A Model Study of Three-Dimensional Wind Field Analysis from Dual-Doppler Radar Data

A three-dimensional wind field analysis sollware based on the Beigng-Gucheng dual-Doppler weather radar system has been built, and evaluated by using the numerical cloud model producing storm flow and hydrometeor fields. The effects of observation noise and the spatial distribution of wind field analysis error are also investigated.

An Extreme Value Analysis of Wind Speed over the European and Siberian Parts of Arctic Region

Multiyear observed time series of wind speed for selected points of the Arctic region (data of station network from the Kola Peninsula to the Chukotka Peninsula) are used to highlight the important peculiarities of wind speed extreme statistics. How largest extremes could be simulated by climate model (the INM-CM4 model data from the Historical experiment of the CMIP5) is also discussed. Extreme value analysis yielded that a volume of observed samples of wind speeds are strictly divided into two sets of variables. Statistical properties of one population are sharply different from another. Because the common statistical conditions are the sign of identity of extreme events we therefore hypothesize that two groups of extreme wind events adhere to different circulation processes. A very important message is that the procedure of selection can be realized easily based on analysis of the cumulative distribution function. The authors estimate the properties of the modelled extremes and conclude that they consist of only the samples, adhering to one group. This evidence provides a clue that atmospheric model with a coarse spatial resolution does not simulate special mechanism responsible for appearance of largest wind speed extremes. Therefore, the tasks where extreme wind is needed cannot be explicitly solved using the output of climate model. The finding that global models are unable to capture the wind extremes is already well known, but information that they are members of group with the specific statistical conditions provides new knowledge. Generally, the implemented analytical approach allows us to detect that the extreme wind speed events adhere to different statistical models. Events located above the threshold value are much more pronounced than representatives of another group (located below the threshold value) predicted by the extrapolation of law distributions in their tail. The same situation is found in different areas of science where the data referring to the same nomenclature are adhering to different statistical models. This result motivates our interest on our ability to detect, analyze, and understand such different extremes.

Construction of Vertical Wind Profile from Satellite-Derived Winds for Objective Analysis of Wind Field

During summer Monex-79, a variety of observing systems viz. research ships, research aircrafts, constant pressure balloons and geostationary satellite etc. were deployed, besides the regular conventional observations. The purpose of these additional systems was to make the best possible data for the studies on various aspects of monsoon circulation. The present study is aimed at the construction of vertical wind profile using cloud motion vectors obtained from GOES (I-O) satellite and to examine whether the constructed wind profiles improves the representation of the monsoon system, flow pattern etc. in the objective analysis. For this purpose, climatological normals of the wind field are considered as the initial guess and the objective analyses of the wind field are made with, first using only data from conventional observations over land areas, subsequently including the constructed winds from cloud motion vectors. These analyses are then compared with the standard analyses of wind field obtained from Quick Look Atlas by T. N. Krishnamurti et al. (1979).It is inferred that satellite estimated mean wind profiles show good agreement with the mean wind profiles of the research ships with RMS errors less than 5 mps below 500 hPa and less than 8 mps above 500 hPa. It is further inferred that the inclusion of constructed winds shows a positive impact on the objective analysis and improvement is seen to be more marked in the data-sparse region of the Arabian sea. Analyses which include the constructed winds show better agreement with the standard analysis, than the analyses obtained using only conventional winds. Thus, results of our study suggest that the wind profiles constructed using cloud motion vectors are of potential use in objective analysis to depict the major circulation features over the Indian region.

Some Experiments with Multivariate Objective Analysis Scheme of Heights and Winds Using Optimum Interpolation

A two-dimensional, multitvariate objective analysis scheme for simultaneous analysis of geopotential height and wind fields has been developed over Indian and adjoining region for use in numerical weather prediction. The height-height correlations calculated using daily data of four July months (1976-1979), are used to derive the other autocorrelations and cross-correlations assuming geostropic relationship. A Gaussian function is used to model the autocorrelation function. Since the scheme is multivariate the regression coefficients (weights) are matrix.Near the equator, the geostrophic approximation relating mass and wind is decoupled in a way similar to Bergman (1979). The objective analyses were made over Indian and adjoining region for 850, 700, 500, 300 and 200 hPa levels for the period from 4 July to 8 July 1979, 12 GMT. The analyses obtained using multivariate optimum interpolation scheme depict the synoptic situations satisfactorily. The analyses were also compared with the FGGE analyses (from ECMWF) and also with the station observations by computing the root mean square (RMS) errors and the RMS errors are comparable with those obtained in other similar studies.

Simulating the Stress-Strain Response of Building under Oscillating Wind Conditions

Wind load is one of the main lateral control loads that need to be considered in the design of high-rise building structures. It is also of great engineering significance to study the influence of static wind load or time-varying wind load on the dynamic response of structures. In this paper, a high-rise building with a rectangular section (46.8 m × 27 m × 33 m) is simulated based on Ansys18.0 APDL software. The real situation of its response under no lateral wind load and different fluctuating wind load conditions is simulated and the stress and strain response of the building under steady-state and time-varying wind load is given. The results show that the upper strain of the structure under wind load is about 1/1000 of the bottom strain, and the strain of the structure shows obvious accumulation from the top to the bottom, that is, the bottom strain of the building will be higher than the top strain. The influence of time-varying wind load on building structure is related to the loading position of wind load on the structure. The results provide a basis for the structural wind resistance design of this type of building.

