Showing papers on "Frustum published in 1980"

Hypersonic Boundary Layer Transition Experiments

Abstract: : New hypersonic wind tunnel data have been obtained to investigate boundary layer transition, with primary emphasis given to tip bluntness and angle of attack effects. The rearward displacement of transition on the cone frustum due to tip bluntness was found to be quite sensitive to free stream Mach number as well as the entropy layer swallowing by the boundary layer. At the highest Mach number obtained in these experiments (M = 9.3), the length of laminar flow could be extended to about nine times the length of laminar flow of a sharp cone at identical conditions. The sensitivity of the maximum rearward displacement of transition with free stream Mach number appeared to be primarily related to local Reynolds number reduction because of pressure losses across the bow shock. Low transition Reynolds numbers typically found on nosetips, extended onto the front portion of the cone frustum. It appears that the still unexplained low transition Reynolds numbers associated with blunt bodies in hypersonic flow includes not only the nosetip region, but the forward portion of the cone frustum. Transition location was found to be sensitive to small changes in angle of attack, and both the sharp and blunt tips produced a rearward movement of transition on the windward ray at small angles of attack. A low supersonic flared nozzle closely duplicated the hypersonic pressure and heat transfer distributions over the nose region of a blunt body.

Coupling unit of two multilayer cables of high-voltage generator stator winding

Abstract: A coupling unit for two multilayer cables of a stator winding of a high-voltage generator, located in the end-face portion thereof, comprises terminations (1) of interconnected multilayer cables, wherein conducting layers (2,10) and conducting layer tubes (6,8) are concentrically arranged and separated from one another by insulating layers (7, 9, 14, 15), jumpers (18, 20, 22, 24) electrically coupling said conducting layers (2, 10) and conducting layer tubes (6, 8). A portion of each insulating layer (7, 9, 14, 15), facing the jumpers (18, 20, 22, 24) has a shape of an end insulation frustum (16). Each jumper (18, 20, 22, 24) is a totality of components made as a portion of a hollow cylinder limited by two planes. Each jumper (18, 20, 22, 24) carries an insulating bushing (12, 21, 23, 25). Thin-walled insulation cylinders (27, 28) are secured in each end insulation frustums (26) and in frustums (26) of the insulation bushings (19, 21, 23, 25). The surfaces of the frustum (26 ) of the insulating bushing (19, 21, 23, 25), the end insulation frustum (16), two adjacent jumpers (18, 20, 22, 24) and conducting layers (2, 10) coupled thereto and conducting layer tubes (6, 8) form an insulation chamber (30). The surface of the jumper (24), the tube (12) of the exterior conducting layer (10) connected to said jumper (24), the end insulation frustum (16), the frustum (26) of the insulating bushing (25), the thin-walled cylinders (27, 28) form an insulation cavity (31). The insulation chambers (30) communicate with one another and with the cooling ducts (5, 13) and with the insulation cavity (31).

Apparatus protecting a lens from airborne particulates

Abstract: During scribing of a ceramic plate with a laser beam, ceramic particles rise from the workpiece in a direction of motion that is generally the same as that of the workpiece. The lens on a laser scriber is protected from abrasive contact with such particulates in the atmosphere by slipping the base of a housing over the circumference of the lens mount and forming a generally airtight seal between them. The housing is shaped like a frustum of a right circular cone, with the apex end thereof truncated and essentially rolled over to form an orifice through which the lens axis and laser beam pass. A plurality of streams of pressurized air are introduced into the housing near the midpoint of the frustum and the lens surface. The air streams are introduced tangent to the inner surface of the housing and angled downward for producing a vortex of air that is exhausted to the atmosphere through the orifice at a velocity and vorticity that inhibits particulates outside of the cover entering the orifice. A suction hose is located in front of the housing for removing particulates from this area. In an alternate embodiment, a directional air lock door is established in front of the lens, with the airstream that establishes the door being directed into a suction hose. The direction of this airstream is preferably maintained the same as the direction that the workpiece moves.

