case of a fixed model, the former shows a good agreement with the experiment. However, for a moving model the results were apparently different among these two analyses. The accuracy of the proposed dynamic analysis technique was confirmed in the experiment with a simple structure. Then, three different takeoff motions were analyzed. Through this analysis, the optimal condition of the takeoff motion was clarified. The jumper should keep the trunk-angle low as long as possible in the takeoff period.