7 results about "Pressure amplitude" patented technology

The invention discloses a ring main unit emergency pressure relief automatic triggering method and system linked with air pressure monitoring, and relates to the technical field of ring main units, and the method comprises the following steps: collecting a multi-point air pressure time sequence at the moment of an arc fault of a ring main unit, carrying out the phase difference analysis, and generating a pressure phase distribution diagram; identifying a phase reversal interval based on the phase distribution, and forming a shock wave cancellation risk time sequence result; carrying out superposition reconstruction on the multi-point pressure amplitudes to obtain a spatial superposition pressure evolution diagram; and constructing a continuous risk accumulation curve, and implementing pre-trigger control according to the continuous risk accumulation curve, so that pressure relief is started before shock waves are superposed again. According to the method, through multi-point air pressure phase analysis and spatial superposition reconstruction, shock wave cancellation interference is eliminated, a continuous risk accumulation curve is constructed, and emergency pressure relief trigger delay of the ring main unit is avoided; and front triggering is realized based on a risk accumulation curve, so that pressure relief is started before shock waves are superposed again, the compression peak value of the shell is reduced, and the safety of the ring main unit under an arc fault is improved.

The present application relates to the technical field of structural response simulation, in particular to a ship container wave pressure intensity simulation method and system, in the present application, based on Fourier transform, frequency value, direction angle, energy coefficient, pressure amplitude and phase quantity are composed into a unified frequency domain vector, and the surface element pressure history is reconstructed by time step by time, so that the wave load is uniformly distributed in the spectrum domain phase, the frequency component phase superposition and the speed and heading offset are synchronously transmitted to each time point, the surface element pressure history and the sea state spectrum parameters are one-to-one corresponding, through the penalty function method, the displacement difference value and the allowable gap limit value are read at the node layer, the penalty coefficient is selected according to the constraint type to generate the penalty quantity, and the penalty quantity is superimposed to the node pressure record with the time step, the supporting, limiting and allowable movement state is quantified as the penalty term and is updated with the iteration increment, the constraint strength is uniformly controlled by the penalty coefficient grade table, and the working condition switching can reuse the grid and material input by replacing the matrix and penalty coefficient library.

The application discloses a kind of traceable pressure sensor dynamic response calibration method based on absorption spectrum reference pressure input, in shock tube is driven section tail end wall position arrangement to be calibrated pressure sensor, and set optical measurement window in reflected shock action area, synchronous acquisition pressure sensor output signal and absorption spectrum signal;Absorption spectrum signal is preprocessed and spectral line fitting, calculate the gas temperature and collision broadening coefficient after reflected shock wave, and reference pressure amplitude P5 after reflected shock wave is obtained accordingly;Pressure amplitude P1 before incident shock wave is measured using pressure gauge after metrological calibration;According to P1, P5 and pressure mutation time t0 Reference pressure step input signal based on Heaviside step function is constructed;Reference pressure step input signal and pressure sensor output signal are processed, and the ratio of the spectral amplitude of the two is used as the sensitivity of the pressure sensor at the corresponding frequency;Error source in the process of calculating reference pressure amplitude, pressure mutation time and sensitivity is evaluated and calculated, and the sensitivity calibration result of pressure sensor is obtained.The application can obtain the sensitivity characteristics and its uncertainty of pressure sensor.

The invention provides a high-speed train tunnel exit micro-pressure wave sound source extraction method and system, and relates to the technical field of railway tunnels, and the method comprises the steps: obtaining the time domain data of micro-pressure waves at different positions of a tunnel exit based on numerical simulation when a train enters the tunnel; setting a plurality of time windows with different lengths based on the pressure amplitude of the micro-pressure wave and a preset energy ratio; in different time windows, pulsating pressure time sequences of the tunnel exit area are collected; mapping the pulsating pressure time sequences of different time windows into an acoustic grid, calculating a far-field sound pressure level, and extracting corresponding acoustic parameters; establishing an acoustic parameter-sound pressure level response curve under different time windows, and comparing the acoustic parameter-sound pressure level response curve with current vehicle experiment data to obtain an optimal time window; and performing micro-pressure wave sound source extraction based on the optimal time window. By optimizing the time window, insufficient energy extraction or sound source averaging is avoided, the contribution of the main pulse is enhanced, and the accuracy of a noise prediction result is improved.

The uniqueness of the present invention is the development of methods for determining the source localization of transient pressure events, such as blast and sound waves originating from explosions, or other pressure sources, with the preferred embodiment using the illustrated example of a multi-sensor wearable device (MSWD), but any multi-sensor wearable device may be used. This device combines pressure transducers, inertial sensors, and navigational sensors to identify the direction of a pressure source. The invention employs diverse techniques—pressure time-based, pressure amplitude-based, inertial amplitude-based, and / or machine learning—to enhance accuracy. The calculated source location can be used to determine a sensors orientation to the source to estimate a reflected and / or incident pressure. The directional analysis is vital for assessing the impact of pressure waves on surfaces, improving injury assessment, and enhancing safety evaluations as the direction of the blast wave may have different effects on injury outcomes.

The application provides a kind of global regulation high-speed railway tunnel, buffer structure design method, comprising: at the tunnel entrance, the rising time of initial compression wave is extended by buffer structure, so that the pressure rise is divided into two stages, and the pressure gradient amplitude is reduced;Pressure chamber is arranged in the tunnel, so that the compression wave oscillates in the pressure chamber several times, dissipates the energy of pressure wave to relieve the pressure wave and the pressure gradient amplitude;At the same time, local suction method can also be used on the inner wall of the tunnel to further reduce the intensity of the initial compression wave;At the tunnel exit, increase the buffer structure porosity, guide the airflow through the hole to dissipate energy outside, further relieve the micro-pressure wave amplitude at the tunnel exit.The application realizes effective relief of the alternating pressure amplitude in the tunnel and the micro-pressure wave at the tunnel exit by step-by-step energy dissipation at the tunnel entrance-tunnel-tunnel exit, meets the aerodynamic requirements of train rapid passing through the tunnel under multiple operating conditions, and at the same time can meet the demand of two-way driving.

The invention relates to the technical field of structural response simulation, in particular to a ship container wave pressure intensity simulation method and system.According to the ship container wave pressure intensity simulation method and system, a frequency value, a direction angle, an energy coefficient, a pressure amplitude and a phase quantity form a unified frequency domain vector based on Fourier transform, and a surface element pressure history is reconstructed moment by moment according to a time step length; wave loads are distributed in a spectral domain phase consistent mode, frequency component phase superposition and navigational speed and course deviation are synchronously transmitted to all time points, surface element pressure courses correspond to sea condition spectrum parameters one by one, a displacement difference value and a permissible gap limit value are read on a node layer through a penalty function method, and the sea condition spectrum parameters are obtained; penalty coefficients are selected according to constraint types to generate penalty quantities, the penalty quantities are superposed to node pressure records along with time steps, supporting, limiting and allowable movement states are quantified into penalty terms and are updated along with iteration increments, constraint strength is uniformly controlled by a penalty coefficient grade table, and grids and material input can be reused only by replacing a matrix and a penalty coefficient library during working condition switching.