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.
In numerical lifting surface calculations, assessment of convergence characteristics of number-sequences is a difficult task. Methods are investigated which needs no comparisons with other schemes. Among several kinds of convergence, the "N-r type" appears often in our practical investigations. For this type, a formulation is presented which gives a solution having a specified accuracy without iterative processes. It is an important requirement in order to save computation time. As a demonstrative model, a new method of chordwise quadrature "TrTr-NONEQ" is presented. This model verifies that the general formulation is sufficiently reasonable. In addition TrTr-NONEQ exhibits many advantages over other current, such as WAGNER'S, GAUSS' and CUNNINGHAM'S, methods.
For the purpose of measuring the miss distance between a flying body and a target, DOPPLER type MDI (Miss Distance Indicator) is populanly used because of its theoretically high accuracy of measurement and simplicity of the system. However, this system has one drawback in that its accuracy is reduced when the flying body changes its velocity as it passes by near the target. Possibility of a measuring system free from this drawback while retaining high measunement accuracy of the original system was investigated, which resulted in a system that provides measurement of miss distance by the use of time integration data of DOPPLER frequency only even When the flying body is flying at a fixed acceleration. The measurement error was also investigated and it was found that operating radiowave length error, DOPPLER frequency integration error, DOPPLER frequency integration time error and other factons responsible for the measurement error are all negligibly small. Numerical calculations conducted to verify feasibility of this measurement system demonstrated that this system has significantly improved measurement accuracy over conventional system and that it can provide accurate miss distance measurement of flying bodies even when they are flying at changing velocity.