106 results about "Acoustic streaming" patented technology

An apparatus and method are disclosed in which ultrasonic vibration is used to assist the degassing of molten metals or metal alloys thereby reducing gas content in the molten metals or alloys. High-intensity ultrasonic vibration is applied to a radiator that creates cavitation bubbles, induces acoustic streaming in the melt, and breaks up purge gas (e.g., argon or nitrogen) which is intentionally introduced in a small amount into the melt in order to collect the cavitation bubbles and to make the cavitation bubbles survive in the melt. The molten metal or alloy in one version of the invention is an aluminum alloy. The ultrasonic vibrations create cavitation bubbles and break up the large purge gas bubbles into small bubbles and disperse the bubbles in the molten metal or alloy more uniformly, resulting in a fast and clean degassing.

The invention discloses a microfluidic chip and a cell screening method for screening specific cells. The chip comprises a substrate, a cavity and an acoustic excitation source, wherein the cavity comprises a middle channel, an inlet and an outlet; the acoustic excitation source is positioned on the substrate and at two sides of the middle channel and comprises two parts which extend to a direction of the outlet along the middle channel, wherein the corresponding acoustic resonance frequency of the second part close to the outlet is integer multiples of the corresponding acoustic resonance frequency of the first part far away from the outlet. Based on an acoustic streaming effect formed by targeted microbubbles and asymmetric sound fields, the microbubbles are adhered to the surfaces of the specific cells, so that the enriched cells which flow past the first part can still move in a straight line and cannot diffuse due to a laminar flow characteristic of microfluidics, and the specific cells bonded with the targeted microbubbles can shift because the acoustic resonance frequency of the second part is different from that of the first part. Thus, the screening of the specificity of the specific cells in blood is realized.

The invention relates to an ultrasonic assisted laser electric arc composite welding method of an aluminum alloy. On the basis of carrying out a welding scheme by combining TIG electric arc welding and laser welding, ultrasonic vibration pressure is introduced into a welding seam, wherein a designed vibration head is in direct contact with the welding seam, so that ultrasonic resources can be more sufficiently utilized, and gas in the welding seam can be rapidly escaped; most of gas in the welding seam is removed so that welding seam gas pore defects are reduced or avoided; tissue crystal grains of the welding seam are remarkably refined by utilizing cavitation effect and acoustic streaming effect caused by the fact that ultrasonic waves are transmitted in liquid, and furthermore, tissue alloy elements of the welding seam are more uniform, segregation is reduced, the strength and corrosion resistance performance of the welding seam are improved, and the performance of a welding connector is improved; and welding residual stress is effectively eliminated or reduced and the strength and corrosion resistance performance of the connector are enhanced, so that the efficient welding of the aluminum alloy is realized.

Devices, systems and methods for measuring and detecting properties of a variety of particles or cells in suspension. Properties, such as, for example, velocity of particles, concentration and/or size may be measured according to the methods of the invention. Acoustic energy may be introduced to a focal zone and narrow band interrogating signals may be used. The acoustic energy may cause movement or streaming of the fluid or suspension. The acoustic streaming may allow a Doppler effect measurement without any other source of velocity.

The invention relates to a method for enhancing a gas-liquid process in a micro-reactor. The method comprises the following steps: applying ultrasound of a specific frequency to a gas-liquid micro-reactor in which gas liquid two-phase flow is bubble flow, slug flow, slug annular flow, stirring flow or annular flow; and regulating and controlling the transverse equivalent diameter of a gas phase in the gas-liquid two-phase flow and the ultrasonic frequency till a product of the ultrasonic frequency and the transverse equivalent diameter of the gas phase is up to 1-40 mm.kHz. According to the method, disturbance and acoustic streaming are caused in liquid by using the ultrasound and the cavitation effect of the gas phase, so that gas-liquid mass transfer is enhanced; and meanwhile, agglomeration between a solid or a sticky substance in fluid or the adhesion to the wall surface of a micro channel can be broken, so that blockage is prevented and dredged. The method for enhancing the gas-liquid process disclosed by the invention is suitable for the fields of various gas-liquid reactions, gas absorption, gas separation and purification, and the like.

