Aerodynamic characteristics of slender winggap-body combinations are studied exactly in the frame of the slender-body theory. Solutions are presented for slender bodies, in which the wing and the body have different incidences with respect to the free stream, and arbitrary width of longitudinal gaps exist between the wings and the body. Expressions of forces derived originally by WARD and relations between the complex velocity and the downwash on a body are extended to the case of multiplly-connected cross sections. Most practical cases encountered by missile aerodynamicists may be covered, and applications to some special cases agree with results obtained by previous writers except for trivial errors. Influences to aerodynamic characteristics of the narror gap width are logarithmic, like many other problems of longitudinal gaps, when the fluid is inviscid.
Tensile test and fracture toughness test at cryogenic temperature were carried out on AA 2014-T6 and AA 2219-T87. The serrated flows observed at rather low temperatures on various aluminum alloys were attributed to the dislocation trapping with interstitial atoms created from the comlex reactions between dislocations. Since the fracture toughness should be determined from the standpoint of the initiation of the crack growth, AE technique which is one of the most useful method for detection of the initiation of the crack growth was used in the present analysis. It seems that the K-values obtained from AE behaviors are strongly affected with the deformation mechanism, because the ratio between Kc and σy is nearly independent of the temperatures.
The optimal regulator utilizing the future value of disturbance input is investigated, to begin with. It is assumed that disturbances can be measured directly without measurement noise and that future disturbances can be previewed with finite preview length. The optimal control law consists of feedforward of convolution integral with respect to future disturbances in addition to orthodox full state feedback. Then, the theory is applied to an aircraft gust alleviation system of longitudinal mode, in which preview of future disturbance can be realized by locating wind sensors forward of the center of gravity. The performance improvement obtained by using this optimal preview regulator is calculated. Numerical results show its effectiveness, especially in case a controller has non-minimum phase lag.
The present study deals with the problem of aerodynamic interference of multi-body combination in rocket-vehicles moving at supersonic or high-subsonic speed. An analysis is made by using slender-body theory for a vehicle composed of a main rocket and two side-boosters, all of them being the bodies of revolution located parallel in a plane. The interference potential functions are obtained as polynomials of sources and sinks for axial flow, and those of doublets for cross flow, applying the MILNE-THOMSON's circle theorem to the flow in each cross-sectional plane. Thus, the variation of normal and side forces acting on the main body and boosters are calculated for a given angle of attack with the change of bank angle., Extension of the present method will make it possible to analyse the case of a vehicle with more than three bodies, e.g., the case of cluster type of vehicle.