A Test System for Pressure Pulsation and Hydrodynamic Noise in Centrifugal Pump Based on Virtual Instrument Technology

2011 ◽  
Author(s):  
Yin Luo ◽  
Shouqi Yuan ◽  
Yue Tang ◽  
Jianping Yuan ◽  
Jinfeng Zhang
Keyword(s):  
Centrifugal Pump ◽  
Virtual Instrument ◽  
Pressure Pulsation ◽  
Test System ◽  
Real Time System ◽  
Pump System ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Hydrodynamic Noise ◽  
Set Up

A system based on virtual instrument was set up to test and analyze the pressure pulsation and hydrodynamic noise in centrifugal pump. It has adjustable sampling time length and frequency which can avoid the disadvantages of data loss and redundancy caused by fixed sampling parameters. A signal preprocessing toolkit compiled by LabVIEW was set up, which can anti the aliasing of the signal by use of the low pass filter, decrease the noise in the concerned frequency by the wavelet de-noising and efficiently reduce the error caused by test system. Meanwhile, the data analysis toolkits in this system not only include signal power spectrum and octave for obtaining the frequency characteristic, but also include correlation analysis between the measured waveforms and wavelet analysis for detecting the signature of the signal. All of the toolkits could be used as an automatic real-time system. The feasibility of this system has already been evaluated in a centrifugal pump system, and it is testified that this system can realize and analyze the pressure pulsation and inner hydrodynamic noise automatically.

Test System for Pressure Pulsation in Centrifugal Pump Based on Virtual Instrument Technology

2011 ◽  
Vol 346 ◽  
pp. 724-730
Author(s):  
Yin Luo ◽  
Yue Tang ◽  
Shou Qi Yuan ◽  
Hui Wang
Keyword(s):  
Centrifugal Pump ◽  
Frequency Characteristic ◽  
Virtual Instrument ◽  
Pressure Pulsation ◽  
Test System ◽  
Real Time System ◽  
Pump System ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Set Up

A system based on virtual instrument was set up to test and analyze the pressure pulsation in centrifugal pump. It had adjustable sampling time length and frequency which can avoid the disadvantages of data loss and redundancy caused by fixed sampling parameters. A signal preprocessing toolkit compiled by LabVIEW was set up, which can anti the aliasing of the signal by use of the low pass filter, decrease the noise in the concerned frequency by the wavelet de-noising and efficiently reduce the error caused by test system. Meanwhile, the signal’s frequency characteristic could be analyzed in this system automatic, and the detail of the frequency characteristic could be captured by zoom FFT. All of the toolkits could be used as an automatic real-time system. The feasibility of this system has already been evaluated in a centrifugal pump system, and it is testified that this system can realize and analyze the pressure pulsation automatically.

The Application Study of Accumulator Used in Hydraulic System of 20MN Fast Forging Machine

2011 ◽  
Vol 80-81 ◽  
pp. 870-874 ◽  
Author(s):  
Min Qiang Dai ◽  
Sheng Dun Zhao ◽  
Xiao Mei Yuan
Keyword(s):  
Energy Conservation ◽  
Hydraulic System ◽  
Pressure Pulsation ◽  
Test System ◽  
Hydraulic Shock ◽  
Application Study ◽  
Calculation Results ◽  
Set Up ◽  
Forging Press ◽  
Made In

Based on the description of 20MN fast forging press hydraulic system, the paper analyzed the possibility of energy conservation which the accumulator made in the fast forging machine system. When accumulator was used in fast forging machine, then analyzed the calculation results, and the energy conservation program of fast forging machine energy accumulator was evaluated briefly. The test system was set up on 20MN fast forging machine, and the paper researched the application of accumulator in fast forging press hydraulic system on absorbing hydraulic shock and eliminating pressure pulsation.

scholarly journals Impact of the Incremental Analysis Updates on a Real-Time System of the North Atlantic Ocean

2008 ◽  
Vol 25 (11) ◽  
pp. 2055-2073 ◽  
Author(s):  
M. Benkiran ◽  
E. Greiner
Keyword(s):  
Real Time ◽  
North Atlantic ◽  
Weather Forecasting ◽  
Incremental Analysis ◽  
Real Time System ◽  
Pass Filter ◽  
Low Pass Filter ◽  
The North ◽  
The North Atlantic ◽  
The Impact

Abstract Incremental analysis updates (IAUs) are a procedure by which analysis increments can be incorporated into a model hindcast and forecast in a smooth manner. It is similar to nudging but has a better response, particularly in regions of missing data. The IAU procedure was popular in the late 1990s in weather forecasting centers, because it acts as a low-pass filter. The impact of the IAU is examined in the context of a real-time, eddy-permitting ocean forecasting system in the North Atlantic from Mercator Océan. Forecast scores and ocean physics are compared for the following three companion runs: a forced mode, a sequential analysis, and IAU. These comparisons confirm that the IAU is beneficial because it removes spinup effects such as spurious waves and tropical convective cells. Forecast scores are also slightly improved. In addition, contrary to the weather forecasting case where the model and data are fairly unbiased, the IAU has the advantage of correcting the systematic biases in the ocean data assimilation system.