A probe type acoustic transit-time flow sensor has paired transducers arranged to generate quasi-helical acoustic beams making a plurality of reflective contacts with a pipe's interior wall. The transducers in each pair are spaced apart along the flow axis so that transit-time measurements can be used both to measure the internal diameter of the pipe and to determine a flow rate. These measurements are combined to yield a volumetric flow rate. Various numbers of pairs of transducers can be put on a single probe or on multiple probes and used to provide a more accurate representation of a flow profile and therefore a more accurate volumetric flow determination.

A substrate cleaning method and an apparatus therefor capable of increasing a particle removal ratio at which particles firmly adhering to a substrate are removed therefrom and increasing a throughput. A substrate such as a wafer or the like placed in a cleaning tank filled therein with a cleaning liquid is cleaned by an ultrasonic vibration. Cleaning of the substrate is carried out in such a manner that an ultrasonic vibration is applied to the substrate from a bottom of the cleaning tank, during which application the substrate is kept at a predetermined inclination angle with respect to a direction of acoustic streaming in the cleaning liquid formed by propagation of an ultrasonic wave.

An instrument may continuously monitoring acoustic reflections from within and/or beyond an intubation tube positioned within the mouth of a patient while the patient is breathing. The instrument may include an acoustic reflectometer configured to detect the acoustic reflections. An acoustic flow channel may contain the acoustic reflectometer within it. The acoustic flow channel may be configured to acoustically couple the acoustic reflectometer to an end of the intubation tube, but to substantially block the free flow of expiratory gas from the end of the intubation tube through the acoustic flow channel. A gas flow channel may be separate from the acoustic flow channel and may be configured to allow the free flow of expiratory gas from the end of the intubation tube through the gas flow channel.

The invention belongs to the field of light alloy machining, and particularly relates to a variable frequency ultrasonic semi-continuous casting method for magnesium alloy. The method comprises the steps of alloy smelting, melt delivery and consolidation forming under ultrasonic treatment. Magnesium alloy melt is treated in a real-time variable frequency ultrasonic field introduced in the semi-continuous casting process, and the quasi real-time tracking of the resonant frequency of metal melt is achieved; and liquid cave melt is subjected to the ultrasonic resonance treatment continuously in the whole semi-continuous casting process, so that the continuous ultrasonic high-efficiency treatment of the magnesium alloy melt is achieved in the solidification process. In the method provided by the invention, an ultrasonic radiation rod is extended into the magnesium alloy melt in the magnesium alloy semi-continuous casting process, so that the cavitation effect and acoustic streaming effect produced by the variable frequency ultrasonic field directly act on the magnesium alloy melt solidifying. With the method provided by the invention, the magnesium alloy solidification behavior can be changed obviously, the structure is refined, and the uniformity of the billet solidification structure as well as the mechanical property of magnesium alloy billets are improved; and the billet casting defects are reduced obviously, and the quality of the magnesium alloy billets is improved greatly.

The invention belongs to the field of welding, and relates to a laser welding method combining ultrasonic welding with chilling. According to the method, cooling water is applied to the back surface of a welding seam with a certain distance behind a molten pool in the welding process, and ultrasonic vibration is applied to the front surface; the temperature and the flow of the cooling water are determined according to the welding mode used; and the ultrasonic application position, power and force are adjusted according to the mechanical properties of sample materials. According to the method,the welding residual stress can be effectively reduced, and air holes and cracks are reduced, so that the fatigue performance of the welding seam is improved, and meanwhile, transverse and longitudinal deformation of welding is reduced. Longitudinal residual stress and deformation can be effectively reduced through chilling and welding. The ultrasonic impact can counteract the transverse stress caused by chilling and welding, and further inhibit longitudinal stress, so that deformation is effectively reduced; and the acoustic streaming effect and cavitation effect of the ultrasonic can refinecrystal grains and reduce the air holes and cracks, so that the fatigue performance of the welding seam is improved.

The invention belongs to the technical field of semisolid processing and casting forming of metals/alloys, and in particular relates to a preparation method of alloy semisolid slurry. According to the preparation method, a molten alloy is filled into a slurry container, at least one group of ultrasonic vibration devices is operated in the slurry container, and at least one group of cooling gases is introduced into the slurry container. The alloy semisolid slurry is prepared by changing the parameters of the ultrasonic vibration devices and the quantity of the cooling gases. A round, tiny and uniform non-dendritic crystalline structure can be quickly prepared by combining an ultrasonic acoustic streaming effect with a cooling gas cooling effect, and the introduced inert gas for cooling also a purification effect on the slurry. The preparation method provided by the invention can be used for preparing various kinds of alloy semisolid slurry of aluminum, magnesium, zinc, copper, tin and the like, and is simple, efficient and economical in process, and the prepared slurry is pure and pollution-free.