Wind Energy Potential Assessment in Republic of Macedonia

The paper presents the measurement campaign of wind energy potential undertaken in Republic of Macedonia on four sites from the middle of 2006. The wind data analysis has been performed for one site, following with the assessment of energy production of simulated wind park with six wind turbine generators.

浮式海上风力发电机的时域响应结构分析

As the turbine blade size becomes larger for economic power production,the coupling effect between wind turbine and floating substructure becomes important in structural assessment.Due to unsteady turbulent wind environment and corresponding coupled substructure response,time-domain analysis is required by international electrotechnical commission and class societies.Even though there are a few numerical tools available for the time domain structural analysis based on conventional coupled motion analysis with wind turbine,the application of conventional time domain analysis is impractical and inefficient for structural engineers and hull designers to perform structural strength and fatigue assessment for the required large number of design load cases since it takes huge simulation time and computational resources.Present paper introduces an efficient time-domain structural analysis practically applicable to buckling and ultimate strength assessment.Present method is based on‘lodal’response analysis and pseudo-spectral stress synthesizing technique,which makes timedomain structural analysis efficient and practical enough to be performed even in personal computing system.Practical buckling assessment methodology is also introduced applicable to the time-domain structural analyses.For application of present method,a 15-MW floating offshore wind turbine platform designed for Korean offshore wind farm projects is applied.Based on full-blown time domain structural analysis for governing design load cases,buckling and ultimate strength assessments are performed for the extreme design environments,and the class rule provided by Korean Register is checked.

Structural performance of flexible freeform panelssubjected to wind loads

An increased number of hurricanes and tornadoes have been recorded worldwide in the last decade,while research efforts to reduce wind-related damage to structures become essential.Freeform architecture,which focuses on generating complex curved shapes including streamlined shapes,has recently gained interest.This study focuses on investigating the potential of kerf panels,which have unique flexibility depending on the cut patterns and densities,to generate complex shapes for facades and their performance under wind loads.To investigate the kerf panel's potential capacity against wind loads,static and dynamic analyses were conducted for two kerf panel types with different cut densities and pre-deformed shapes.It was observed that although solid panels result in smaller displacement amplitudes,stresses,and strains in some cases,the kerf panels allow for global and local cell deformations resulting in stress reduction in various locations with the potential to reduce damage due to overstress in structures.For the predeformed kerf panels,it was observed that both the overall stress and strain responses in kerf cut arrangements were lower than those of the flat-shaped panels.This study shows the promise of the use of kerf panels in achieving both design flexibility and performance demands when exposed to service loadings.Considering that this newly proposed architectural configuration(design paradigm)for facades could revolutionize structural engineering by pushing complex freeform shapes to a standard practice that intertwines aesthetic arguments,building performance requirements,and material design considerations has the potential for significant practical applications.

Wind risk and mitigation calculator framework for determining the wind annualized risk for single- and multi-family homes to support resilient community decision-making

Communicating risks and mitigation benefits associated with natural hazards such as wind to the general public is challenging given the location-dependency of parameters and the complexity of the problem.Web tools play a crucial role in educating residents,decision-makers,and stakeholders regarding potential wind hazard losses to,for example,residential buildings.However,a notable gap exists on the practical incorporation of mitigation actions within these tools.This gap hampers the collective awareness and understanding among stakeholders,communities,and citizens regarding the tangible advantages of mitigation strategies in reducing wind-related risks.Furthermore,there exists a need to elucidate the functionality and objectives of these tools in a more accessible manner.This study aims to present and outline the wind risk and mitigation calculator tool(WRMCT)within the Hazardaware platform,which is an address-based risk assessment tool.This tool,developed for 196 counties in the Gulf of Mexico coastal area,facilitates users’education of potential risks and benefits associated with mitigation strategies.WRMCT enables users to access location-specific wind risk and interactively suggests potential mitigation actions along with economic savings to support informed decisions and residential risk reduction.WRMCT intends to enhance users’ability to make informed decisions,take proactive measures in mitigating wind hazards,and contribute to the development of resilient,residential communities.

Noise reduction in LOS wind velocity of Doppler lidar using discrete wavelet analysis

The line of sight (LOS) wind velocity can be determined from the incoherent Doppler lidar backscattering signals. Noise and interference in the measurement greatly degrade the inversion accuracy. In this paper, we apply the discrete wavelet denoising method by using biorthogonal wavelets and adopt a distance-dependent thresholds algorithm to improve the accuracy of wind velocity measurement by incoherent Doppler lidar. The noisy simulation data are processed and compared with the true LOS wind velocity. The results are compared by the evaluation of both the standard deviation and correlation coefficient. The results suggest that wavelet denoising with distance-dependent thresholds can considerably reduce the noise and interfering turbulence for wind lidar measurement.

Observations of interplanetary scintillation with a single-station mode at Urumqi

The Sun affects physical phenomena on Earth in multiple ways. In particular, the material in interplanetary space comes from coronal expansion in the form of inhomogeneous plasma flow （solar wind）, which is the primary source of the interplanetary medium. Ground-based Interplanetary Scintillation （IPS） observations are an important and effective method for measuring solar wind speed and the structures of small diameter radio sources. We discuss one mode of ground-based single-station observations： Single-Station Single-Frequency （SSSF） mode. To study the SSSF mode, a new system has been established at Urumqi Astronomical Observatory （UAO）, China, and a series of experimental observations were successfully carried out from May to December, 2008.