scholarly journals Research on the Distribution Rule of Percussion Response Pulse Width in Coin-Tap Test

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Jian Li ◽  
Liping Xu ◽  
Xiaowen Yu ◽  
Jianjun Peng ◽  
Lei Huang
Keyword(s):  
Pulse Width ◽  
Honeycomb Structure ◽  
Test Results ◽  
Distribution Law ◽  
Defect Center ◽  
Tap Test ◽  
Distribution Rule ◽  
Calculation Results ◽  
Physical Laws ◽  
Defective Area

The coin-tap method performs nondestructive testing by measuring the width of the tapping response pulse on the surface of the material. Existing studies have shown that defects in the material will cause the width of the tapping response pulse to increase. However, experiments have confirmed that different detection positions in the defective area will show different values of the width of the tapping response pulse, and the physical laws behind it have not been studied yet. To discuss its physical meaning, a mathematical model of the defective area is established, a method for calculating the width of the tapping response pulse is proposed, and a composite honeycomb structure with preset defects is used for data testing. Both the test results and the calculation results show that the pulse width of the tapping response will decrease with the increase of the defect depth and the deviation of the tapping position from the defect center. The consistency between the calculated results and the experimental results shows that the established defect model and pulse width calculation method can better explain the distribution law of the pulse width of the tapping response in the defective area.

scholarly journals DIAGNOSTIC AN GNOSTIC ANALYSIS OF RANDOM VIBRA SIS OF RANDOM VIBRATION RESUL TION RESULTS IN THE AVIATION GAS TURBINE ENGINES PULSE-WIDTH AUTOMATIC CON TIC CONTROL SY TROL SYSTEMS BASED ON D STEMS BASED ON DYNAMIC GRAPHS AMIC GRAPHS

2019 ◽  
Vol 2019 (2) ◽  
pp. 13-19
Author(s):  
G Tuganov ◽  
C Rakhimov ◽  
E Norkulov
Keyword(s):  
Driving Force ◽  
Pulse Width ◽  
Random Vibration ◽  
Turbine Engines ◽  
Technical Diagnostics ◽  
Gas Turbine Engines ◽  
Dynamic Graphs ◽  
Distribution Law ◽  
Random Probability ◽  
Vibration Parameters

Studies are often conducted to minimize the effect of vibration on equipment and its mechanisms. Since the engine is the main driving force of all technical objects, vibration is one of the factors hindering its operation. With this in mind, this article investigated the random probability distribution of vibration parameters using the laws of mathematical statistical distribution and was found to be compatible with the normal distribution law. At the same time, this study demonstrates that the proposed method of technical diagnostics can be used to assess helicopter engine failures.

scholarly journals Determination of Nearest Emergency Service Office using Haversine Formula Based on Android Platform

2018 ◽  
Vol 5 (2) ◽  
pp. 270-278 ◽  
Author(s):  
M. Basyir ◽  
M. Nasir ◽  
Suryati Suryati ◽  
Widdha Mellyssa
Keyword(s):  
Emergency Service ◽  
Emergency Services ◽  
Message Delivery ◽  
Test Results ◽  
Average Delay ◽  
Accuracy Test ◽  
Calculation Results ◽  
Testing Accuracy ◽  
Selection Of

Emergency Reporting Application is an android-based application that serves to help the community in reporting the emergency condition. This application allows users to choose and contact the emergency services office, without the need to notice their position and phone number. Selection of emergency services office is also automatically selected by the system by taking into account the distance between the complainant and the emergency services office. The selected emergency services office is the nearest emergency service office from the complainant so that the delay in coming assistance can be minimized. Therefore, this proposed application requires a GPS feature to recording, reporting and SMS positioning for message delivery of reports. The distance between the position of the complainant and the position of the emergency service office, in the form of latitude and longitude data, is requested using the Haversine formula taking into account the degree of curvature of the earth. Emergency service offices include police and hospital offices spread over 25 different districts. Furthermore, the reporter's position calculation results were compared with all selected emergency service offices and obtained 1 nearest emergency service office. Calculating the accuracy and delay value of the system will do system testing. Accuracy test results using the method of 100% Haversine and the average delay of the system is 4.5 seconds.