Method of manufacturing semiconductor device provided with complementary semiconductor elements

Abstract: The semiconductor device is provided with semiconductor elements having the complementary characteristics and high breakdown strength. These semiconductor elements are formed in N and P islands respectively each having an inverted frustum shape. Surfaces of the frustum are inclined by an angle determined by semiconductor crystal structure. Side and bottom surfaces of the islands are formed adjacent to an insulating layer and both islands are supported part from the polycrystalline semiconductor layer. All side and bottom surfaces of the islands adjacent the insulating layer are made of high impurity substance of the same type as respective islands.

Method and apparatus protecting a lens from airborne particulates

Abstract: During scribing of a ceramic plate with a laser beam, ceramic particles rise from the workpiece in a direction of motion that is generally the same as that of the workpiece. The lens on a laser scriber is protected from abrasive contact with such particulates in the atmosphere by slipping the base of a housing over the circumference of the lens mount and forming a generally airtight seal between them. The housing is shaped like a frustum of a right circular cone, with the apex end thereof truncated and essentially rolled over to form an orifice through which the lens axis and laser beam pass. A plurality of streams of pressurized air are introduced into the housing near the midpoint of the frustum and the lens surface. The air streams are introduced tangent to the inner surface of the housing and angled downward for producing a vortex of air that is exhausted to the atmosphere through the orifice at a velocity and vorticity that inhibits particulates outside of the cover entering the orifice. A suction hose is located in front of the housing for removing particulates from this area. In an alternate embodiment, a directional air lock door is established in front of the lens, with the airstream that establishes the door being directed into a suction hose. The direction of this airstream is preferably maintained the same as the direction that the workpiece moves.

Gauge for tapered threaded box and pin ends of a joint

Abstract: A thread gauge for determining the proper length, taper, and diameter of a threaded member located on the marginal box and pin end portions of joints of casing or tubing. The threaded member of a joint usually has a thread length which can be defined by the distance the threads extend respective to a vanish point located near the end of the joint. The pin gauge of this disclosure is a conical body which has a smooth internal surface formed between a large and small diameter shoulder. The smooth surface defines a frustum of a cone. The box gauge is a second component of this invention, and has an external tapered surface formed between spaced shoulders which defines a frustum of another cone. Visual observable measuring means on the gauges determine that each of the opposed threaded surface of the joint is of proper length and nominal diameter, and is properly positioned respective to the vanish point of the threads. In one embodiment of the invention, the gauge for measuring both the box and pin ends of a joint is made into a unitary annular member. In another embodiment of the invention, the gauge is made in two separate parts, one part for the pin end and the other part for the box end of the joint.

Method for fitting an optical fiber into an end fitting, the resulting end fitting and a connecting assembly for optical fibers using this end fitting

Abstract: A method for fitting an optical fiber in an end fitting, the end fitting obtained constituting a connection device for connecting to another connecting device incorporating an optical fiber. A hollow cylindrical support whose lateral surface constitutes the reference surface for the position of the fiber is machined and the terminal portion of the fiber is coated with electrolytic gold deposit in the form of a frustum. Then the fiber is self-centered by force inserting the frustum and the terminal portion of the fiber which it covers in the hollow support. Levelling then occurs at the butting face of the fiber by sawing and/or grinding the projecting portions of both the frustum and fiber.