Attenuation of Gas Pulsation in a Reciprocating Compressor Piping System by Using a Volume-Choke-Volume Filter

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Boxiang Liu ◽  
Jianmei Feng ◽  
Zhongzhen Wang ◽  
Xueyuan Peng
Keyword(s):  
Characteristic Frequency ◽  
Pressure Pulsation ◽  
Natural Frequencies ◽  
Three Dimensional ◽  
Piping System ◽  
Reciprocating Compressor ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Response Characteristics ◽  
Low Pass

This paper presents an investigation of the use of a volume-choke-volume low-pass filter to achieve gas pulsation attenuation in a reciprocating compressor piping system, with a focus on its frequency response characteristics and influence on the actual attenuation effects. A three-dimensional acoustic model of the gas pulsation was established for a compressor discharge piping system with and without the volume-choke-volume filter, based on which the gas column natural frequencies of the piping system and the pressure wave profiles were predicted by means of the finite element method. The model was validated by comparing the predicted results with the experimental data. The results showed that the characteristic frequency of the filter was sensitive to both diameter and length of the choke but independent of the parameters of the piping beyond the filter. It is worth noting that the characteristic frequency of the filter constituted one order of the gas column natural frequencies of the piping system with the filter. The pressure pulsation levels in the piping system downstream of the filter could be significantly attenuated especially for the pulsation components at frequencies above the filter’s characteristic frequency. The measured peak-to-peak pressure pulsation at the outlet of the filter was approximately 61.7% lower than that of the surge bottle with the same volume.

scholarly journals Adaptive anti-disturbance control for a class of unknown pure feedback switched nonlinear systems

2021 ◽  
Author(s):  
Longsheng Chen
Keyword(s):  
Nonlinear Systems ◽  
Design Method ◽  
Tracking Error ◽  
Average Dwell Time ◽  
Switched Nonlinear Systems ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Control Scheme ◽  
Low Pass ◽  
Set Up

Abstract In this study, an adaptive anti-disturbance control scheme is investigated for a class of unknown pure feedback switched nonlinear systems subjected to immeasurable states and external disturbances. Radial basis function neural networks (RBFNNs) are employed to identify the switched unknown nonlinearities, and a Butterworth low-pass filter is adopted to remove the algebraic loop problem. Subsequently, a novel switched neural state observer and a novel switched disturbance are presented via the coupled design method to estimate the immeasurable states and compounded disturbances. Then, an improved adaptive control strategy for the studied problem is designed with the help of a filtering method to eliminate the “explosion of complexity” problem, and certain compensating signals are set up to compensate for the filter errors, where switched updated laws are constructed to lessen the conservativeness caused by adoption of a common updated law for all subsystems. By utilizing the Lyapunov stability theorem, the developed control scheme can guarantee that all signals in the closed-loop system are bounded under a class of switching signals with the average dwell time (ADT), while the tracking error can converge to a small neighbourhood of origin. Finally, simulation results are provided to demonstrate the effectiveness of the presented approach.

scholarly journals Convolution Integral: How a Graphical Type of Solution Can Help Minimize Misconceptions

2021 ◽  
Vol 3 (2) ◽  
pp. 103
Author(s):  
Hendra J. Tarigan
Keyword(s):  
Impulse Response ◽  
Physical System ◽  
Convolution Integral ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Convolution Integrals ◽  
Low Pass ◽  
Simulation And Experiment ◽  
Rc Circuit ◽  
Set Up

A physical system, Low Pass Filter (LPF) RC Circuit, which serves as an impulse response and a square wave input signal are utilized to derive the continuous time convolution (convolution integrals). How to set up the limits of integration correctly and how the excitation source convolves with the impulse response are explained using a graphical type of solution. This in turn, help minimize the students’ misconceptions about the convolution integral. Further, the effect of varying the circuit elements on the shape of the convolution output plot is presented allowing students to see the connection between a convolution integral and a physical system. PSpice simulation and experiment results are incorporated and are compared with those of the analytical solution associated with the convolution integral.

scholarly journals Hydrodynamic and Hydrographic Modeling of Istanbul Strait

2019 ◽  
Author(s):  
Mehmet Melih Koşucu ◽  
Mehmet Cüneyd Demirel ◽  
V.S. Ozgur Kirca ◽  
Mehmet Özger
Keyword(s):  
Mixing Layer ◽  
Open Boundary ◽  
Roughness Coefficient ◽  
Model Parameters ◽  
Temperature Profiles ◽  
Open Boundary Conditions ◽  
Pass Filter ◽  
Low Pass Filter ◽  
The North ◽  
Set Up

