scholarly journals The characteristics of weather-related wind load parameters and wind 2 power quality over the Dabanchen strong gale area

2021 ◽  
Author(s):  
Yu Xin ◽  
Zonhui Liu ◽  
Qing He
Keyword(s):  
Three Dimensional ◽  
Measurement Data ◽  
Wind Load ◽  
Strong Wind ◽  
Dynamic Interactions ◽  
Integral Scale ◽  
Turbulence Structures ◽  
Wind Speeds ◽  
Three Dimensional Measurement ◽  
Ultrasonic Anemometer

Abstract Analysis of data from cup and ultrasonic anemometers on a 100 m-tall wind mast in the Dabanchen Canyon reveals that the turbulence intensities, gust factors, and peak factors measured by cup anemometers tend to be severely undervalued compared to longitudinal values from an ultrasonic anemometer, and onsite three-dimensional measurement data are preferred for weather-related wind load calculation. This difference is related to the rotating responses of cup anemometers during wind speed acceleration or deceleration and the higher vertical fluctuation speeds driven by dynamic interactions with the sloped canyon terrain. The higher lateral turbulence is key consideration for determining wind turbine classes in Danbanchen strong wind area. The longitudinal gust and peak factors under wind speeds exceeding 25.0 m s−1 are comparable with those of typhoon-prone open, flat regions. The chances of high turbulence and unstable stratification convective processes are very high; thus, wind power collection efficiencies are not high. Except the longitudinal turbulence integral scale, China’s wind-resistance codes are not applicable due to occasional undesirable strong gales with extraordinary turbulence structures. The measured vertical power spectral density of fluctuating wind in the high-frequency domain cannot reflect the rapidly adapting features of the vast terrain under strong gales.

scholarly journals The characteristics of weather-related wind load parameters and wind power quality over the Dabanchen strong gale area

2021 ◽  
Author(s):  
Yu Xin ◽  
Zonhui Liu ◽  
Qing He
Keyword(s):  
Wind Power ◽  
Three Dimensional ◽  
Measurement Data ◽  
Wind Load ◽  
Strong Wind ◽  
Dynamic Interactions ◽  
Integral Scale ◽  
Turbulence Structures ◽  
Wind Speeds ◽  
Three Dimensional Measurement

Abstract Analysis of data from cup and ultrasonic anemometers on a 100 m-tall wind mast in the Dabanchen Canyon reveals that the turbulence intensities, gust factors, and peak factors measured by cup anemometers tend to be severely undervalued compared to longitudinal values from an ultrasonic anemometer, and onsite three-dimensional measurement data are preferred for weather-related wind load calculation. This difference is related to the rotating responses of cup anemometers during wind speed acceleration or deceleration and the higher vertical fluctuation speeds driven by dynamic interactions with the sloped canyon terrain. The higher lateral turbulence is key consideration for determining wind turbine classes in Danbanchen strong wind area. The longitudinal gust and peak factors under wind speeds exceeding 25.0 m s−1 are comparable with those of typhoon-prone open, flat regions. The chances of high turbulence and unstable stratification convective processes are very high; thus, wind power collection efficiencies are not high. Except the longitudinal turbulence integral scale, China’s wind-resistance codes are not applicable due to occasional undesirable strong gales with extraordinary turbulence structures. The measured vertical power spectral density of fluctuating wind in the high-frequency domain cannot reflect the rapidly adapting features of the vast terrain under strong gales.

Detecting the Underground Displacement by Integrated Sensor Equipped with Three-Dimensional Measurement Method

2013 ◽  
Vol 336-338 ◽  
pp. 172-179 ◽  
Author(s):  
Guo Qing Jiang ◽  
Qing Li ◽  
Yang Ming Xie
Keyword(s):  
Measurement Method ◽  
Three Dimensional ◽  
Measurement Data ◽  
High Sensitivity ◽  
Integrated Sensor ◽  
High Data ◽  
Dimensional Measurement ◽  
Real Time Measurement ◽  
Three Dimensional Measurement ◽  
Scope Of Application

Measurement of underground displacement is of great significance. Now, there are various measuring methods to detect underground displacement. But each of them has its own scope of application and limitation. According to actual demand, this paper puts forward an integrated sensor which utilize three-dimensional measurement method to supervise the underground displacement. This sensor can not only measure the size and direction of the displacement, but also can achieve real-time measurement data. Method and realization of displacement measurement are introduced, as well as the experimental data. Comparing with other several measurement methods, three-dimensional measurement method is much better than the normal ones, including high data transmission speed, high sensitivity, strong practicability etc.

