Dynamics Characteristic Analysis of Deliberate Mistuned Bladed-Disk System in Compressor Based on CMS Mothod

2011 ◽  
Vol 305 ◽  
pp. 192-197 ◽  
Author(s):  
Hui Qun Yuan ◽  
Liang Zhang
Keyword(s):  
Dynamic Test ◽  
Frequency Difference ◽  
Costal Margin ◽  
Test Results ◽  
Characteristic Analysis ◽  
Disk System ◽  
Rotating Speed ◽  
Bladed Disk ◽  
Dynamics Characteristic ◽  
Better Than

In this paper first,a method combining dichotomy and finite element is presented which identify elastic modulus parameters of mistuned bladed based on the test data of blade static frequency and simulation blade deliberate mistuned by change elastic modulus.Then, dynamic characteristics of deliberate mistuned 10Hz and 41Hz bladed-disk system were analyzed in work rotating speed based on CMS mothod, respectively. The exciting force of airflow exert on costal margin of blade tip.According to dynamic test results,the incentive order is 4. The analysis results show that along with the mistuning frequency difference increases,the largest amplitude of blade is becoming smaller(except tuned system) , and scheme of large frequency difference 41Hz deliberate mistuned (scheme Ⅱ) better than scheme of small frequency difference 10Hz deliberate mistuned (scheme Ⅰ) for vibration reduction of bladed-disk system in work rotating speed for 11300r/min. The analysis results are consistent with the dynamic test results.

Dynamics Characteristic Analysis of Deliberate Mistuned Bladed-Disk System in Compressor Based on Substructure Method

2011 ◽  
Vol 141 ◽  
pp. 129-133 ◽  
Author(s):  
Hui Qun Yuan ◽  
Liang Zhang ◽  
Lin Song
Keyword(s):  
Elastic Modulus ◽  
Dynamic Test ◽  
Frequency Difference ◽  
Test Results ◽  
Characteristic Analysis ◽  
Disk System ◽  
Substructure Method ◽  
Bladed Disk ◽  
Dynamics Characteristic ◽  
Large Frequency

In this paper, based on the test data of blade static frequency and simulating blade deliberate mistuned by changing elastic modulus, a method combining dichotomy and finite element is presented which can identify elastic modulus parameters of mistuned blades. Then, when value of the frequency difference is 5Hz and 41Hz, dynamic characteristics of deliberate mistuned bladed-disk system are investigated separately under operating speed, on the basis of substructure method. Apply the exciting force of airflow on the fronts of blades tip. According to dynamic test results, it takes 4 as the excitation order. The analysis results show that with the mistuned frequency difference increasing, the largest amplitude of blade will decrease gradually. The deliberate mistuned scheme of large frequency difference as scheme Ⅱ is more effective than the small one as schemeⅠto reduce the vibration of bladed disk system under working speed of 11300r/min. The analysis results are consistent with the dynamic test ones.

scholarly journals RANCANG BANGUN SISTEM REM MOBIL LISTRIK FUSENA

2019 ◽  
Vol 18 (3) ◽  
pp. 243-248
Author(s):  
Fauzan Ilham Maulana ◽  
Noorsakti Wahyudi ◽  
Indah Puspitasari
Keyword(s):  
Dynamic Test ◽  
Brake System ◽  
Test Results ◽  
Static Testing ◽  
Hydraulic Brake ◽  
Electric Car ◽  
System Use ◽  
Braking Distance ◽  
Materials Used ◽  
Better Than

The brake system is a device to slow down or stop the movement of the wheel automatically so that the vehicle will move slowly. This completeness in the vehicle is very important and vital because it functions as a safety for life in driving. In the process of making the Electric Car Fusena brake system has steps in the process, consists of size planning, materials used, designs realized, manufacturing brake system supporting components, assembly, installation and testing of brake systems. The Fusena Electric Car brake system use a disc-type hydraulic brake system with one brake master that can work simultaneous with dual circuit fluids (front and rear braking). The comparison of the brake pedal is changed to 3: 1, designing and recreating the caliper stand to make it more precise so that it gets maximum brake performance and is better than the system used before. Static testing of the Fusena Electric Car hydraulic brake system is done by positioning the vehicle on an inclined plane at a slope of 15 and 20 with a variable driver load of 40 kg, 50 kg, 60 kg and 70 kg. The test results are that the vehicle does not experience displacement or movement. And the results of the average dynamic test of the Brake System at a speed of 27.3 km/h with an average braking distance of 171 cm = 1.71 meters and the average deceleration time is 0.26 seconds.