The invention discloses an acoustic surface wave sorting chip undergoing special wettability optimization. According to the chip, through fusion of some characteristics of wettability optimization, abroadband/variable frequency interdigital transducer technique and hydraulic sorting and an acoustic surface wave sorting method, cell/particle high-flux enrichment and specific cell/particle high-purity sorting are achieved. During working of the chip, effects of a sound field and acoustic radiation force are achieved on fluid and cells/particles in a micro-channel through acoustic surface wave which is generated by an interdigital transducer. Therefore, by implementing special wettability optimization treatment on the base of a sorting channel, differences in surface tension, adhesive force,shear force, wall slippage and the like can be caused in various wettability micro-area interfaces. Cells, which pass through a sorting area in a lined-up form, can deviate away from an original streamline trajectory under actions of an acoustic streaming effect, the acoustic radiation force, the adhesive force (Stokes force) and the like; and through a coupling effect of the special wettabilityoptimization base, deviation speed and distance of the cells/particles is increased, and a sorting flux and efficiency are improved.

The invention discloses an ultrasonic-strengthened generator for an absorption refrigerator. A heater is arranged in a shell; the heater comprises a heat exchange water box and heat exchange tubes; columnar dead holes which extend inwards a box body are distributed on one end face of the box body of the heat exchange water box; condensation ends of the heat exchange tubes 7 are exposed outside the heat exchange water box, and evaporation ends of the heat exchange tubes 7 are arranged in the columnar dead holes; and a solar energy hot water inlet and a solar energy hot water outlet are arranged on the side wall of the heat exchange water box. In the ultrasonic-strengthened generator for the absorption refrigerator, the heat exchange tubes are used as heat exchange elements, and a lithium bromide solution is heated by a heating heat source through the heat exchange tubes, therefore, the heated uniformity of the lithium bromide solution is improved. Furthermore, a group of ultrasonic generators are arranged in the generator for the absorption refrigerator to provide an ultrasonic field for the lithium bromide solution; and the use efficiency of the low-quality heat source and the refrigeration efficiency of the refrigerator are improved by adopting the acoustic streaming effect and the cavitation effect of ultrasonic waves to strengthen a heat and mass transfer process of the lithium bromide solution. The ultrasonic-strengthened generator for the absorption refrigerator can be applied in absorption refrigerators which are driven by the low-quality heat source, such as solar energy, waste hot water, waste gas and the like.

An acoustic transformer for transforming sound waves generated by, for example, a round membrane, into a rectangular wave front with reduced interfering resonances is provided in a form of a waveguide with a generally circular entrance and a generally rectangular exit defined by outer walls. The sound waves, arriving from the radiating membrane, are divided geometrically into two flows of sound waves of generally semicircular cross section. Each of the two flows of sound waves is deformed individually into a rectangular shape. Subsequently, the flows of sound waves are brought together once again at an acute angle. The division of the sound flow of circular cross section into two sound flows of semicircular cross section creates two sound flows, which already have a straight side surface. The two sound flows are passed into curved sound guides, which initially have a generally semicircular cross section and then gradually change over into a generally rectangular cross section. A displacement structure which is approximately elliptical in cross section, thickens gradually and, after reaching a maximum, falls off once again, is disposed to protrude inward of the approximately straight and flat wall of each of the sound guides. Each of the displacement structures along with a corresponding one of the outer walls provides a sound channel, which initially is semicircular in cross section, with a bent cross section of uniform thickness and then stretches into a rectangular cross section at an end thereof.

The invention provides a method and device for directionally solidifying a liquid/solid interface based on ultrasonic wave modulation. In the method, a group of ultrasonic waves is added near a peripheral liquid/solid interface of a crystallizer; the ultrasonic waves spread in a liquid phase to form a sound current; and the sound current forces the liquid phase to flow and stirs the liquid phase. The intensity of the sound current is related to the transmitting power and frequency of ultrasonic waves; and by modulating the transmitting power and frequency of the ultrasonic waves, a flat liquid/solid interface can be obtained. The device has the characteristics that a group of ultrasonic wave transmitting probes are added in a heat insulation layer at the lower end of a furnace, and the probes are externally connected with an ultrasonic signal source. By adjusting the applied ultrasonic waves to accurately control the melt to flow, the radial temperature and solute of the liquid/solid interface are re-distributed uniformly so as to ensure that the solidification material grows in a flat interface manner, the shortcomings are reduced, and the crystal quality and preparation efficiency are improved.

