scholarly journals Study on Characteristics of the Vibration and Noise of High-Power Scroll Compressor

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Chuang Wang ◽  
Zhen Wang ◽  
Weiguo Yan ◽  
Hongkun Li ◽  
Chunli Yang
Keyword(s):  
Prediction Model ◽  
High Power ◽  
Standardized Test ◽  
Acoustic Radiation ◽  
Rapid Development ◽  
Dynamic Performance ◽  
Low Noise ◽  
Scroll Compressor ◽  
Vibration Displacement ◽  
Radiated Noise

With the rapid development of a high-power scroll compressor (HSC), the dynamic performance of a scroll compressor has an important impact on the vibration and noise of the whole compressor. So, the dynamic characteristics and structural acoustic radiation characteristics of HSC under dynamic excitation are studied by simulation and experiment in this paper. Firstly, the dynamic simulation model of HSC is established to analyze the time-domain and frequency-domain characteristics of bearing excitation and upper support excitation. At the same time, the finite element models of housing, upper support, and lower support are constructed to analyze the transient dynamic response of housing under the excitation source. Based on the vibration displacement of the housing surface, the prediction model of the housing radiated noise is also established, and then the radiated noise of the housing surface and the noise spectrum of the standardized test points are analyzed. Finally, the accuracy of the prediction model is verified by acoustic experiments. The experimental results show that the vibration and radiation noise of the housing can be accurately predicted by reasonable modeling to calculate the gas force and approximate the actual gas load. The vibration of the housing coupling system is the main source of the vibration characteristics of the HSC. The conclusions of the study can provide a reference for the low noise design of the HSC.

Dynamic Performance of High-Speed Electric Multiple Unit within Multi-Body System Simulation

2019 ◽  
Vol 12 (4) ◽  
pp. 339-349
Author(s):  
Junguo Wang ◽  
Daoping Gong ◽  
Rui Sun ◽  
Yongxiang Zhao
Keyword(s):  
High Speed ◽  
Rapid Development ◽  
Dynamic Performance ◽  
Body System ◽  
High Speed Railway ◽  
Evaluation Indexes ◽  
Actual Operation ◽  
Multiple Unit ◽  
The Stability ◽  
Multi Body

Background: With the rapid development of the high-speed railway, the dynamic performance such as running stability and safety of the high-speed train is increasingly important. This paper focuses on the dynamic performance of high-speed Electric Multiple Unit (EMU), especially the dynamic characteristics of the bogie frame and car body. Various patents have been discussed in this article. Objective: To develop the Multi-Body System (MBS) model of EMU, verify whether the dynamic performance meets the actual operation requirements, and provide some useful information for dynamics and structural design of the proposed EMU. Methods: According to the technical characteristics of a typical EMU, a MBS model is established via SIMPACK, and the measured data of China high-speed railway is taken as the excitation of track random irregularity. To test the dynamic performance of the EMU, including the stability and safety, some evaluation indexes such as wheel-axle lateral forces, wheel-axle lateral vertical forces, derailment coefficients and wheel unloading rates are also calculated and analyzed in detail. Results: The MBS model of EMU has better dynamic performance especially curving performance, and some evaluation indexes of the stability and safety have also reached China’s high-speed railway standards. Conclusion: The effectiveness of the proposed MBS model is verified, and the dynamic performance of the MBS model can meet the design requirements of high-speed EMU.

High power and very low noise operation at 1.3 and 1.5 μm with quantum dot and quantum dash Fabry-Perot lasers for microwave links

2006 ◽  
Author(s):  
Patrick Resneau ◽  
Michel Calligaro ◽  
Michel Krakowski ◽  
Huiyun Liu ◽  
Mark Hopkinson ◽  
...  
Keyword(s):  
Quantum Dot ◽  
High Power ◽  
Low Noise ◽  
Fabry Perot ◽  
Quantum Dash

scholarly journals Prediction Model of Football World Cup Championship Based on Machine Learning and Mobile Algorithm

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yanyang Bai ◽  
Xuesheng Zhang
Keyword(s):  
Machine Learning ◽  
Prediction Model ◽  
Clustering Algorithm ◽  
Technological Development ◽  
Rapid Development ◽  
Evidence Theory ◽  
Predictive Analysis ◽  
Learning Technology ◽  
World Cup ◽  
Python Programming

With the technological development and change of the times in the current era, with the rapid development of science and technology and information technology, there is a gradual replacement in the traditional way of cognition. Effective data analysis is of great help to all societies, thereby drive the development of better interests. How to expand the development of the overall information resources in the process of utilization, establish a mathematical analysis–oriented evidence theory system model, improve the effective utilization of the machine, and achieve the goal of comprehensively predicting the target behavior? The main goal of this article is to use machine learning technology; this article defines the main prediction model by python programming language, analyzes and forecasts the data of previous World Cup, and establishes the analysis and prediction model of football field by K-mean and DPC clustering algorithm. Python programming is used to implement the algorithm. The data of the previous World Cup football matches are selected, and the built model is used for the predictive analysis on the Python platform; the calculation method based on the DPC-K-means algorithm is used to determine the accuracy and probability of the variables through the calculation results, which develops results in specific competitions. Research shows how the machine wins and learns the efficiency of the production process, and the machine learning process, the reliability, and accuracy of the prediction results are improved by more than 55%, which proves that mobile algorithm technology has a high level of predictive analysis on the World Cup football stadium.