Three-Dimensional Measurement Data Registration Based on Planar Circle Target

2013 ◽  
Vol 33 (2) ◽  
pp. 0215002 ◽  
Author(s):  
魏新国 Wei Xinguo ◽  
刘涛 Liu Tao ◽  
刘震 Liu Zhen
Keyword(s):  
Three Dimensional ◽  
Measurement Data ◽  
Data Registration ◽  
Dimensional Measurement ◽  
Three Dimensional Measurement

Exploring three-dimensional coupled fire–atmosphere interactions downwind of wind-driven surface fires and their influence on backfires using the HIGRAD-FIRETEC model

2011 ◽  
Vol 20 (6) ◽  
pp. 734 ◽  
Author(s):  
J.-L. Dupuy ◽  
R. R. Linn ◽  
V. Konovalov ◽  
F. Pimont ◽  
J. A. Vega ◽  
...  
Keyword(s):  
Reasonable Agreement ◽  
Three Dimensional ◽  
Limited Range ◽  
Two Dimensions ◽  
Strong Wind ◽  
Wind Speeds ◽  
Surface Fires ◽  
Atmosphere Interaction ◽  
Weak Wind ◽  
Three Dimensional Simulations

The obstruction of ambient winds and the possible existence of indrafts downwind of a wildfire are aspects of coupled fire–atmosphere interaction influencing the effectiveness of a backfiring operation. The fire-influenced winds behind a headfire as well as their influences on backfire spread are explored using the three-dimensional HIGRAD-FIRETEC model. Fires are simulated under weak to strong wind speeds and in shrubland and grassland fuel types. The importance of three-dimensionality in the simulation of such phenomena is demonstrated. Results suggest that when fire–atmosphere interaction is constrained to two-dimensions, the limitations of air moving through the head fire could lead to overestimation of downwind indrafts and effectiveness of backfiring. Three-dimensional simulations in surface fuels suggest that backfires benefit from the obstruction of ambient winds and potentially the existence of an indraft flow in only a limited range of environmental conditions. Simulations show that flows are most favourable when the wildfire is driven downslope by a weak wind and the backfire is ignited at bottom of the slope. Model simulations are compared with backfiring experiments conducted in a dense shrubland. Although this exercise encountered significant difficulties linked to the ambient winds data and their incorporation into the simulation, predictions and observations are in reasonable agreement.

Time-Resolved Near-Wake Measurements of a 2MW Wind Turbine

2013 ◽  
Author(s):  
Michel Mansour ◽  
Caglar Atalayer ◽  
Ndaona Chokani ◽  
Reza Abhari
Keyword(s):  
Wind Turbine ◽  
Real Time ◽  
Three Dimensional ◽  
Pressure Sensors ◽  
Fast Response ◽  
Near Wake ◽  
Time Resolved ◽  
Wind Speeds ◽  
Ultrasonic Anemometer ◽  
Yaw Angle

This paper presents time-resolved velocity measurements performed in the near wake of a multi-megawatt wind turbine, using a novel nacelle-mounted fast-response aerodynamic probe. The aerodynamic probe, which has been developed at ETH Zurich, consists of a hemispherical 5-hole probe equipped with fast-pressure sensors. The probe has a measurement uncertainty of ±0.1m/s and a measurement bandwidth of 65Hz. In addition to measurement of the three-dimensional wind velocity vector, the probe is instrumented for the real-time monitoring of meteorological conditions. The measured data are processed in real-time, stored on on-board and accessible via a GPRS modem. As the aerodynamic probe is installed adjacent to the wind turbine’s ultrasonic anemometer, the measurements of the two systems can be compared. The measured wind speeds are found to be in very good agreement and remains on an averaged within ±0.24m/s deviation to the ultrasonic anemometer. The measured yaw angle shows an average offset of −7.5°. This difference is observed since the ultrasonic anemometer does not accurately capture the turning of the flow across the wind turbine’s rotor. From the time-resolved measurements of the aerodynamic probe, the phase-lock averaged measurements show that over one blade passing period the turbulence intensity varies from 13 to 24%, with a maximum degree of anisotropy above 1.4. It is found that a hub passage vortex, which extends over more than 50% of the blade passage width, is present. Thus, from a turbine control perspective the actual placement of the ultrasonic anemometer, even when corrected, can lead to high yaw angle misalignment when the wind turbine is located in moderately or highly complex terrain.