scholarly journals PENGUJIAN PERFORMA REAKTOR DOWNDRAFT BIOMASSA KOTORAN SAPI

POROS ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 121
Author(s):  
Muhammad Ridwan Ridwan ◽  
Noviyanti Nugraha Nugraha
Keyword(s):  
Alternative Energy ◽  
Power Plants ◽  
Gas Content ◽  
Cow Dung ◽  
Test Results ◽  
Discharge Temperature ◽  
Calculation Results ◽  
Chamber Temperature ◽  
Biomass Power Plant ◽  
Biomass Power Plants

Biomass power plants are electricity generators with alternative energy that utilize organicmaterials, in this case cow dung. The cow dung is then processed to produce syngas. Syngas is used as fuelto turn turbines. In previous studies, a cow manure gasification reactor was designed and manufactured.This reactor is part of a biomass power plant system (PLTBm) which is made separately. The power outputtarget of this PLTBm is 370 kW. The purpose of this study was to examine the performance of the downdraftreactor of cow dung biomass, namely discharge, temperature, and analyze the gas content released by thereactor so that the power that can be generated by the reactor can be obtained. The test results obtained acombustion chamber temperature of 580°C and a discharge of 0.285 m3/s. The composition of the outputgas is acetylene 58.16%, hexane 27.66%, butane 6.38%, and methane 7.8%. From the calculation results,the power generated by the reactor is 342 kW.

scholarly journals PENGARUH KEPERCAYAAN DAN ELECTRONIC WORD OF MOUTH (eWOM) TERHADAP PURCHASE INTENTION (Studi Pada Pelajar Kampung Inggris Pare-Kediri)

2019 ◽  
Vol 4 (1) ◽  
pp. 63
Author(s):  
Akhmad Nasir
Keyword(s):  
Purchase Intention ◽  
Word Of Mouth ◽  
Sampling Technique ◽  
Electronic Word Of Mouth ◽  
Test Results ◽  
Simultaneous Test ◽  
Library Studies ◽  
Calculation Results ◽  
English Village

This study aims to find out and analyze the influence of eWOM (Electronic Word Of Mouth) Trust and Purchase Intention on Students in the English village of Pare-Kediri. The population in this study were those who took courses at the Pare-Kediri English village course institute in January-March 2019 which obtained a sample of 100 respondents with accidental sampling technique. Methods of collecting data using questionnaires, observation, interviews, and library studies. The test results partially show that there is a significant and significant effect on the trust variable on Purchase Intention as evidenced by a significant value of 0,000 which is smaller than 0.05 (0,000 <0,05). The partial test results show that there is a significant and significant effect between eWOM variables on Purchase Intention as evidenced by a significant value of 0.005 which is smaller than 0.05 (0.005 <0.05). Based on the calculation results obtained a significant value is 0,000. This shows that the significant value of the test is the trust variable F and eWOM <0.05, which means that the results of this simultaneous test are trust and eWOM has an effect on Purchase Intention. Penelitian ini bertujuan untuk mengetahui dan menganalisis pengaruh Kepercayaan Dan eWOM ( Elektronik Word Of Mouth ) teradap Purchase Intention pada Pelajar di kampung inggris Pare-Kediri. Populasi dalam penelitian ini adalah yang mengambil kursus di lembaga kursus kampung inggris Pare-Kediri pada bulan Januari-Maret 2019 yang  diperoleh sampel sebanyak 96 responden dengan teknik accidental sampling. Metode pengumpulan data menggunakan kuesioner, obsevasi, wawancara, dan Studi kepustakaan. Hasil pengujian secara parsial menunjukan bahwa berpengaruh dan signifikan antara variabel kepercayaan terhadap Purchase Intention yang dibuktikan dengan nilai signifikan sebesar 0,000 dimana lebih kecil dari 0,05 (0,000 < 0,05). Hasil pengujian secara parsial menunjukan bahwa berpengaruh dan signifikan antara variabel eWOM terhadap Purchase Intention yang dibuktikan dengan nilai signifikan sebesar 0,005 dimana lebih kecil dari 0,05 (0,005 < 0,05). Berdasarkan hasil perhitungan diperoleh nilai signifikan adalah 0,000. Hal ini menunjukan bahwa nilai signifikan uji F variabel kepercayaan dan eWOM <0,05 yang berarti hasil dari pengujian simultan ini adalah kepercayaan dan eWOM berpengaruh terhadap Purchase Intention.

