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Showing papers on "Heat sink published in 1968"


Journal ArticleDOI
TL;DR: The VAPOR HEAT PIPE as mentioned in this paper is a closed, EVACUATED CHAMBER, whose interior wall is filled with a volatile fluid, which is used for transferring heat energy from one end of the pipe to the other.
Abstract: THE HEAT PIPE IS ESSENTIALLY A CLOSED, EVACUATED CHAMBER WHOSE INSIDE WALLS ARE LINED WITH A CAPILLARY STRUCTURE, OR WICK, THAT IS SATURATED WITH A VOLATILE FLUID. THE OPERATION OF THE HEAT PIPE COMBINES VAPOR HEAT TRANSFER AND CAPILLARY ACTION. VAPOR HEAT TRANSFER IS RESPONSIBLE FOR TRANSPORTING THE HEAT ENERGY FROM THE EVAPORATOR SECTION AT ONE END OF THE PIPE TO THE CONDENSER SECTION AT THE OTHER END. CAPILLARY ACTION IS RESPONSIBLE FOR RETURNING THE CONDENSED WORKING FLUID BACK TO THE EVAPORATOR SECTION. THE VAPORIZED FLUID STORES HEAT ENERGY AT THE TEMPERATURE AT WHICH THE VAPOR WAS CREATED AND WILL RETAIN THE ENERGY AT THAT TEMPERATURE UNTIL IT MEETS A COLDER SURFACE. THIS TENDENCY TO RESIST ANY DIFFERENCE IN TEMPERATURE WITHIN THE HEAT PIPE IS RESPONSIBLE FOR THE DEVICE'S HIGH THERMAL CONDUCTANCE. THE HEAT PIPE CAN OPERATE AGAINST GRAVITY AND WITHOUT A SECOND EXTERNAL ENERGY SOURCE. DEVICES THAT OPERATE ON THE PRINCIPLE OF VAPOR HEAT TRANSFER CAN HAVE SEVERAL THOUSAND TIMES THE HEAT-TRANSFER CAPACITY OF THE BEST METALLIC CONDUCTORS. HEAT PIPES HAVE BEEN MADE TO OPERATE AT VARIOUS TEMPERATURES SPANNING THE RANGE FROM BELOW FREEZING TO OVER 3,600 F. THE POWER TRANSFERRED RANGES FROM A FEW WATTS TO MORE THAN 17,000 WATTS. THE HEAT PIPE IS A UNIQUE AND VERSATILE HEAT-TRANSFER DEVICE. ITS SPECIAL PROPERTIES ARE HIGH THERMAL CONDUCTANCE, TEMPERATURE FLATTENING, HEAT-FLUX TRANSFORMATION AND SEPARATION OF HEAT SOURCE FROM HEAT SINK.

142 citations


Patent
04 Apr 1968

97 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of secondary fluid injection through single nontangential slots on surface heat transfer in regions near the injection site was studied, and experimental results were obtained which cover the range of interest of these parameters for many situations encountered in film cooling applications.
Abstract: A study of the effect of secondary fluid injection through single nontangential slots on the surface heat transfer in regions near the injection site is presented. The nondimensional parameters governing the heat transfer are obtained from the pertinent differential equations, and experimental results were obtained which cover the range of interest of these parameters for many situations encountered in film cooling applications. The experimental heat transfer rates were obtained from a novel transient test facility, and are presented as ratios of the heat transfer obtained with film injection to the heat transfer obtained with only the single mainstream.

62 citations


Patent
James Brennan1
31 Dec 1968
TL;DR: In this article, the temperature of a matrix of air isolated semiconductor means is sensed by a diode diffused in an adjacently mounted integrated circuit immediately prior to the print cycle and the power applied to drive the matrix during the printing cycle is adjusted in accordance with the offset voltage across the diode.
Abstract: A high speed electronic display system having a circuit for adjusting the power applied to a thermal display matrix during a printing cycle based upon the temperature of the print head. In one embodiment, the temperature of a matrix of air isolated semiconductor means is sensed by a diode diffused in an adjacently mounted integrated circuit immediately prior to the print cycle, and the power applied to drive the matrix during the print cycle is adjusted in accordance with the offset voltage across the diode. In another embodiment, the temperature of the matrix of elements is estimated using a temperature sensing element located on the heat sink and correcting the sensed temperature to compensate for the repetition rate of the print cycle, the number of elements activated during each print cycle, the rate at which heat is transferred to the heat sensing element, and the rate at which heat is dissipated from the heat sensing element. There is a single sensor for the thermal display matrix.