Heat Flow Through Conical Constrictions

Abstract: IN many instances each asperity in a joint formed by two surfaces can be considered to be a frustum of a cone surrounded by either a vacuum or a conducting medium. This paper deals with the numerical solution of the associated heatconduction problem and discusses the results in the light of previous work on constriction resistance. Contents In the study of actual area between contacting surfaces, it is often justifiably considered that the asperities in contact are conical in shape. M For blasted surfaces, for example, the mean of the absolute slope of profile is 0.1 (Ref. 5) implying that, in this case, the asperities in contact may be taken to be the frusta of cones with a semiangle of 80-85 deg. Also in many contact heat-transfer experiments, the contact configuration is of the crossed-wedge type or pyramids contacting flats.6'7 In these instances, it is more reasonable to idealize one side of an individual contact spot by a frustum of a cone fed by a cylinder. As shown in Fig. 1 this conical constriction may be surrounded by either a vacuum or a conducting medium. This paper presents the results of the finite difference solution of the heat-conduction problem depicted in Fig. 1. The results are compared with previous analog and disk constriction results wherever such direct comparison is feasible. The results for the single contact spot may be applied to practical contact geometries in which the number and average size of contact spots can be determined from statistical and deformation considerations. M In each case, the temperature profile obtained from the numerical solution is examined to confirm that the solution indeed represents the physical situations shown in Fig. 1. One such profile is plotted in Fig. 2. A typical error introduced in the finite difference, analog, or indeed any experimental solution of the present problem is due to the axial length of the cylinder being necessarily finite. In the finite difference solution, an examination of the temperature profile reveals whether the total axial length considered is sufficient in relation to the radius of the cylinder and the extent of the conical portion. The constriction resistance may be defined as the ratio of additional temperature drop AT (due to the presence of constriction) to the temperature gradient in the undisturbed field. The resistance is nondimensiona lized by dividing it by the radius b of the feeding cylinder, i.e., R = AT/b(dT/dz)

Ceiling tile replacing and positioning apparatus

Abstract: A ceiling tile replacing and positioning apparatus is disclosed in which a frustum-shaped frame is provided. An encircling flange on the larger base end of the frustum provides a platform upon which the ceiling tile may be rested. Pins project perpendicular to the flange to hold the tile in place. A handle including a sleeve which is pivotally and releasably attached to the frustum-shaped frame at the frustum smaller base makes the apparatus usable from various angles.

The Angle of Fold and the Plastic Work Done in the Folding of Developable Flat Sheets of Metal

Abstract: Under the condition of inextensibility, an initially flat sheet of metal can be folded along straight lines or a curved line to produce various surfaces. The angle of fold and the plastic work done in folding along a line are examined for a series of cases, such as folding-up into a prism and a frustum, folding on a cylinder along a circular arc, and more generally, folding on a developed surface along an arbitrary curved line. Some numerical results are given.

Synthetic resin glass insulating pane

Abstract: A synthetic resin glass insulating pane of, at least, two plates and web frames between the plates, the web edges thereof being welded with the plates. The web frames are provided substantially as tubular bodies. The face edges of the web frames possess outwardly projecting edge shoulders with ultrasonics aligning webs protruding vertically in regard to the face. The side walls of the web frames form the lateral surfaces of a double frustum, the two frusta of which being composed with the smaller faces. The tubes may be straight or inclined tubes and may be of any cross-section. The web frames and/or the plates may be completely and/or partly transparent or non-transparent.

Nonlinear Dynamic Analysis of Frames and Axisymmetric Shell Structures

Abstract: New beam bending element was proposed in Ref. 1) including the effect of shearing deformation, which was composed of two rigid bars connected by two different types of springs. In case of uniform division this discrete element derived by physical consideration is equivalent to the beam element in the conventional finite element method, which was introduced in Ref. 2) by employing linear displacement and rotation functions in conjunction with one-point integration based on the penalty method. Almost the same situation holds for the conical frustum element used for the discrete analysis of axisymmetric shell structures.These discrete elements give accurate linear elastic solutions in spite of their simplicity and they can be effectively used in the limit load analysis because they can construct the plastic collapse mechanisms.In this paper the application of these discrete elements is treated to the nonlinear dynamic analysis of frames and axisymmetric shell structures. As numerical examples nonlinear behavior is analyzed of plane and space frames, circular plates, circular cylindrical shells, and spherical shells loaded impulsively. The obtained results are compared with theoretical solutions, other numerical ones, and experimental results in order to justify the validity of the present method.