10 results about "Oscillating flow" patented technology

Techniques described herein involve an electronics-free downhole flow sensor. For example, a system can include a receiver positioned at a surface of a wellbore. A flow sensor can be positioned downhole in the wellbore. The flow sensor can include a wire positioned within a flow path of downhole fluid in the wellbore. The wire can oscillate based on flow of the downhole fluid. The flow sensor can also include a variable reluctance sensor that can detect an electrical signal that is generated by oscillation of the wire. The variable reluctance sensor can transmit the electrical signal to the receiver. The receiver may determine a resonant frequency based on the electrical signal and may determine a fluid velocity of the downhole fluid based on the resonant frequency.

A mechanical ventilator includes an oscillating flow controller, a respiratory interface, and an accumulator having a first variable volume chamber fluidly coupled to a bi-directional fluid port of the flow control valve, a second variable volume chamber fluidly coupled to the respiratory interface, a displaceable diaphragm fluidly separating the first variable volume chamber from the second variable volume chamber, and a biasing element configured to bias the diaphragm in the direction of the first variable volume chamber. In use, the oscillating flow controller provides an oscillating fluid output to the accumulator, thereby causing the accumulator to oscillate between first and second states, wherein the accumulator draws breathing air into the second variable volume chamber when transitioning from the second state to the first state, and wherein the accumulator forces breathing air from the second variable volume chamber to the respiratory interface when transitioning from the first state to the second state.

The invention discloses an oscillatory flow filtering device. The oscillatory flow filtering device comprises a shell, a filtering assembly and an oscillatory flow fluid generator, the filtering assembly comprises a fixing plate, a flexible filtering layer and a hard supporting structure; the fixing plate is arranged in the shell, a filtering opening is formed in the fixing plate, the hard supporting structure is arranged at the filtering opening, and the flexible filtering layer is arranged on the outer side of the hard supporting structure in a sleeving mode; one side of the shell is provided with an oscillatory flow fluid generator, and the oscillatory flow fluid generator is communicated with the shell and used for driving the flexible filter layer to contract or relax. And the contradiction among the performance, the regeneration efficiency and the cost of the traditional filter in the prior art, such as the dirt containing capacity, the filtering precision and the continuous operation, is solved. The fluid is directly driven by the oscillation device, so that the filter cake layer is automatically updated during operation, and the operation stability and the long-term operation reliability are ensured. The method has universality from low-concentration suspension liquid to medium-concentration suspension liquid. And integration with other functional units is easy to realize a full-automatic production process.

The invention provides a spanwise length prediction method for numerical calculation of cylindrical streaming of oscillatory flow, and belongs to the field of computational fluid mechanics. According to an oscillatory flow incoming flow velocity field, a cylinder diameter and fluid viscosity of a to-be-simulated problem, a two-dimensional oscillatory flow cylinder streaming numerical calculation model is established based on a direct numerical simulation method, and a fully developed two-dimensional periodic base flow is obtained; and further based on a Floquet stability analysis method, establishing a three-dimensional stability analysis model, applying linear perturbation of different wavelengths to the base flow, and obtaining a relation curve of a Floquet multiplier mu and a wavelength lambda by solving a linearized Navier-Stokes equation, thereby determining a characteristic wavelength lambda enabling the mu to be the maximum value, and taking the characteristic wavelength lambda as the spanwise characteristic length of cylindrical streaming of the oscillatory flow under the working condition. According to the method, a theoretical basis is provided for setting of the spanwise length in three-dimensional numerical simulation, the precision and reliability of oscillating flow cylinder streaming numerical simulation are effectively improved, and the method is suitable for hydrodynamic analysis and design of structures such as a floating tunnel in ocean engineering.