Dirac nodal surface semimetallic carbon based structure as a universal anode material for metal-ion batteries with high performance

2021 ◽  
Author(s):  
Shouren Zhang ◽  
Huili Liu ◽  
Yadan Zhang ◽  
Shuaiwei Wang ◽  
Baocheng Yang
Keyword(s):  
Anode Material ◽  
High Power ◽  
Metal Ion ◽  
High Performance ◽  
Rapid Development ◽  
Electronic Devices ◽  
Storage Battery ◽  
Nodal Surface ◽  
Power Storage ◽  
Carbon Based

The rapid development of electronic devices require the high power storage battery. However, the reported 3D carbon based materials are semiconductor or metal and used for Li- or Na-ion battery...

Study on high power microwave nonlinear effects and degradation characteristics of C-band low noise amplifier

2022 ◽  
Vol 128 ◽  
pp. 114427
Author(s):  
Li Fuxing ◽  
Chai Changchun ◽  
Wu Han ◽  
Wang Lei ◽  
Liang Qishuai ◽  
...  
Keyword(s):  
High Power ◽  
Nonlinear Effects ◽  
Low Noise ◽  
Low Noise Amplifier ◽  
High Power Microwave ◽  
Noise Amplifier ◽  
Power Microwave

Progress on High-Power Low-Noise Continuous-Wave Single-Frequency All-Solid-State Lasers

2021 ◽  
Vol 48 (5) ◽  
pp. 0501002
Author(s):  
张宽收 Zhang Kuanshou ◽  
卢华东 Lu Huadong ◽  
李渊骥 Li Yuanji ◽  
冯晋霞 Feng Jinxia
Keyword(s):  
Solid State ◽  
High Power ◽  
Continuous Wave ◽  
Low Noise ◽  
Single Frequency ◽  
Solid State Lasers

Software Defect Prediction Using Hybrid Distribution Base Balance Instance Selection and Radial Basis Function Classifier

2019 ◽  
Vol 8 (3) ◽  
pp. 53-75 ◽  
Author(s):  
Mrutyunjaya Panda
Keyword(s):  
Prediction Model ◽  
Radial Basis Function ◽  
Basis Function ◽  
Rapid Development ◽  
Defect Prediction ◽  
Instance Selection ◽  
Software Defect Prediction ◽  
Software Defect ◽  
Radial Basis ◽  
Base Balance

Software is an important part of human life and with the rapid development of software engineering the demands for software to be reliable with low defects is increasingly pressing. The building of a software defect prediction model is proposed in this article by using various software metrics with publicly available historical software defect datasets collected from several projects. Such a prediction model can enable the software engineers to take proactive actions in enhancing software quality from the early stages of the software development cycle. This article introduces a hybrid classification method (DBBRBF) by combining distribution base balance (DBB) based instance selection and radial basis function (RBF) neural network classifier to obtain the best prediction compared to the existing research. The experimental results with post-hoc statistical significance tests shows the effectiveness of the proposed approach.

scholarly journals Suspending force modeling based on nonlinear acoustics and high-speed running experiments for an ultrasonic journal bearing

2020 ◽  
Vol 12 (7) ◽  
pp. 168781402094047
Author(s):  
He Li ◽  
Yu Wang ◽  
Deen Bai ◽  
Fuyan Lyu ◽  
Kuidong Gao ◽  
...  
Keyword(s):  
Lead Zirconate Titanate ◽  
Smart Materials ◽  
High Speed ◽  
Acoustic Radiation ◽  
Dynamic Performance ◽  
Force Model ◽  
Trajectory Data ◽  
Running Performance ◽  
High Speeds ◽  
Radiation Theory

As a kind of promising noncontact bearings, ultrasonic bearings actuated by smart materials such as lead zirconate titanate ceramics show a good application prospect in high-speed machines and precision-measuring devices. The suspending force is one of the most important parameters that play a dominated role on the bearing’s static and dynamic performance. A suspending force model based on acoustic radiation theory for cylindrical object near sound source is built to predict the radial carrying capacity of an ultrasonic bearing actuated by three piezoelectric transducers. To validate the model, an ultrasonic bearing prototype is developed and a testing system is established. For observing the bearing’s dynamic running performance at high speeds, the bearing’s running experiment is carried out and the rotor center’s trajectory data and frequency spectrum are acquired to analyze the bearing’s dynamic characteristics at high speeds. The suspending force model and running performance experiments will contribute to the design, detection, and test of this type of bearings.

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