The aim of this study is to model hydrodynamic processes of the Istanbul Strait with its stratified flow characteristic and calibrate the most important parameters using local and global search algorithms. For that two open boundary conditions are defined, which are in the North and South part of the Strait. Observed bathymetric, hydrographic, meteorological and water level data are used to set up the Delft3D-FLOW model. First, the sensitivities of model parameters on the numerical model outputs are assessed using PEST toolbox. Then, the model is calibrated based on the objective functions focusing on the flowrates of upper and lower layers. The salinity and temperature profiles of the Strait are only used for model validation. The results show that the calibrated model outputs of Istanbul Strait are reliable and consistent with the in-situ measurements. The sensitivity analysis reveals that the Spatial Low-Pass Filter Coefficient, Horizontal Eddy Viscosity, Prandtl-Schmidt Number, Slope in log-log Spectrum and Manning Roughness Coefficient are most sensitive parameters affecting flowrate performance of the model. The agreement between observed salinity profiles and simulated model outputs is promising whereas the match between observed and simulated temperature profiles is weak showing that the model can be improved particularly for simulating the mixing layer.

Design of the Transpire Freight Impact Test System Based on ASTM D6537

2011 ◽  
Vol 128-129 ◽  
pp. 1417-1420
Author(s):  
Zi Fen He ◽  
Zhao Lin Zhan ◽  
Yin Hui Zhang
Keyword(s):  
Test Object ◽  
Impact Test ◽  
Test System ◽  
Standard Test ◽  
Drop Height ◽  
Laptop Computer ◽  
Velocity Change ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

In this paper, we develop a transpire freight impact test system based on ASTM D6537 standard. Test object is the transportation packaging of the laptop computer in the process of drop impact test. Data acquisition are handled using low-pass filter via Matlab software, which calculated four test indicators that consist of peak acceleration, the filtered acceleration, velocity change and pulse duration. We use several drop ways, which the drop height is 40cm and 70cm, respectively. Experiments show that the test object can protect the product safety when drop height is 70cm, but the box will be broken.

Design and Application of the Testing System for a New Pipe Pressure Sensor

2014 ◽  
Vol 904 ◽  
pp. 395-398
Author(s):  
Xiao Ming Zhang ◽  
Yi Yuan ◽  
Jian Min Liu
Keyword(s):  
Data Acquisition ◽  
Pressure Sensor ◽  
Dynamic Pressure ◽  
Current Source ◽  
Test System ◽  
Constant Current ◽  
Measured Signal ◽  
Constant Current Source ◽  
Pass Filter ◽  
Low Pass Filter

The new pipe pressure sensor is a clamp-on ICP (Integrated Circuit Piezoelectric) type dynamic pressure sensor, mainly for the clamp-on pressure testing of high pressure fuel pipe. In testing, the vibration of the fuel injection pumps and diesel engine will disturb the clamp-on pressure signals, resulting in one of the measured signal to noise ratio is low, the second is the test system, in particular the signal transmission have a significant impact. In response to these problems, designed a PCI data acquisition card building-in constant-current source and special low pass filter, and developed the corresponding data acquisition software based on C++ Builder. The bench and real vehicle testing show: the test system can better fit with the new type pressure sensor to obtain accurate clamp-on pressure signals.

scholarly journals Hydrodynamic and Hydrographic Modeling of Istanbul Strait

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 710 ◽  
Author(s):  
Mehmet Koşucu ◽  
Mehmet Demirel ◽  
V.S. Kirca ◽  
Mehmet Özger
Keyword(s):  
Mixing Layer ◽  
Flow Characteristics ◽  
Open Boundary ◽  
Roughness Coefficient ◽  
Model Parameters ◽  
Temperature Profiles ◽  
Open Boundary Conditions ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Set Up

The aim of this study is to model the hydrodynamic processes of the Istanbul Strait with its stratified flow characteristics, and calibrate the most important parameters using local and global search algorithms. For that, two open boundary conditions are defined, which are in the northern and southern parts of the Strait. Observed bathymetric, hydrographic, meteorological, and water-level data are used to set up the Delft3D-FLOW model. First, the sensitivities of the model parameters on the numerical model outputs are assessed using Parameter EStimation Tool (PEST) toolbox. Then, the model is calibrated based on the objective functions, focusing on the flow rates of the upper and lower layers. The salinity and temperature profiles of the strait are only used for model validation. The results show that the calibrated model outputs of the Istanbul Strait are reliable and consistent with the in situ measurements. The sensitivity analysis reveals that the spatial low-pass filter coefficient, horizontal eddy viscosity, Prandtl–Schmidt number, slope in log–log spectrum, and Manning roughness coefficient are most sensitive parameters affecting the flow rate performance of the model. The agreement between observed salinity profiles and simulated model outputs is promising, whereas the match between observed and simulated temperature profiles is weak, showing that the model can be improved, particularly for simulating the mixing layer.

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