The application discloses a pulsating heat pipe heat transfer model and a calculation method based on oscillating flow characteristic number, and belongs to the technical field of heat exchange equipment, and comprises the following steps: establishing a pulsating heat pipe model, determining working medium and evaporation section and condensation section temperature; taking initial amplitude, initial frequency, initial liquid film thickness and initial bullet temperature as assumed parameters, solving liquid bullet temperature distribution through a liquid bullet energy equation; constructing a liquid bullet motion equation based on the initial amplitude and the initial frequency, calculating liquid bullet displacement and combining the initial bullet temperature to calculate bullet pressure; calculating bullet temperature according to bullet pressure and performing iterative correction; updating liquid bullet temperature distribution according to the corrected bullet temperature and calculating liquid film theoretical thickness, and performing iterative correction; based on the oscillating flow Nusselt correlation, the initial amplitude and the initial frequency are iteratively corrected, and the sensible heat and the flow thermal resistance are calculated according to the iteratively converged parameters. The application discloses the correlation between the oscillating flow characteristic number and the heat transfer performance, and provides reliable data support for heat pipe design.

This invention proposes a periodic oscillating flow field simulation device and its usage method, including a water tank and a flow field direction adjustment mechanism. A guide plate is provided in the water tank, and a flow channel is formed between the bottom of the guide plate and the bottom of the water tank. The test piece is placed at the bottom center of the flow channel. The flow field direction adjustment mechanism is set on the left and right sides of the guide plate to form a left water collection cavity and a right water collection cavity. The left and right water collection cavities form a liquid level difference, which changes the water flow direction in the flow channel. This invention has the advantages of simple structure, easy operation, and high flow field simulation accuracy. It can simulate a fixed-frequency oscillating flow field at the bottom of the water.

A mechanical ventilator may include an oscillating flow controller and a respiratory interface fluidly connected to a bi-directional fluid port of the oscillating flow controller. The mechanical ventilator may be connected to a source of pressurized breathing air. Breathing air from the source of pressurized breathing air may drive the oscillating flow controller to periodically change state according to a predetermined cycle emulating a predetermined breathing pattern. The same breathing air may be provided to a user according to the predetermined cycle.

Techniques described herein involve an electronics-free downhole flow sensor. For example, a system can include a receiver positioned at a surface of a wellbore. A flow sensor can be positioned downhole in the wellbore. The flow sensor can include a wire positioned within a flow path of downhole fluid in the wellbore. The wire can oscillate based on flow of the downhole fluid. The flow sensor can also include a variable reluctance sensor that can detect an electrical signal that is generated by oscillation of the wire. The variable reluctance sensor can transmit the electrical signal to the receiver. The receiver may determine a resonant frequency based on the electrical signal and may determine a fluid velocity of the downhole fluid based on the resonant frequency.

This invention provides a hydraulically driven self-excited oscillating nozzle. As a novel device that optimizes water spraying performance by relying on the self-excited oscillation effect of fluid, this nozzle aims to solve the problems of limited spray range and uneven coverage caused by high jet concentration in traditional nozzles. Its core structure integrates a self-excited vibration resonant cavity and an oscillating flow channel. During operation, the pressure pulsation formed by water flowing through the special flow channel couples with the resonant cavity, causing the ejected jet to undergo radial diffusion and pulsation breakup under the action of self-excited oscillation, significantly enhancing the jet's spreading ability. Compared to traditional nozzles, this type of nozzle not only retains the advantages of small atomized particle size, low energy consumption, compact structure, and no need for an external power supply, but also achieves a significant expansion of the spraying range. It provides key equipment support for efficient, water-saving, large-area water spraying technology and has significant practical implications for improving water spraying efficiency and reducing water consumption.

This invention relates to the field of thermoacoustic power generation technology, and provides a turbine power generation system driven by a thermoacoustic engine rectification, comprising: a thermoacoustic engine for converting thermal energy into reciprocating oscillating flow of a working fluid to generate acoustic energy; a rectifier module, with its input end coupled to the output end of the thermoacoustic engine, for rectifying the acoustic energy of the reciprocating oscillating flow into steady-state DC; and a turbine power generation module, with its input end coupled to the output end of the rectifier module, for receiving the steady-state DC and converting the mechanical energy in the steady-state DC into electrical energy through a thermodynamic cycle. This configuration effectively solves the problem that existing thermoacoustic linear generators are limited by power density and amplification capabilities, making it difficult to meet the demands of high-power power generation. It also reduces manufacturing costs. Furthermore, by replacing the compressor in a Brayton cycle power generation system with a thermoacoustic engine, it reduces rotating parts in the compressor, lowers maintenance requirements, improves system reliability, and facilitates higher thermoelectric conversion efficiency and wider heat source adaptability.