Implementasi Voip Server Berbasis IPV6 Dengan Raspberry PI

2019 ◽  
Vol 9 (01) ◽  
pp. 47-54
Author(s):  
Rabbai San Arif ◽  
Yuli Fitrisia ◽  
Agus Urip Ari Wibowo
Keyword(s):  
Internet Protocol ◽  
Wireless Transmission ◽  
Raspberry Pi ◽  
Test Results ◽  
Average Delay ◽  
Ipv6 Network ◽  
Ip Network ◽  
Selection Of ◽  
Better Than

Voice over Internet Protocol (VoIP) is a telecommunications technology that is able to pass the communication service in Internet Protocol networks so as to allow communicating between users in an IP network. However VoIP technology still has weakness in the Quality of Service (QoS). VOPI weaknesses is affected by the selection of the physical servers used. In this research, VoIP is configured on Linux operating system with Asterisk as VoIP application server and integrated on a Raspberry Pi by using wired and wireless network as the transmission medium. Because of depletion of IPv4 capacity that can be used on the network, it needs to be applied to VoIP system using the IPv6 network protocol with supports devices. The test results by using a wired transmission medium that has obtained are the average delay is 117.851 ms, jitter is 5.796 ms, packet loss is 0.38%, throughput is 962.861 kbps, 8.33% of CPU usage and 59.33% of memory usage. The analysis shows that the wired transmission media is better than the wireless transmission media and wireless-wired.

Kemampuan Komunikasi Matematika: Studi Komparasi Pembelajaran Number Head Together (NHT) dan Media Power Point (PPT)

2020 ◽  
Vol 3 (1) ◽  
pp. 39-50
Author(s):  
Bernadeta Ritawati ◽  
Sri Wahyuni
Keyword(s):  
Communication Skills ◽  
Hypothesis Test ◽  
Test Results ◽  
Mathematical Communication ◽  
Cluster Technique ◽  
Significance Level ◽  
Quasi Experimental ◽  
Power Point ◽  
Media Power ◽  
Better Than

This research is a quasi-experimental study that aims to determine the comparison of students' mathematical communication abilities with the cooperative learning model of the NHT and PPT media in class VII SMP Negeri 02 Ngabang. The population in this study were all students of class VII SMP 02 Ngabang consisting of 3 classes. The sample in this study was taken by using the Random Sampling Cluster technique. Class VII A as class I experimental class with 24 students and class VII B as a experimental class II with 24 students. The instruments used were pretest and posttest in the form of description. Data analysis uses the t test with a significance level of 5%. The results showed the average posttest for the NHT class was 72.5 and the average posttest for the PP class was 66.666. From the posttest hypothesis test results obtained t hitung> t tabel (1.9522> 1,667). Because t_hitung> t_tabel, H_0 is rejected and H_a is accepted. This means that students' mathematical communication skills taught with the NHT are better than using Power point media.

scholarly journals Evaluation of the Feasibility of NaCaPO4-Blended Zirconia as a New CAD/CAM Material for Dental Restoration

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3819
Author(s):  
Ting-Hsun Lan ◽  
Yu-Feng Chen ◽  
Yen-Yun Wang ◽  
Mitch M. C. Chou
Keyword(s):  
Computer Aided Design ◽  
Optical Microscope ◽  
Dental Restoration ◽  
Numerical Control ◽  
Test Results ◽  
Cnc Machine ◽  
Computer Aided ◽  
Cad Cam ◽  
Aided Design ◽  
Better Than

The computer-aided design/computer-aided manufacturing (CAD/CAM) fabrication technique has become one of the hottest topics in the dental field. This technology can be applied to fixed partial dentures, removable dentures, and implant prostheses. This study aimed to evaluate the feasibility of NaCaPO4-blended zirconia as a new CAD/CAM material. Eleven different proportional samples of zirconia and NaCaPO4 (xZyN) were prepared and characterized by X-ray diffractometry (XRD) and Vickers microhardness, and the milling property of these new samples was tested via a digital optical microscope. After calcination at 950 °C for 4 h, XRD results showed that the intensity of tetragonal ZrO2 gradually decreased with an increase in the content of NaCaPO4. Furthermore, with the increase in NaCaPO4 content, the sintering became more obvious, which improved the densification of the sintered body and reduced its porosity. Specimens went through milling by a computer numerical control (CNC) machine, and the marginal integrity revealed that being sintered at 1350 °C was better than being sintered at 950 °C. Moreover, 7Z3N showed better marginal fit than that of 6Z4N among thirty-six samples when sintered at 1350 °C (p < 0.05). The milling test results revealed that 7Z3N could be a new CAD/CAM material for dental restoration use in the future.

