19e, 190, 20e and 20o which, by virtue of the difference in radii, will rotate at a multiple of the subsystem frequency. The foils of each subsystem are interconnected to move in phase while each foil has at least two degrees of freedom because at least two degrees of freedom are required to induce flutter oscillations. If rods are used of sufficient stiffness to transfer compressional as well as tensile forces, no other support is required but if flexible cables, which will transfer tension but not compression, are used to transfer the motion of the foils to the linkages used in the generation system, they will be pre-stressed by using additional springs, 14g and 14Q, connecting the cables to the frame.
- Infección en los huesos de la rodilla
- Dolor de pecho, especialmente un dolor agudo cuando se respira profundo
- Trastornos del sueño
- Sumerge un paño o toalla en el líquido y aplícalo como compresa sobre la zona afectada
- Inhabilidad para hablar o habla incoherente
- Trestornos de l’articulación temporomandibular
- Enfermedades reumáticas agudas
Pairs of rods or cables, 8£ and 80, are attached to pins, 104 and 103, one each at or near the two ends of the front face of foils 24 and 23, etc. A set of rods, 8£ and 80, and 9e and 9Q, attached to the leading and trailing, even and odd foils respectively, interconnect the subsystems. According to another aspect of the invention, there is provided apparatus for converting the kinetic energy of a fluid stream to useful work comprising a support structure open at opposite ends to permit fluid flow therethrough with a plurality of thin aerofoils and means for mounting these aerofoils within the support structure in a cascade and at zero angle of attack when undisturbed. 1 illustrating the position of the foils subjected to a critical velocity before and after being disturbed; the foils may either be aefodynamically shaped or even flat plates with rounded leading and trailing edges.
Dolor Espalda Pecho
From the foregoing, it will be apparent that the two subsystems are free to oscillate in pitch and plunge relative to each other and that when the entire device is subjected to fluid flows at a critical velocity, adjacent foils will oscillate at approximately 180 degrees out of phase as shown in FIG. 5. Alternating foils are connected by rods or cables, 8e and 8Q at the even and odd leading foil edges and 9e and 90 at the even and odd trailing edges respectively. It is therefore important that the claims of this invention be regarded as including such equivalent constructions and methods as do not depart from the scope of the invention. Accordingly, in order for this velocity to induce flutter oscillations, one or more of the parameters of the system , which includes the generating system, must be varied. FIG. 1 ( b ) shows a system attached to the side of an existing structure, such as a silo or water tower 5. Again, a cylinder 4, in this illustration mounted to the side of the tower 5, houses the linkages, crankshafts and generators.
A circular cylinder 4 mounted above the system contains the linkages, crankshafts and generators to protect them from the elements. Dolor de espalda lado izquierdo inferior . These foils are shown in a horizontal position, but could just as readily be mounted in a vertical position. While the flaps are spring biased to assure the position shown in the figure when at rest, they may be moved due to me fluid dynamic forces of the fluid stream as the foils oscillate in pitch. The oscillatory movement, which occurs at critical velocity, was first observed during studies of the adverse effects of flutter on rotating compressor blades. At velocities above the critical velocity, increases in aerodynamic energy produce great instability and eventually the aerodynamic energy may become so great that the aerofoil is destroyed. This phenomenon involves the interaction of the elastic, inertia and dissipative forces of an aerofoil with the unsteady aerodynamic forces resulting from the movement of the aerofoil in a fluid stream.
Dolor Neuropatico Herpes
Furthermore, because the fluid velocity may vary with time, these parameters must be varied in response to changes in the fluid velocity such that the prevailing velocity will maintain the oscillations. The plates are positioned parallel to the free stream and the aerofoil is at zero angle of attack when undisturbed to define an aerodynamic system. The abscissa is the ratio of to Wa where Wh is the natural frequency associated with pure plunge when V is zero. The vorticity of the wake then feeds back to the aerofoil to introduce a force and movement having components of plus or minus 90 degrees out-of-phase with the aerofoil motion. FIG. 6 is a partial schematic perspective view of a system module with horizontal foils illustrating the mounting of the foils according to the first embodiment and indicating the alternating linkage connections to both the leading and trailing edges of the foils.
