This paper discusses the effect of weight on control and gust responses. A fixed-base flight simulator is used to compare three aircrafts, a micro-light airplane, P2V-7 and B-747. The micro-light is shown difficult to fly in severe winds. Much difference is not seen between P2V-7 and B-747. These results agrees with simplified Bode analysis of respective aircrafts.
Optimal paths are shown when a spaceplane skips in the uppermost atmosphere. The flight-path is optimized to give maximum terminal velocity. Typical numerical result shows that the range could be doubled with one jump with the sacrifice of 15% initial velocity.
Take-off performance is calculated for PAR-WIG which utilizes propeller-slipstream. For this purpose, a quick automatic computation scheme is developed for performance of “engine-propeller combination system”. Example calculations are presented, which show that the hump drag is completely removed with PAR effect. It is noted that variable-geomerty of wing-end-plates is desirable and variable-camber of main-wing is essential.
A quick automatic method is presented for computing performance of nonducted propeller with constant revolutional speed. This study is motivated by usefulness for developing WIG vehicles, namely in order to predict propeller data to be used. Results of computation examples show that constant-speed-propellers are considerably robust, viz. insensitive to change of some parameters such as diameter, solidity and rotational speed. It is noteworthy that these well-known properties are confirmed easily and quickly by the present method.
An analysis of a two-dimensional thin airfoil motion is presented, for cases when it flies over and in-proximity-to a wavy-wall surface in an incompressible inviscid flow. Lifting surface technique is used. The results of computation agree satisfactorily with ones of another scheme, which is based on a finite difference method. Efficient integral domain on the wall surface is carefully settled. Some computations are included which suggest effect of many parameters on WIG sea-worthiness.
In this paper a new control technique based on the LAC/HAC concept is proposed to suppress the vibration of flexible space structures. The new technique employs the mechanism to turn on or off the HAC part of the LAC/HAC system in such a manner as to suppress the spillover effects as quickly as possible. The control system designed by the new technique has global stability and is more effective than a pure LAC system, even when an ordinary LAC/HAC system results in failure because of spillover instability. To show the characteristic features of the new technique and how to implement the system, computer simulation examples are given. Finally, the technique is applied to the transversal vibration control of a cantilever beam to show its effectiveness and practicality.