38 citations


Patent
16 May 1968

37 citations


Patent
16 Apr 1968

30 citations


Patent
15 Aug 1968
TL;DR: In this article, the authors describe a process in which a large number of different types of devices are assembled in a standard MOSETting Plastic by a process that includes the use of transfer molds.
Abstract: A PLURALITY OF SEMICONDUCTOR DEVICES ARE ENCAPSULATED SIMULTANEOUSLY IN A THERMOSETTING PLASTIC BY A PROCESS THAT INCLUDES THE USE OF TRANSFER MOLDING TECHNIQUES. DISCRETE SEMICONDUCTOR DEVICES, SUCH AS TRANSISTORS, ARE STRIP MOLDED AS A UNIT AND SEPARATED AFTER THE THERMOSETTING PLASTIC HAS CURED. PRIOR TO THE MOLDING PROCESS, AN ARRAY OF LEAD WIRES INTERCONNECTED BY PARTIALLY SHEARED TIE-BARS ARE STAKED TO INDIVIDUAL HEAT SINKS ALSO FORMED IN A STRIP. A SEMICONDUCTOR DEVICE IS MOUNTED TO EACH OF THE INDIVIDUAL HEAT SINKS AND WHISKER LEAD WIRES ARE BONDED TO THE ACTIVE REGIONS OF THE DEVICE AND THE LEAD WIRES. TO PREVENT CONTAMINATION OF THE SEMICONDUCTOR JUNCTIONS WITH ATMOSPHERIC IMPURITIES, THE WAFERS ARE COATED WITH A PROTECTIVE MATERIAL. GROOVES ARE COINED INTO THE HEAT SINK TO LIMIT THE WAFER COATING MATERIAL TO A RESTRICTED AREA. AFTER THE STRIP MOLDING STEP HAS BEEN COMPLETED, THE INDIVIDUAL SEMICONDUCTOR DEVICES ARE SEPARATED BY CUTTING THE TIE-BARS AND SAWING THE INDIVIDUAL HEAT SINKS.

29 citations


Patent
18 Dec 1968
TL;DR: In this paper, a cooling structure for pressure mounting electrical components having opposed contact surfaces was proposed, wherein spring clamp means electrically insulated from and in clamping engagement with the edges of oppositely disposed heat dissipating members, urges the members together to provide a pressure mounting heat sink for an electrical component disposed therebetween.
Abstract: A cooling structure for pressure mounting electrical components having opposed contact surfaces wherein spring clamp means electrically insulated from and in clamping engagement with the edges of oppositely disposed heat dissipating members urges the members together to provide a pressure mounting heat sink for an electrical component disposed therebetween; the spring clamp means externally applying and maintaining a predetermined force on the component to effect the proper electrical and thermal contact between the component and the heat dissipating members.

27 citations


Patent
02 Jan 1968
TL;DR: In this article, a power meter for measuring radiation including a radiation target disc, a heat sink for cooling the periphery of the disc, and a circumferentially extending array of radial thermocouples was presented.
Abstract: A power meter for measuring radiation including a radiation target disc, a heat sink for cooling the periphery of the disc, and a circumferentially extending array of radial thermocouples for measuring the total power of energy incident on the central area of the disc as a function of the sum of radial temperature gradients of the disc.

26 citations



Journal ArticleDOI
J.G. Josenhans1
01 Apr 1968
TL;DR: A series combination of three IMPATT diodes mounted on a diamond heat sink produced a C3V 13 GHz output of 4.5 watts with an efficiency of 6.4 percent as mentioned in this paper.
Abstract: Series connections of IMPATT diodes are capable of giving high microwave power output at a reasonably high impedance level. The series combination avoids many of the stability problems associated with parallel combinations. A series combination of three diodes mounted on a diamond heat sink produced a C3V 13-GHz output of 4.5 watts with an efficiency of 6.4 percent.

Journal ArticleDOI
TL;DR: In this article, the authors delineated important heat transfer mechanisms and determined the dependence of heat transfer on fuel vapour properties, and showed that fuel consumption rates, for the diameter range of interest, are determined primarily by nonradiative rather than radiative heat transfer.

