亜音速非定常揚力面理論に現われる核関数の改善された数値計算法

抄録

An integral function B(X, r, k) appears in the kernel function for subsonic lifting surface theory. UEDA presented an effcient evaluation method of B. We, however, found that there are some points to be improved. It is seen first that the case "X<0 and k=1" is of fundamental importance. Secondly the least amount of computation should be carried out for a specified accuracy. Some devices for this are presented. Third, the near-field formulationis considerably improved; infinite series expansions are used as restrictedly as possible, and three component blocks are constructed so that they vanish individually for r→∞ and X=0. Fourth, a tentative criterion for the truncation error is introduced in the far-field expression. Eventually an overall computation program of B is presented. It may require the least amount of cornputation in order to attain a specified accuracy. It utilizes the near-field expression provided that the function H is obtainable through a series within a specified number of terms. Some numerical results are quite encouraging.