46 results about "Pressure wave propagation" patented technology

Various apparatus and methods for cleaning teeth and gingival pockets are disclosed herein. A fluid platform can include a pressure wave generator configured to propagate pressure waves through a treatment fluid. The pressure waves may be sufficient to remove undesirable dental deposits from a treatment tooth, neighboring gums, and / or spaces between the tooth and gums.

Various apparatus and methods for cleaning teeth and gingival pockets are disclosed herein. A fluid platform can include a pressure wave generator configured to propagate pressure waves through a treatment fluid. The pressure waves may be sufficient to remove undesirable dental deposits from a treatment tooth, neighboring gums, and / or spaces between the tooth and gums.

According to the invention, elastic parameters, including density, pressure wave propagation speed, and / or shear in pervious layers located in a dense underground area along an array of horizontal positions, are estimated by inverting 4D seismic data. Firstly, an estimate of variations in the elastic parameters in one or more starting positions of the array, which can be located on bored wells within the area in question, is obtained. Then, a propagation algorithm is used in order to gradually carry out the 4D data inversion on the basis of the starting positions. The inversion takes into account the previously estimated parameter variations. A spatial variation in the depth and / or the thickness of the pervious lavers in question can also be taken into account. Propagation is based on positions that are consecutively selected as providing optimal values for a cost function assessed in order to invert the 4D data.

A rotary shutter valve 500 is used for geothermal reservoir stimulation. The valve 500 includes a pressure chamber 520 for holding a working fluid (F) under pressure. A rotatable shutter 532 is turned with a powering device 544 to periodically align one or more windows 534 with one or more apertures 526 in a bulkhead 524. When aligned, the pressurized working fluid (F) flows through the bulkhead 524 and enters a pulse cavity 522, where it is discharged from the pulse cavity 522 as pressure waves 200. The pressure wave propagation 200 and eventual collapse of the bubbles 202 can be transmitted to a target rock surface 204 either in the form of a shock wave 206, or by micro jets 208, depending on the bubble-surface distance. Once cavitation at the rock face begins, fractures are initiated in the rock to create a network of micro-fissures for enhanced heat transfer.

A fuel injection device for supplying high-pressure fuel to an internal combustion engine includes a fuel supply pump, a first common rail and a second common rail. High-pressure fuel is directly supplied to the first common rail and then to the second common rail from the first common rail through a connecting passage having an orifice. The high-pressure fuel accumulated in the common rails is supplied to injectors and is injected into cylinders in a controlled manner. To suppress pressure wave propagation from the first common rail to the second common rail while providing an appropriate flow passage size, a passage diameter of the orifice is set to 0.9 mm–1.3 mm. In this manner, a pressure difference between the first common rail and the second common rail is minimized.

A fuel injection device for supplying high-pressure fuel to an internal combustion engine includes a fuel supply pump, a first common rail and a second common rail. High-pressure fuel is directly supplied to the first common rail and then to the second common rail from the first common rail through a connecting passage having an orifice. The high-pressure fuel accumulated in the common rails is supplied to injectors and is injected into cylinders in a controlled manner. To suppress pressure wave propagation from the first common rail to the second common rail while providing an appropriate flow passage size, a passage diameter of the orifice is set to 0.9 mm-1.3 mm. In this manner, a pressure difference between the first common rail and the second common rail is minimized.

The invention relates to a method for segmental fracturing seaming optimization of a horizontal well with high heterogeneity and tight reservoirs. The method includes the steps of dividing the reservoirs into different levels; using software for simulating pressure wave situations of an interaction layer model which is provided with barrier zones and used for arranging hydraulic fractures after three years of production, obtaining the permeability and corresponding limit width of the barrier zones, and fitting a relationship between the permeability and the corresponding limit width to determine whether not the effective reservoirs on both sides of each barrier zone need to be divided into two independent seepage units; on the basis of judgement on whether or not the economic limit production capacity can be achieved after fracturing for three years, determining the economic limit seepage unit width of the reservoirs different in level; simulating pressure wave propagation situations after three years of production under the condition that different hydraulic fracture spacings are set in the same continuous sand body, and determining the fracture spacings; according to logging interpretation results and reservoir level division standards, dividing a horizontal segment into multiple reservoir units; in combination with the division limit with of the seepage units and reasonablespacing requirements for the fractures of the continuous sand body, setting several hydraulic fracturing seaming schemes for the horizontal segment and preferentially selecting the economical and effective seaming schemes.

The invention discloses a calculating method of the propagation speed of leakage dynamic pressure waves in in-pipe gas. A pipe section where gas flows stably is selected as a pipe section to be measured, and dynamic pressure sensors are installed at the two ends of the pipe section to be measured. A point on the upstream portion or the downstream portion of the pipe section to be measured is selected as a leakage point, and the leakage point is made to leak. Amplitude values of two leakage signals are obtained through signal processing, then sampling points corresponding to the amplitude values are selected, the difference value which is obtained by subtracting the two sampling points is divided by the sampling frequency, and a time difference is obtained. The distance between the sensors is divided by the time difference so that the apparent propagation speed of the dynamic pressure waves can be obtained, and finally, the propagation speed of the dynamic pressure waves is obtained by taking the gas flow speed into consideration. According to the calculating method of the propagation speed of the leakage dynamic pressure waves in in-pipe gas, the theoretical calculating formula of the propagation speed of the leakage dynamic pressure waves can be verified and corrected, the calculation precision of the propagation speed of the dynamic pressure waves is improved, and accordingly a foundation is provided for improving the leakage positioning precision.

