Abstract: Separated laminar flow boundary layers are stabilized by delaying a transition into a turbulent flow and by reducing the size of the laminar boundary layer separation zone downstream of a disturbance in the surface contour of a body in the flow, such as a backward step in the body surface, e.g., where sheet metal layers overlap in the surface of an aircraft wing. This purpose is accomplished by suction inlets in the surface just upstream of the disturbance and blowing outlets just downstream of the disturbance and by a flow channel interconnecting these inlets and outlets. Passage of a portion of the flowing medium through these passages is automatically assured due to a pressure differential between the inlets and outlets.

Abstract: Low excitation frequencies of a structural component, for example of a heopter rotor blade or the like, are damped or eliminated by a pendulum device connected to the component, the excitation frequency or frequencies of which are to be damped or eliminated. In a helicopter rotor blade the pendulum device is preferably connected to the blade neck near the rotor head. The pendulum device has a plurality of pendulum bodies coupled to each other for forming a multiple pendulum in which these pendulum bodies are so tuned relative to each other that the multiple pendulum has several eigenfrequencies.

Abstract: A surface type structural component particularly applicable for aircraft, mprises a reinforcing grid structure of longitudinal and cross ribs made of fiber reinforced material. The grid structure is assembled from a plurality of molded box frames or cells. The modular box frames are formed on mold bodies and assembled and bonded together to form the reinforcing grid structure while still on the mold bodies. A laminated sheathing is bonded to the grid structure. Methods and apparatus including an automated assembly plant are disclosed for manufacturing the surface type structural component. The manufacturing plant includes automated handling equipment for molding the box frames on mold bodies, assembling the mold bodies and box frames into grid structures, forming and applying a laminate sheathing, curing and hardening the two-dimensional grid structure and laminate sheathing combination under heat and pressure and removing the mold bodies.

Abstract: A large surface structural component, such as a rotor blade for a windmill r a blade root for a windmill rotor, includes a hollow core (6) of foam material supporting a shell (8, 11) of fiber reinforced synthetic material. Positive templates in the form of disks (5) are inserted into the core (6). These templates are preferably spaced from each other along the length of the structural component and have a shape which defines the cross-sectional contour of the finished component. Thus, initially foam sections having a shape convenient for their production and these templates are assembled on a rotatable arbor (2) which is then rotated in a machining operation such as cutting and/or grinding on a lathe type machine. The shape of these templates (5) provides a guide for the machining operation which is thus substantially facilitated while simultaneously permitting the use of foam cores having initially plane surfaces.

Abstract: A flying body such as an aircraft or a re-entry vehicle is enabled to land substantially horizontally with the aid of one or several glider parachutes also referred to as paragliders, which are stored in an upper body zone and ejected during the landing. The lift capacity of the paraglider is so dimensioned that it replaces the lift loss of the wings due to the low landing speed, whereby the weight of the flying body is kept in equilibrium to the sum of the wing lift and of the paraglider lift. The paraglider resistance or drag is compensated by the engine thrust and an ascending or descending flight is accomplished by modulating the engine thrust.

Abstract: A method and apparatus are disclosed for separating components from a flog medium by means of centrifugal force. The flowing medium travels through two stages. In the first stage a spin is generated and in the second stage the actual material separation is accomplished in one or several separating devices by means of one or several whirling or eddy sources. The apparatus includes a spin generator housing and separator chambers, whereby spin conduits extend into the separator chambers toward exhaust pipes to such an extent that a spacing is provided between the spin conduit and the exhaust pipe. At least one exhaust suction is tangentially effective in the area of this spacing.

Abstract: A thrust nozzle or rather its exit end is tiltable for adjusting or contring the direction of the thrust vector. For this purpose an adjustable ring is movably secured around the exit end of the thrust nozzle. The exit end of the thrust nozzle has a center located on the longitudinal central axis of the nozzle. The adjustable ring also has a center about which it is rotatable. The rotational center of the adjustable ring is also located on the longitudinal central axis of the thrust nozzle. The center of the nozzle end is spaced upstream from the rotational center of the adjustable ring. The adjustable ring rides on the radially outer surface of the nozzle end by way of a slide ring and is adjustable in its position relative to the nozzle end by control rods four of which may be arranged around the circumference of the adjustable ring.

Abstract: The present rotor structure for rotary wing aircraft, such as helicopters, s constructed to minimize the mass unbalance which normally occurs due to the lead-lag of the rotor blades or wings. For this purpose all the bearings supporting the rotors on the rotor heads are constructed as bearings permitting an axial movement of the tension bars which interconnect the wings of a pair of wings. In addition, the wing interconnecting bars are bending-resistant and connected with each other at their crossing point by a centering device which is freely movable in the rotor plane and relative to the rotor head. The connection of the bars by the centering device is rigid in the longitudinal, axial direction of the tension bars.