Feasibility investigation of a compressor rotor supported by gas foil bearings with inhomogeneous bump foils

2021 ◽  
pp. 135065012110046
Author(s):  
Hao Li ◽  
Haipeng Geng ◽  
Bo Wang ◽  
Wei Zheng
Keyword(s):  
Critical Speed ◽  
Rotor System ◽  
Experimental Result ◽  
Test Results ◽  
Rotating Speed ◽  
Foil Bearings ◽  
Dynamic Coefficients ◽  
High Order Harmonic ◽  
Compressor Rotor ◽  
Operating Points

In this paper, a rotordynamic experiment on a compressor rotor system is presented and the feasibility of gas foil bearings with inhomogeneous bump foils is verified. A push–pull device is designed to obtain the stiffness curve and the nominal clearance of foil bearings. Operating points and dynamic coefficients of the rotor system at each rotating speed are predicted. In rotordynamic analysis, an alternative model of the impeller is proposed and the critical speed is predicted by employing the finite element method, in which the dynamic coefficients of inhomogeneous foil bearings are taken into account. Compared with the experimental result, the accuracy of the prediction for the critical speed is verified to be about 14% error. Two sets of foil bearings with 22 and 41 μm nominal clearance are manufactured and tested. Test results indicate that the vibration amplitude can be greatly reduced by diminishing the bearing clearance. When foil bearings with 22 μm clearance are used, the high-order harmonic frequencies of rotor vibration are significantly inhibited, and the amplitude of the rotating frequency is obviously restricted. Thus, the foil bearing with inhomogeneous bump foils tested in this paper can meet the speed requirement of the compressor when the nominal clearance is set at 22 μm.

Influence of Collagen Status on Microstructures of Porous Collagen/TCP Composites

2007 ◽  
Vol 330-332 ◽  
pp. 495-498
Author(s):  
Chao Zou ◽  
Wen Jian Weng ◽  
Xu Liang Deng ◽  
Kui Cheng ◽  
Pi Yi Du ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Cell Growth ◽  
Tricalcium Phosphate ◽  
Freeze Drying ◽  
Alkali Treatment ◽  
Test Results ◽  
Collagen Matrices ◽  
The Difference ◽  
Porous Composites ◽  
Better Than

Two starting collagens, sponge and floc collagen, were used to prepare collagen/tricalcium phosphate (TCP) composites. The resulting composites were porous and had 200μm pore size. However, there was a difference in the microstructure of the pore walls for the composites derived from the two collagens, the pore walls in sponge collagen/TCP composite were still porous and had 200 nm micropores size, TCP particles were trapped in collagen matrices. While floc collagen/TCP composite had smooth and dense walls in which TCP particles were embedded. The difference could be attributed to the starting collagen with different status. Sponge collagen has a soft structure, which easily becomes disassembled fibrils during alkali treatment, the disassembled fibrils are integrated again to form a dense morphology for pore walls after freeze-drying. While floc collagen has already a low disassembly degree, the alkali treatment could not be able to separate the fibrils, this remains as micropores in pore walls after freeze-drying. Both porous composites are significant in bone tissue engineering or regeneration. MTT test results showed the two composites had good cytocompatibility, and sponge collagen/TCP composite was somewhat better than floc collagen/TCP composite, which could result from that micropores derived roughness in pore walls of sponge collagen/TCP composite is suitable for cell growth.

Design Forces for Drift and Damage Control: A Second Look at the Substitute Structure Approach

1994 ◽  
Vol 10 (2) ◽  
pp. 319-331 ◽  
Author(s):  
John F. Bonacci
Keyword(s):  
Reinforced Concrete ◽  
Damage Control ◽  
Dynamic Test ◽  
Frame Structures ◽  
Rc Frame ◽  
Test Results ◽  
Structure Approach ◽  
Maximum Displacement ◽  
Design Loads ◽  
Rc Frame Structures

This paper explores the development of a method that is useful for design of reinforced concrete (RC) frame structures to resist earthquakes. The substitute structure method, originally proposed in the 1970s, makes an analogy between viscously damped linear and hysteretic response for the purpose of estimating maximum displacement. The evolution of the method is retraced in order to emphasize its unique reliance on experimental results, which are needed to establish rules for assignment of substitute linear properties. Recent dynamic test results are used to extend significantly the calibration of the method, which furnishes design loads on the basis of drift and damage control.

Chaotic Dynamics Characteristic Analysis for Matrix Converter

2013 ◽  
Vol 60 (1) ◽  
pp. 78-87 ◽  
Author(s):  
Changliang Xia ◽  
Peng Song ◽  
Tingna Shi ◽  
Yan Yan
Keyword(s):  
Chaotic Dynamics ◽  
Matrix Converter ◽  
Characteristic Analysis ◽  
Dynamics Characteristic
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