Nano-Micro Geometric Modeling Using Microscopic Image

2012 ◽  
Vol 523-524 ◽  
pp. 345-349 ◽  
Author(s):  
Shin Usuki ◽  
Kenjiro Takai Miura
Keyword(s):  
Geometric Modeling ◽  
High Speed ◽  
Large Scale ◽  
Early Stage ◽  
Three Dimensional ◽  
Measurement Data ◽  
Stage Of Development ◽  
Three Dimensional Measurement ◽  
Micro Features ◽  
Effective Use

In recent years, there are a lot of active researches on nano-micro manufacturing and metrology, since not only industrial fields but also medical fields require higher accuracy with respect to miniaturizing size of the target. However, we cannot make an effective use of three dimensional measurement data for the nano-micro design and manufacturing due to a wide variety of instruments, resolutions, and noises. In fact, the nano-micro geometric modeling is at an early stage of development in spite of its importance for the next generation. In order to find a solution to this problem, we propose to combine the multi-resolution processing with the microscopic images for high speed and non-destructive geometric modeling as well as for the homogeneous modeling from micro features to macro ones. This research includes measurement data tiling between different instruments, high resolution optical microscopic imaging, focus judgment of three dimensional microscopic data, and large scale point crowd processing. These built models are potentially applied to in-line inspections and numerical simulations. Therefore, the nano-micro geometric modeling contribute to further developments of ultra precise manufacturing and the biotechnology.

scholarly journals Optical Theodolite Based Rationality Check of Measurement Data From Pulse Radar

2021 ◽  
Author(s):  
Shaolin Hu ◽  
Wenqiaqng Jiang ◽  
Jiahui Liang ◽  
Jian Li
Keyword(s):  
Pitch Angle ◽  
Three Dimensional ◽  
Measurement Data ◽  
Radar Data ◽  
Measuring Channel ◽  
Dimensional Measurement ◽  
Pulse Radar ◽  
Angle Measuring ◽  
Three Dimensional Measurement ◽  
Optical Theodolite

Abstract Theodolite and radar are important measurement and control devices in aviation, aerospace and other fields. In order to make sure the tracking measurement and navigation control of aircraft and spacecraft safely, this paper creatively proposes a novel method to check the rationality of the three-dimensional measurement data (distance, azimuth and pitch angle) of the pulse radar by using the two-dimensional measurement data (azimuth and pitch angle) of the optical theodolite. Specifically, three different rationality checking functions are constructed for the three different cases of unreliable ranging channel, unreliable angle measuring channel and unreliable ranging and angle measuring channels, and are used for the rationality checking of radar data in the above three cases respectively. Simulation results show that the correct rate is more than 95% as long as the data measured by optical theodolite are reliable.

scholarly journals PRECISIONS MEASUREMENT FOR THE GRASP OF WELDING DEFORMATION AMOUNT OF TIME SERIES FOR LARGE-SCALE INDUSTRIAL PRODUCTS

2015 ◽  
Vol XL-4/W5 ◽  
pp. 153-157
Author(s):  
R. Abe ◽  
K. Hamada ◽  
N. Hirata ◽  
R. Tamura ◽  
N. Nishi
Keyword(s):  
Time Series ◽  
Quality Management ◽  
Construction Industry ◽  
Large Scale ◽  
Three Dimensional ◽  
Measurement Data ◽  
Welding Deformation ◽  
Dimensional Measurement ◽  
Three Dimensional Measurement ◽  
Deformation Amount

As well as the BIM of quality management in the construction industry, demand for quality management of the manufacturing process of the member is higher in shipbuilding field. The time series of three-dimensional deformation of the each process, and are accurately be grasped strongly demanded. In this study, we focused on the shipbuilding field, will be examined three-dimensional measurement method. The shipyard, since a large equipment and components are intricately arranged in a limited space, the installation of the measuring equipment and the target is limited. There is also the element to be measured is moved in each process, the establishment of the reference point for time series comparison is necessary to devise. In this paper will be discussed method for measuring the welding deformation in time series by using a total station. In particular, by using a plurality of measurement data obtained from this approach and evaluated the amount of deformation of each process.

Sign in / Sign up

Export Citation Format

Share Document