The rods or cables extend beyond the frame through holes 13£ and 130, which are sufficiently large to avoid binding, to connect to the generating apparatus (not shown). To vary the parameters of the system, there is provided a control system which includes a detector (not shown), such as an anemometer for wind speeds, for detecting the fluid velocity or one which detects the amplitudes of the oscillations. Field of the invention The present invention relates to techniques and apparatus for using the kinetic energy of a moving fluid stream and more particularly a cascade of aero- or hydro-foils oscillating in such a stream. SUMMARY OF THE INVENTION The present invention extends those disclosed in my earlier patents to improve their efficiency and applicability in naturally occurring fluid streams. FIG. 14 is a schematic sectional view of one embodiment of a propulsive device according to the present invention.
Dolor Muscular En El Pecho
FIG. 11 shows a section of the foils. The parameter S/C, which is the abscissa in this figure, defines the spacing of foils arranged in a cascade where S is the distance between adjacent foils and C is the chord as shown in FIG. 5.etc. are pivotally connected to the respective foils, ¾,· The foils, pins, rods or cables, frame, etc.
This same type of flow results if, instead of a cascade of foils, a flat plate is positioned at s 2 above and beiow the foil. This could be provided directly to the subsystems or applied to the electro-mechanical generating system (not shown here) to which the rods or cables of the subsystems are attached.
Tipos De Dolor De Cabeza
The term “aerofoil” is used in place of the more usual “airfoil” to emphasize this connection and to emphasize the use of such foils in energy generation rather than lift for aircraft. By sequentially varying the angle of attack of the aerofoils, uniform oscillatory motion is produced for reciprocating a rod which then in turn drives an output device. 4. Dolor de espalda especialista . The ordinate is a non-dimensional ratio of the critical velocity for a cascade V(S/C) where adjacent foils oscillate at 180 degrees out of phase, to the critical velocity for a single foil, V∞. As mentioned above, the term “aerofoil” is used for the foils used here for air flows and where the term “hydrofoil” would be used for water flows. 10. While in the previous embodiments, the foils are freely moveable in pitch and plunge, in this embodiment the foils are free only to move in pitch while separate flaps, 393 , 394 , 39·
At a critical velocity (Vc ) this aerodynamic damping component becomes negative and balances the positive mechanical damping of the oscillating aerofoil to provide harmonic oscillations of the aerofoil. This out-of-phase component introduces an apparent damping to the aerofoil. While this phenomenon is well recognized in air, it does have its counterpart in water where, due to the large difference in densities, the amount of energy available in naturally occurring water flows is much larger than that available in naturally occurring air flows. While flutter is not generally observed at naturally occurring water speeds, if the inertia of the system is increased by the use of flywheels attached to the generators or in between the hydrofoils and the generator system, flutter has been experimentally verified for hydrosystems According to one aspect of the invention, there is provided a novel method for converting the kinetic energy of an air flow into useful work by-positioning a cascade of thin aerofoils in a moving stream to define an aerodynamic system.
However, as the windmill, the amount of energy which can be harnessed is limited. According to a further aspect of the invention, there is provided a method for converting the kinetic energy of the fluid stream into useful work by positioning a device including a pair of parallel plates and a thin aerofoil equally spaced from each plate and having at least two degrees of freedom within the fluid stream. FIG. 3 is a graph illustrating how energy can be recovered by introducing a utility device into a system subject to flutter oscillations. Furthermore, such oscillations are due to the Karman vortex street phenomena rather than the aeroelastic phenomenon of flutter. Dolor de espalda y gases . For a particular set of parameters, it can be seen that where S/C is about 1/3, the critical velocity for a cascade is about 1 /2 that needed to produce flutter for the case of a single foil.