High-speed SAR prediction for mass production stages in a factory by H-field measurements [cellular radio applications]

Author(s):  
K. Ogawa ◽  
A. Ozaki ◽  
S. Kajiwara ◽  
A. Yamamoto ◽  
Y. Koyanagi ◽  
...  
Author(s):  
Adam R. Hickman ◽  
Scott C. Morris

Flow field measurements of a high-speed axial compressor are presented during pre-stall and post-stall conditions. The paper provides an analysis of measurements from a circumferential array of unsteady shroud static pressure sensors during stall cell development. At low-speed, the stall cell approached a stable size in approximately two rotor revolutions. At higher speeds, the stall cell developed within a short amount of time after stall inception, but then fluctuated in circumferential extent as the compressor transiently approached a stable post-stall operating point. The size of the stall cell was found to be related to the annulus average flow coefficient. A discussion of Phase-Locked Average (PLA) statistics on flow field measurements during stable operation is also included. In conditions where rotating stall is present, flow field measurements can be Double Phase-Locked Averaged (DPLA) using a once-per-revolution (1/Rev) pulse and the period of the stall cell. The DPLA method provides greater detail and understanding into the structure of the stall cell. DPLA data indicated that a stalled compressor annulus can be considered to contained three main regions: over-pressurized passages, stalled passages, and recovering passages. Within the over-pressured region, rotor passages exhibited increased blade loading and pressure ratio compared to pre-stall values.


2012 ◽  
Vol 100 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Yung-Yen Ko ◽  
Cheng-Hsing Chen ◽  
Ing-Tsang Hoe ◽  
Shin-Tsyr Wang

2021 ◽  
Author(s):  
Haochen Han ◽  
Yong Zhang ◽  
Jia Chen ◽  
Qi Sun ◽  
Zhimeng Fang ◽  
...  

Abstract High-speed wired drill pipe and its corresponding communication technology not only can achieve high-speed transmission rate and high-capacity, but also can realize real-time monitoring and dual-way communication in whole section, which can prevent downhole problems effectively. As a series system, the homogeneity and robustness of these wired drill pipes are crucial. This paper focuses on how to overcome the difficulty in manufacturing process of information drill pipe and complete the validation test. In order to guarantee the quality of information drill pipe and satisfy the technological requirements of mass production, we optimize the manufacturing process and put forward reasonable test techniques. The optimizations of manufacturing process include the analysis on constant tension of pressure pipe, quantitative cutting pipe and perforation in pipe nozzle. The testing techniques includes magnetic coupling coil impedance test, high pressure test, communication performance test of both single pipe and series system. The test result can be judged and evaluated by the attenuation value of the signal attenuation test and the signal reflection waveform as well as sealing reliability. With the help of the optimization of the manufacturing process and the application of new tooling, the quality and robustness of information drill pipe is improved obviously. Pass rate in primary assembly is increased from 70% to 92%. After the second assembly, pass rate can be increased to 99.5%. Besides, the work efficiency is greatly improved and the process requirements of mass production are satisfied. The validation test can screen out the drill pipe with poor quality and performance effectively thus to improve the reliability of the whole system. By means of the improvement of manufacturing and the validation test, the comprehensive pass rate of information drill pipes is increased from 84% to 95%. During three field tests in Jilin and Daqing Oilfield, the information drill pipes functioned well and accomplished all the test tasks successfully. High-speed wired drill pipe can improve the downhole data transmission on a large margin. The theorical transmission rate can be up to 100 kbps, 10,000 times as much as the traditional mud impulse telemetry. The manufacturing optimization and test technology can guarantee the performance and realize downhole data highway.


2019 ◽  
Vol 9 (23) ◽  
pp. 4991 ◽  
Author(s):  
Li ◽  
Su ◽  
Kaewunruen

A novel three-dimensional (3D) coupled train-track-soil interaction model is developed based on the multi-body simulation (MBS) principle and finite element modeling (FEM) theory using LS-DYNA. The novel model is capable of determining the highspeed effects of trains on track and foundation. The soils in this model are treated as saturated media. The wheel-rail dynamic interactions under the track irregularity are developed based on the Hertz contact theory. This model was validated by comparing its numerical results with experimental results obtained from field measurements and a good agreement was established. The one-layered saturated soil model is firstly developed to investigate the vibration responses of pore water pressures, effective and total stresses, and displacements of soils under different train speeds and soil moduli. The multi-layered soils with and without piles are then developed to highlight the influences of multi-layered soils and piles on the ground vibration responses. The effects of water on the train-track dynamic interactions are also presented. The original insight from this study provides a new and better understanding into saturated ground vibration responses in high-speed railway systems using slab tracks in practice. This insight will help track engineers to inspect, maintain, and improve soil conditions effectively, resulting in a seamless railway operation.