Journal ArticleDOI
TL;DR: In this article, an analysis has been made on the Angstrom's method to determine the thermal diffusivity of solids when the size of the specimens are comparatively small, and the equation of thermal conduction was solved under boundary conditions that the temperature was varied sinusoidally at one end of the specimen and was constant at the other end connected to a heat sink.
Abstract: An analysis has been made on the Angstrom's method to determine the thermal diffusivity of solids when the size of the specimens are comparatively small. The equation of thermal conduction was solved under boundary conditions that the temperature was varied sinusoidally at one end of the specimen and was constant at the other end connected to a heat sink. The solution shows that there exist temperature waves propagating along the specimen, attenuating gradually, and being vanished completely at the end connected to the sink. Expressions to determine the thermal diffusivity by measuring the attenuation or the phase difference of the waves at two positions along the specimen have been derived. An apparatus to determine the thermal diffusivity of N-type germanium has been measured at room temperature. The experimental results showed a good agreement with those computed numerically using the present analysis.

Patent
Alexander L Pugh1
19 Sep 1968
TL;DR: In this article, a control for disrupting and permitting the flow of the output beam of a laser to a workpiece is presented, which includes a shutter mounted in the path of the beam and movable between a position in which the shutter extends across the path, so as to disrupt the beam, and a position where the beam is allowed to pass the shutter.
Abstract: A control for disrupting and permitting the flow of the output beam of a laser to a workpiece. The control includes a shutter mounted in the path of the output beam and movable between a position in which the shutter extends across the path of the output beam so as to disrupt the beam, and a position in which the beam is allowed to pass the shutter. A metal heat sink surrounds the shutter. When the shutter extends across the path of the beam, the shutter deflects the beam against the surface of the heat sink which dissipates the heat developed by the beam.



Patent
14 Oct 1968
TL;DR: In this paper, a heat sink and holding device for soldering a plurality of electrical leads is described, which consists of two spring clips of high heat conductive material connected to a base of heavy material and having a nonskid bottom.
Abstract: A heat sink and holding device for use in soldering a plurality of electrical leads. The complete array of electrical leads is connected to a common heat sink which also holds all of the leads while each lead is soldered individually. The device comprises two spring clips of high heat conductive material connected to a base of heavy material and having a nonskid bottom. One of the spring clips comes in contact with each wire lead and acts as the main heat sink portion. The other spring clip acts primarily as a holder.

Patent
09 Dec 1968
TL;DR: In this article, a foot portion is bent up from a planar, electrically conductive heat sink, and a header rigidly mounting circular cross section electrical leads positions one of the leads in engagement with the foot portion.
Abstract: A foot portion is bent up from a planar, electrically conductive heat sink, and a header rigidly mounting circular cross section electrical leads positions one of the leads in engagement with the foot portion. A semiconductor crystal is attached to the heat sink with a soft solder and a contact having an upstanding flange is similarly attached to the semiconductor crystal with a soft solder. The flange is attached to an electrical lead positioned by the header. A pliant, substantially fluid impervious material, such as silicone rubber, is cured around the semiconductor crystal and a casement is then molded to the leads and heat sink to form a shock and strain resistant semiconductive device. The header is in one form enclosed by the casement, but in alternate forms may be partially or entirely stripped after molding.

Patent
05 Aug 1968

Patent
23 Dec 1968
TL;DR: The critical point heat pipe can serve as an auxiliary heat transport device for supplying heat from the exhaust gases of a vehicle engine to the vehicle compartment heat exchanger during engine warmup as discussed by the authors.
Abstract: The employment of a heat pipe as a passive, self-operating thermal energy transport valve which automatically thermally couples a heat source to a heat sink or decouples the same depending upon the operating temperature of the heat pipe and its relation to the critical point of the working fluid. The critical point heat pipe can serve as an auxiliary heat transport device for supplying heat from the exhaust gases of a vehicle engine to the vehicle compartment heat exchanger during engine warmup.

Journal ArticleDOI
TL;DR: In this article, a thermal-transmission apparatus for textile materials up to at least 1 in. thick is presented, which works on the principle that for conductors in series with respect to direction of heat flow, the ratio of the temperature drop across them equals the temperature resistances, and the only measurements involved are those of temperature in the equilibrium state.
Abstract: Details are given of a new thermal-transmission apparatus which is automatic in operation, which does not depend on the measurement of a heat flux, and which requires no guard plates to eliminate edge heat losses. The apparatus works on the principle that for conductors in series with respect to direction of heat flow, the ratio of the temperature drop across them equals the ratio of their thermal resistances, and the only measurements involved are those of temperature in the equilibrium state. The apparatus is suitable for testing the thermal-transmission properties of textile materials up to at least 1 in. thick. Data are presented for the thermal-transmission properties of timber and of plate glass determined with the new apparatus.