Calculation methods of bridge deck for prestressed short rib T-beam bridges

2020 ◽  
pp. 1-13
Author(s):  
Sijia Wang ◽  
Tianlai Yu
Keyword(s):  
Finite Element ◽  
Bridge Deck ◽  
Mechanical Performance ◽  
Test Results ◽  
Analysis Method ◽  
Slab Method ◽  
Element Analysis ◽  
Calculation Results ◽  
Beam Bridge ◽  
T Beam

Because of the low height of the prestressed short rib T-beam bridge and the poor torsion resistance of the main beam, the positive moment in the middle span of the bridge deck will increase correspondingly compared with the normal rib beam bridge. At present, there is little research on the calculation method of the bridge deck of the prestressed short rib T-beam bridge. In this paper, the space finite element method and the continuous one-way slab method are used to calculate the forces on the bridge deck, based on the space finite element method, a finite element elastic supported continuous beam method is proposed to calculate the forces on the bridge deck. By comparing the calculation results of the three methods with the test results, the reasonable calculation method of the bridge deck is studied. The results show that the spatial finite element analysis method can simulate the mechanical performance of the deck of the bridge of the prestressed short rib T-beam bridge well, the stress calculation results are consistent with the test results, and the calculation accuracy is high, which can be used in the actual engineering design; The finite element analysis method of elastic support continuous beam can also simulate the mechanical performance of the deck of the bridge of the prestressed short rib T-beam bridge. The concept of the method is clear, the calculation is convenient, and it is more suitable for the application of engineering design; The calculation results of the continuous one-way slab method are too large to be safe for design.

scholarly journals Condensation of Novec 649 refrigerant in pipe minichannels

2018 ◽  
Vol 70 ◽  
pp. 02002 ◽  
Author(s):  
Tadeusz Bohdal ◽  
Henryk Charun ◽  
Małgorzata Sikora
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Mass Flux ◽  
Flow Structures ◽  
Test Results ◽  
Calculation Results ◽  
Vapour Quality ◽  
Inner Diameter

The paper presents the results of experimental investigation of Novec 649 refrigerant condensation in tube minichannels. This is a low-pressure refrigerant. This investigations are basis for flow structures visualization during condensation in pipe minichannels. The local and the average values of pressure drop (Δp/L) and heat transfer coefficient α in the whole range of the changes of vapour quality (x = 1 ÷ 0) were calculated. On the basis of the obtained test results there was illustrated the influence of the vapour quality x, the mass flux density G and the inner diameter of channel d changes on the studied parameters. These results were compared with the calculation results based on the dependencies of other authors.

scholarly journals Comparative analysis of cycloid pump based on CFD and fluid structure interactions

2020 ◽  
Vol 12 (11) ◽  
pp. 168781402097353
Author(s):  
Wang Yanhua ◽  
Huang Longlong ◽  
Liu Yong ◽  
Xu Jingsong
Keyword(s):  
Model Building ◽  
Contact Point ◽  
Great Influence ◽  
Test Results ◽  
Fluid Structure Interactions ◽  
Fluid Structure ◽  
Mean Values ◽  
Calculation Results ◽  
Different Temperatures ◽  
Set Up

At present, in the aspect of numerical simulation of cycloid pump, most studies focused on CFD (Computational Fluid Dynamics) in analyzing the pump performance under different service conditions (such as speed, temperature, etc.). The characteristics of the pump under FSI (Fluid Solid Interaction) have not been considered yet. By means of the dynamic mesh technique in the rotating domain, the fluid structure coupling interface is set up on a cycloidal pump model building in COMSOL. The simulation results obtained by applying CFD and FSI are improved by experimental verification. The results show that: (1) the average flow rate of FSI simulation is closer to the test results, and the mean values of CFD and FSI pressure are closer to the actual outlet boundary settings; (2) by comparing the velocity and pressure of rotation region of CFD and FSI at different temperatures, it is concluded that the pressure CFD calculated in the region is more than FSI, and the velocity CFD calculated is less than FSI; (3) by comparing the pressure distribution at some contact point of the fluid structure coupling interface, it is concluded that the fluctuation value of the pressure of CFD with time is greater than that of FSI. Through the comparison, it is found that the coupling has a great influence on the calculation results. The FSI analysis of the pump makes the analysis results more real and more conducive to the analysis of the flow field and rotor dynamics characteristics of the pump.