The invention discloses a method for ultrasonic-assisted laser polishing of a ceramic-based composite material. The method comprises the following steps of firstly, grinding and polishing the surfaceof a machined sample wafer of a SiC ceramic-based composite material, and carrying out ultrasonic cleaning; fixing the machined sample wafer on an ultrasonic-assisted laser polishing processing device, and moving a platform to focus the laser to an initial machining position; setting a laser parameter, a galvanometer scanning parameter, an ultrasonic vibration parameter and a motion parameter of an XYZ high-precision mobile platform, starting a femtosecond laser and an ultrasonic generator, and carrying out ultrasonic-assisted laser polishing machining on the machined sample wafer by using theadjusted parameters; and after polishing is completed, carrying out ultrasonic cleaning on the machined sample wafer again. According to the method, the laser machining method and the ultrasonic machining method are combined, the effects of acoustic streaming, cavitation and the like of ultrasonic waves are fully utilized, the problems of defects such as a recast layer and surface cracks caused by the plasma effect and the particle adhesion effect in the laser polishing process are solved, the laser machining process is optimized, and the material removal rate and the polished surface qualityare improved.

The invention discloses a CMT-ultrasonic vibration composite additive manufacturing method. A substrate is ultrasonically vibrated when CMT arc additive manufacturing is performed. After ultrasonic vibration, a fine and uniform component with a non-dendritic structure can be obtained. Under the cavatition and the acoustic streaming effect of ultrasonic vibration, a molten pool is ultrasonically vibrated before solidification, a large amount of fine bubble cores are generated, and the fine bubble cores are reserved to form a core-forming core, so that a solidification structure is refined; andduring the solidification process, the dendritic crystals are broken due to the ultrasonication, so that a fine and uniform structure is formed, and the mechanical property of the component is effectively improved.

A carbon-aluminum interface wetting and structure regulating and controlling device and method under ultrasonic field coupling are provided. The device comprises a vacuum cover, an object stage, a crucible, a radiator, a coupler, a liquid adding device, a heating resistance and a thermocouple; the radiator is connected with the coupler and an ultrasonic power supply; the object stage is assembled together with a thread screw rod and a drive motor; the vacuum cover is communicated with an atmosphere control device, an inert gas system and a vacuum pump system through valves. The method comprises the steps: placing a carbon substrate in the crucible; adjusting an atmosphere in the vacuum cover; adding a metal melt into the crucible, and adjusting the height of the object stage; vacuumizing; introducing an inert gas to the normal pressure; heating through the heating resistance; controlling the carbon substrate to rotate so as to make a metal melt oxide film ruptured; and carrying out ultrasonic coupling of the metal melt. The device and the method are integrated with acoustic streaming and cavitation of an ultrasonic field, and obtain ideal interface structure control conditions through optimization of acoustic field collaborative conditions and optimization of wetting and interface reaction conditions.

The invention provides a hydraulic-acoustic streaming cavitation microbubble generator and a working method thereof. The microbubble generator is suitable for use in mineral slurry mixing. The generator comprises a square Venturi tube bubble generator and an ultrasonic generator, the corresponding positions of the upper and lower parts of the Venturi tube bubble generator are respectively providedwith one air inlet, the corresponding positions of the left and right sides are respectively provided with a contraction zone pipeline and a divergence zone pipeline, and the contraction zone pipeline and the divergence zone pipeline are relatively arranged and corresponding to the two air inlet positions. According to the microbubble generator provided by the invention, pressurized mineral slurry enters the contraction zone pipeline of the Venturi tube from a pipeline, after the mineral slurry enters the divergence zone pipeline from the contraction zone pipeline of the Venturi tube bubble generator, the pressure changes, so that a large amount of air bubbles are generated from the mineral slurry, when the mineral slurry flows towards the divergence zone pipeline from the contraction zone pipeline of the Venturi tube bubble generator, negative pressure is generated, air is sucked into the Venturi tube bubble generator by the two air inlets, and the sucked air is dissolved into the mineral slurry to generate the air bubbles; and the microbubble generator has a simple structure, a good bubble foaming effect, and stronger adaptability to bubble size requirements for sorting of minerals with different fine particle sizes.