Patent
23 Sep 1968
TL;DR: An oil and air cooled rotating spindle as discussed by the authors can be maintained at or near ambient temperature, thus preventing any changes in temperature of the apparatus rotated by the spindle and hence in any material contained in the apparatus.
Abstract: An oil and air cooled rotating spindle. By means of an oil flow path, heat sinks and air-cooled surfaces, the spindle during operation may be constantly maintained at or near ambient temperature thus preventing any changes in temperature of the apparatus rotated by the spindle and hence in any material contained in the apparatus.

Patent
08 Aug 1968
TL;DR: In this paper, a method for controlling the heating and cooling steps in adhesive bonding of helicopter rotor blades and similar articles containing metal masses which serve as heat sinks is presented, where local heaters, which roughly define separate zones of a metal pressure fixture, are separately energized to raise the zone temperatures unequally, to compensate for the local drain of heat into the heat sink.
Abstract: Method for controlling the heating and cooling steps in adhesive bonding of helicopter rotor blades and similar articles containing metal masses which serve as heat sinks. To bring the temperature at the adhesive bond line equally to flow temperature, local heaters, which roughly define separate zones of a metal pressure fixture, are separately energized to raise the zone temperatures unequally, to compensate for the local drain of heat into the heat sink. For cooling, liquid is pumped through passages while the local heaters cycle on as required to equalize the rate of cooling.

Journal ArticleDOI
01 Mar 1968
TL;DR: In this paper, the advantages of the sheet structure for CW operation are pointed out and curves for determining the temperture of the device at thresold are presented as a function of device parameters.
Abstract: CW operation of a sheet Gunn oscillator is reported. The advantages of the sheet structure for CW operation are pointed out. Also, curves for determining the temperture of the device at thresold are presented as a function of the device parameters.

Patent
05 Jun 1968
TL;DR: A heat transfer system for supplying a constant temperature to a heat utilization device including a heat transfer pipe having the utilization device mounted intermediate an alpha emitting radioisotope fuel for vaporizing the working fluid of the heat pipe and a heat exchanger for dissipating excess heat from the condenser portion of a heat pipe was proposed in this paper.
Abstract: A heat transfer system for supplying a constant temperature to a heat utilization device including a heat transfer pipe having the utilization device mounted intermediate an alpha emitting radioisotope fuel for vaporizing the working fluid of the heat pipe and a heat exchanger for dissipating excess heat from the condenser portion of the heat pipe, means for retaining helium generated by the radioisotope fuel and a passageway for transporting the helium to the interior of the heat pipe to maintain constant the internal pressure and vaporization temperature of the working fluid within the heat pipe as the rate of heat dissipation from the radioisotope decreases

Patent
23 Dec 1968
TL;DR: In this article, a plug for rocket motor plug nozzles has a shell constructed of a thermally anisotropic material, bulk preoriented pyroltic graphite, oriented to serve as both an insulator and as a heat conductor to divert heat to various heat sinks.
Abstract: A plug for rocket motor plug nozzles has a shell constructed of a thermally anisotropic material, bulk preoriented pyroltic graphite. The shell material is oriented to serve as both an insulator and as a heat conductor to divert heat to various heat sinks. Resilient fastening means are employed to allow relative movement of parts to minimize the effects of thermal stresses.

Patent
21 Aug 1968
TL;DR: In this paper, the authors describe underground high voltage cables consisting of at least one conductor spaced from a sheath with cooling gas flowing axially in the space between the two, so that part of the heat generated in the cable is conducted away from the cable by heat sinks, which are natural such as ponds; or artificial such as radiators.
Abstract: 1,124,081. Cable systems. UNITED KING- DOM ATOMIC ENERGY AUTHORITY. 11 Feb., 1966 [25 Feb., 1965], No. 8115/65. Heading H2C. [Also in Division H2] Underground high voltage cables consist of at least one conductor spaced from a sheath with a cooling gas flowing axially in the space between the two, so that part of the heat generated in the cable is conducted away from the cable by heat sinks, which are natural such as ponds; or artificial such as radiators. The gas may be nitrogen or a 3 : 1 mixture of sulphur hexafluoride and nitrogen. As shown, the cable has a non-magnetic pressure-tight sheath 1 in which a conductor 2 is supported by polyethylene spiders 3. The conductor is coated with polythene 4 to improve its impulse resistance. The coating may be metallized adjacent the conductor so as to minimize voids. A similar coating may line the sheath. The system is provided (Fig. 2, not shown) with spaced pumping stations, blocking members (7) being provided to stop the pump from feeding back to itself, and the pumping stations may incorporate filters and radiators.