scholarly journals Examination of combined ferry on the dynamic work

2019 ◽  
Vol 265 ◽  
pp. 02008
Author(s):  
Dmitry Tryapkin ◽  
Yuriy Tryapitsin
Keyword(s):  
Dynamic Characteristics ◽  
Dynamic Coefficient ◽  
Test Results ◽  
Dynamic Work ◽  
Calculation Results

The results of the dynamic characteristics experiments and calculation of combined crossing dynamic coefficient are given. The experiments were carried out by temporal automobile load with using measuring rated complex. Agreement of calculation results and test results is obtained.

Design and Fabrication of Novel Electrode-Supported SOFC Having Honeycomb Structure

2008 ◽  
Author(s):  
Toshiaki Yamaguchi ◽  
Toshio Suzuki ◽  
Yoshinobu Fujishiro ◽  
Masanobu Awano ◽  
Sota Shimizu
Keyword(s):  
Numerical Simulation ◽  
Pressure Drop ◽  
Cost Reduction ◽  
Unit Volume ◽  
Honeycomb Structure ◽  
Current Collection ◽  
Fuel Flow ◽  
Space Saving ◽  
Channel Surface ◽  
Calculation Results

We have developed a novel and highly effective electrode-supported SOFC with honeycomb structure for intermediate temperature operation. Honeycomb supported SOFC is known as one of the most compact SOFCs due to the large electrode area per unit volume, which is attractive with regard to space saving and cost reduction. In this study, we summarized the design of channel shape, size and sequence using numerical simulation and the technologies to realize the designed honeycomb SOFC fabrication. The calculation results showed that the wall thickness and the channel size of the honeycomb had to be less than 0.22 mm and more than 0.3 mm, respectively, for the sufficient net channel surface and the acceptable pressure drop. And a cathode-honeycomb supported SOFC can be the more efficient form with the lower current collection resistance, as compared with the anode-supported type. The actually fabricated honeycomb SOFC exhibited a high volumetric power density above 1 W/cm3 at 650 °C under wet H2 fuel flow.

scholarly journals Experimental Investigation on Flexural Behavior of Granite Stone Slabs with Near Surface Mounted CFRP Bars and Screw-Thread Steels

2018 ◽  
Vol 2018 ◽  
pp. 1-30
Author(s):  
Xiaopeng Gao ◽  
Zhongfan Chen ◽  
Xiaomeng Ding ◽  
Erxiang Dong
Keyword(s):  
Failure Load ◽  
Ductile Failure ◽  
Flexural Behavior ◽  
Screw Thread ◽  
Test Results ◽  
Cracking Behavior ◽  
Near Surface ◽  
Four Point Bending ◽  
Calculation Results ◽  
Near Surface Mounted

An experimental study that investigates the behavior of stone slabs strengthened in fixure with near surface mounted (NSM) technique using screw-thread steels and carbon fiber-reinforced polymer (CFRP) bars is presented. A total of ten full-scale stone slabs were tested under a four-point bending loading to investigate the effect of groove dimension, reinforcement ratios, and reinforcement materials on the flexural performance of stone slabs. The test results included failure characteristics, yield and ultimate capacities, deflection of midspan, and cracking behavior of stone slabs. The test results indicate that with the increase of groove height and groove width, cracking load and middeflection decrease by 6.4%–14.18%; however, failure load and middeflection increase by 4.7%–41.2%. Cracking load, failure load, and failure displacement of stone slabs adopting NSM screw-thread steels increased by 10.9%, 167%, and 617%, respectively, under the maximum reinforcement ratios of 0.629% over the control slab without NSM bars. Meanwhile, with the increase of reinforcement ratios, the failure mode transforms from brittle failure to ductile failure. The calculation results of strength are in agreement with the experimental results. Finally, it can be concluded that NSM CFRP bars are more effective than NSM screw-thread steels to improve flexural capacity with the same reinforcement ratios.

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