A method and system for detecting composition of a physical space comprising: a laser beam source; an acoustic sensor; a beam focusing mechanism for focusing the laser beam at predetermined points in the physical space to generate a thermal inhomogeneity which results in the propagation of a pressure wave that propagates outward from the predetermined excitation point at a propagation velocity approximating the speed of sound for the particular composition of the media; at least one processor for controlling the timing for the laser beam focusing to generate thermal inhomogeneities; whereby the laser focal point is moved sequentially along the light-of-sight at various excitation points by the beam focusing mechanism approximately at the phase front velocity to define a series of predetermined excitation points and pressure wave propagations such that the series of pressure wave propagations combine to produce a coherent pressure wave detectable by the acoustic sensor.

A method for laser shock processing a device, including a metallic body having a surface, comprises conformally applying a compliant solid material to the first region on the surface of the metallic body and applying a layer of ablative material to the second region on the surface of the metallic body. A damping liquid is flowed over the layer of ablative material. An array of pulses of laser energy is directed through the damping fluid to impact the layer of ablative material on the surface and peen the surface in the second region. The pulses induce pressure waves within the metallic body which propagate to the surface in the first region. The compliant solid material acts as a momentum trap, so that the acoustic waves are at least partially coupled into the compliant solid material and attenuated outside of the metallic body.

A rotary shutter valve 500 is used for geothermal reservoir stimulation. The valve 500 includes a pressure chamber 520 for holding a working fluid (F) under pressure. A rotatable shutter 532 is turned with a powering device 544 to periodically align one or more windows 534 with one or more apertures 526 in a bulkhead 524. When aligned, the pressurized working fluid (F) flows through the bulkhead 524 and enters a pulse cavity 522, where it is discharged from the pulse cavity 522 as pressure waves 200. The pressure wave propagation 200 and eventual collapse of the bubbles 202 can be transmitted to a target rock surface 204 either in the form of a shock wave 206, or by micro jets 208, depending on the bubble-surface distance. Once cavitation at the rock face begins, fractures are initiated in the rock to create a network of micro-fissures for enhanced heat transfer.

According to the invention, elastic parameters, including density, pressure wave propagation speed, and / or shear in pervious layers located in a dense underground area along an array of horizontal positions, are estimated by inverting 4D seismic data. Firstly, an estimate of variations in the elastic parameters in one or more starting positions of the array, which can be located on bored wells within the area in question, is obtained. Then, a propagation algorithm is used in order to gradually carry out the 4D data inversion on the basis of the starting positions. The inversion takes into account the previously estimated parameter variations. A spatial variation in the depth and / or the thickness of the pervious lavers in question can also be taken into account. Propagation is based on positions that are consecutively selected as providing optimal values for a cost function assessed in order to invert the 4D data.

A system for determining the concentration of hydrogen in an anode sub-system of a fuel cell system. The fuel cell system includes at least one fuel cell, an anode inlet, an anode outlet, an anode recirculation line, a source of hydrogen gas and an injector for injecting the hydrogen gas. First and second acoustic sensors are provided in the anode recirculation line and are spaced a known distance from each other. A controller that is responsive to the output signals from the first and second acoustic sensors determines the concentration of hydrogen gas in the anode recirculation line based on the time between when the controller receives the sensor signal from the first sensor and receives the sensor signal from the second sensor.

The invention discloses a PWM intermittent spray type variable spraying system characteristic test bench, which is composed of a measurement and control system and a pipeline system. The measurement and control system includes industrial computer, signal conditioning unit, power output module and amplifier. The pipeline system includes diaphragm pump liquid supply device, electronically controlled overflow device, multiple variable spraying units, constant pressure liquid supply branch, constant pressure outlet branch, solenoid valve dynamic characteristic test unit and multi-source pressure fluctuation coupling characteristic test Unit, and set a number of transparent pipeline sections and pressure sensors on the connecting pipeline between the outlet of the diaphragm pump, the inlet of the proportional relief valve, the inlet and outlet of the solenoid valve, the main pipeline and the solenoid valve, so as to use the high-speed image acquisition system or the flow field test system Test the flow field characteristics inside the pipeline and monitor the pressure. The invention can be applied to test the pressure pulsation characteristics of a diaphragm pump, the dynamic characteristics of a proportional overflow valve, the dynamic characteristics of an electromagnetic valve and the propagation characteristics of multi-source pressure fluctuations in pipelines in a PWM intermittent spray type variable spraying system.

An ink-jet recording apparatus includes a pressure chamber that contains ink, a nozzle communicating with the pressure chamber, which ejects the ink from the pressure chamber, an ink-jet head having an actuator that increases and decreases the capacity of the pressure chamber, and a driving signal generation unit that supplies the actuator with a driving signal to eject an ink drop from the nozzle. When no ink is ejected from the nozzle, the actuator is supplied with a very low pressure driving signal to increase the capacity of the pressure chamber and then return the increased capacity to an original size. The pulse width of the very low pressure driving signal is about twice as long as a pressure propagation time period during which a pressure wave in the ink propagates through the pressure chamber.