2019 ◽  
Vol 11 (1) ◽  
pp. 80-87 ◽  
Author(s):  
Jitendra Kumar Saini ◽  
Avireni Srinivasulu ◽  
Renu Kumawat

The transformation from the development of enabling technology to mass production of consumer-centric semiconductor products has empowered the designers to consider characteristics like robustness, compactness, efficiency, and scalability of the product as implicit pre-cursors. The Carbon Nanotube Field Effect Transistor (CNFET) is the present day technology. In this manuscript, we have used CNFET as the enabling technology to design a 1-bit Full Adder (1b-FA16) with overflow detection. The proposed 1b-FA16 is designed using 16 transistors. Finally, the proposed 1b-FA16 is further used to design a Ripple Carry Adder (RCA), Carry Look Ahead Adder (CLA) circuit and RCA with overflow bit detection. Methods and Results: The proposed 1b-FA16 circuit was designed with CNFET technology simulated at 32 nm with a voltage supply of +0.9 V using the Cadence Virtuoso CAD tool. The model used is Stanford PTM. Comparison of the existing full adder designs with the proposed 1b-FA16 design was done to validate the improvements in terms of power, delay and Power Delay Product (PDP). Table 2, shows the results of comparison for the proposed 1b-FA16 with the existing full adder designs implemented using CNFET for parameters like power, delay and power delay product. Conclusion: It can be concluded that the proposed 1b-FA16 yielded better results as compared to the existing full adder designs implemented using CNFET. The improvement in power, delay and power delay product was approximately 11%, 9% and 24% respectively. Hence, the proposed circuit implemented using CNFET gives a substantial rate of improvements over the existing circuits.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Jinying Guo ◽  
Huailong Shi ◽  
Fansong Li ◽  
Pingbo Wu

The vibrations in the flexible car bodies of the high-speed electric multiple units (EMUs) and their coupling effects with the bogies and other types of equipment vibrating have lead issues for railway operators and gained interest for researchers. Other than a numerical investigation, field measurements on the vibrating characteristics of the car body (CB) and its suspended equipment (CBSE) for a high-speed railway vehicle were performed to elaborate the vibrating characteristics on the CB and its CBSE. In this long-term tracking test, the running stability of vehicle and wheel-rail interaction were also examined with the increase of operation distance (OD), a total of 2,400,000 km. The test configuration and arrangements are introduced first, followed by the data analysis in time and frequency domains. It is seen that the wheelset conicity increases 0.008 per 10,000 km, which increases approximately linearly with the OD from 0.10 to 0.40. Two types of wheel treads, S1002CN and LMB10, have different ranges in conicity and reprofiling cycles. The lateral accelerations on CB in a downward-running case (0.5 g) are much greater than that in upward-running case (0.2 g) corresponding to the vehicle stability differences. The 15 Hz low-pass filtered acceleration on CB experiences a maximum of 0.10 g and an averaged amplitude around 0.05 g, whereas the frequency spectrum has peaks of 0.01 g on CB and 0.1 g on CBSE. It states that an elastic suspension between the CBSE and the CB prevents the high-frequency vibration from the CB.


1979 ◽  
Vol 46 (4) ◽  
pp. 925-930 ◽  
Author(s):  
N. K. Mital ◽  
A. I. King

The angular acceleration of a rigid body with respect to a body-fixed (moving) frame can be reliably computed from nine acceleration field measurements. Noncommutativity of finite rotations causes computational problems during numerical integration to obtain the transformation matrix, especially when the rotation is three-dimensional and there are errors in the measured linear accelerations. A method based on the orientation vector concept is formulated and tested against hypothetical data. The rigid-body rotations computed from linear accelerometer data from impact acceleration tests are compared against those obtained from three-dimensional analysis of high speed movie films.


2018 ◽  
Vol 8 (2) ◽  
pp. 82-88
Author(s):  
Elina V. DANILOVA

The article deals with the design methodology invented by the French architect Jean-Nicolas-Louis Durand as a machine of mass production of architecture. The author describes the historical and temporal background which determined the requirements for the design and construction of a large number of public buildings. The historical parallel between diff erent epochs when urban expansion became the reason for the invention of methods of high-speed and simple design of various objects is studied. Duran’s methodology is described based on the analysis of two theoretical works. The positive and negative aspects of the project approach based on such methodology are investigated. The role of Duran’s work in the process of creating architecture for the modern city is established.


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