scholarly journals A Refined Study of Atmospheric Wind Properties in the Beijing Urban Area Based on a 325 m Meteorological Tower

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 786
Author(s):  
Shi Zhang ◽  
Bo Li ◽  
Giovanni Solari ◽  
Xinxin Zhang ◽  
Xiaoda Xu
Keyword(s):  
Aerodynamic Characteristic ◽  
Wind Profile ◽  
Measured Data ◽  
Statistical Properties ◽  
Characteristic Parameters ◽  
Local Wind ◽  
Meteorological Tower ◽  
Wind Climate ◽  
Wind Profiles ◽  
Beijing China

The urban atmospheric boundary layer (UABL) is complex due to the heterogeneous underlying city surface. The nine anemometers installed at different heights along the 325 m meteorological tower provide an opportunity to carry out a refined study of wind properties in the UABL in central Beijing, China. Based on the recent 5-year high-resolution measured data, in total, 229,488 10-min length segments of wind records related to each anemometer are reliable for further analyses. Accordingly, the statistical properties of the wind speed and direction are first analyzed to present the local wind climate in a comprehensive way. Moreover, the pattern of the wind profiles related to two typical synoptic intense events are illustrated in order to give a preliminary perspective, then the statistical properties corresponding to a series of intense windstorms are described. Here, the deviations in the wind direction occur between 200 m and 280 m of the atmosphere, which might be due to the existence of an Ekman spiral; besides this, the laws of wind profiles based on open terrain are not suitable for the UABL, and the aerodynamic characteristic parameters of the UABL based on vertical stratified structures have to be considered. The results contribute to the establishment of revised models for the wind profile and are useful for the further understanding of the structure of UABL wind.

scholarly journals Wind profile correction algorithm based on Atmospheric Boundary Layer stability profile

2021 ◽  
Author(s):  
Francisco Albuquerque Neto ◽  
Vinicius Almeida ◽  
Julia Carelli
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Wind Profile ◽  
Horizontal Wind ◽  
Boundary Layer Stability ◽  
Correction Algorithm ◽  
Horizontal Wind Speed ◽  
Study Region ◽  
Profile Correction ◽  
Wind Profiles

<p>In recent years, the use of radar wind profilers (RWP) at airports has grown significantly with the aim of supporting decision makers to maintain the safety of aircraft landings and takeoffs.</p><p>The RWP provide vertical profiles of averaged horizontal wind speed and direction and vertical wind velocity for the entire Atmospheric Boundary Layer (ABL) and beyond. In addition, RWP with Radio-Acoustic Sounding System (RASS) are able to retrieve virtual temperature profiles in the ABL.</p><p>RWP data evaluation is usually based on the so-called Doppler Beam Swinging method (DBS) which assumes homogeneity and stationarity of the wind field. Often, transient eddies violate this homogeneity and stationarity requirement. Hence, incorrect wind profiles can relate to transient eddies and present a problem for the forecast of high-impact weather phenomena in airports. This work intends to provide a method for removing outliers in such profiles based on historical data and other variables related to the Atmospheric Boundary Layer stability profile in the study region.</p><p>For this study, a dataset of almost one year retrieved from a RWP LAP3000 with RASS Extension is used for a wind profile correction algorithm development.</p><p>The algorithm consists of the detection of outliers in the wind profiles based on the thermodynamic structure of the ABL and the generation of the corrected profiles.</p><p>Results show that the algorithm is capable of identifying and correcting unrealistic variations in speed caused by transient eddies. The method can be applied as a complement to the RWP data processing for better data reliability.</p><p> </p><p>Keywords: atmospheric boundary layer; stability profile; wind profile</p>

scholarly journals Determining the Optimized Hub Height of Wind Turbine Using the Wind Resource Map of South Korea

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2949 ◽  
Author(s):  
Lee ◽  
Kim ◽  
Kang ◽  
Kim
Keyword(s):  
South Korea ◽  
Wind Turbine ◽  
Wind Profile ◽  
Lower Layer ◽  
Economic Feasibility ◽  
Strong Wind ◽  
Cost Of Energy ◽  
Height Increase ◽  
Wind Profiles ◽  
Wind Resource

Although the size of the wind turbine has become larger to improve the economic feasibility of wind power generation, whether increases in rotor diameter and hub height always lead to the optimization of energy cost remains to be seen. This paper proposes an algorithm that calculates the optimized hub height to minimize the cost of energy (COE) using the regional wind profile database. The optimized hub height was determined by identifying the minimum COE after calculating the annual energy production (AEP) and cost increase, according to hub height increase, by using the wind profiles of the wind resource map in South Korea and drawing the COE curve. The optimized hub altitude was calculated as 75~80 m in the inland plain but as 60~70 m in onshore or mountain sites, where the wind profile at the lower layer from the hub height showed relatively strong wind speed than that in inland plain. The AEP loss due to the decrease in hub height was compensated for by increasing the rotor diameter, in which case COE also decreased in the entire region of South Korea. The proposed algorithm of identifying the optimized hub height is expected to serve as a good guideline when determining the hub height according to different geographic regions.

Vertical Wind Profiles in Non-Neutral Conditions: Comparison of Models and Measurements From Frøya

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Piotr Domagalski ◽  
Lars Morten Bardal ◽  
Lars Roar Sætran
Keyword(s):  
General Description ◽  
Mean Velocity ◽  
Layer Height ◽  
Boundary Layer Height ◽  
Atmospheric Stratification ◽  
Wind Climate ◽  
Wind Profiles ◽  
The Stability ◽  
Basic Power ◽  
Neutral Conditions

This paper presents an analysis of stratification-dependent mean velocity profiles measured in a Norwegian coastal wind climate, and its comparison with models available in the literature. For this purpose, we use 3 years of observations from a 100 m meteorological mast located at the Frøya island (150 km west of Trondheim, Norway), equipped with a set of two-dimensional (2D) ultrasonic anemometers. The presented analysis is preceded by a general description of the site wind climate, the atmospheric stratification, the roughness length, and the surface layer height. Finally, the measured wind velocity profile is compared with selected models: the basic power and logarithmic law and the stability-corrected models: stability-corrected logarithmic wind profile, the Panofsky and Dutton model, the Peña boundary layer height corrected model, and the correlation-based Smedman-Högström model.

scholarly journals Impact of Environmental Heterogeneity on the Dynamics of a Dissipating Supercell Thunderstorm

2015 ◽  
Vol 143 (10) ◽  
pp. 4244-4277 ◽  
Author(s):  
Casey E. Davenport ◽  
Matthew D. Parker
Keyword(s):  
Environmental Heterogeneity ◽  
Wind Profile ◽  
Environmental Temperature ◽  
Dominant Role ◽  
Source Region ◽  
Vertical Acceleration ◽  
Supercell Thunderstorm ◽  
The Mean ◽  
Wind Profiles ◽  
Morphology Changes

Abstract On 9 June 2009, the Second Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX2) sampled a supercell as it traversed through an increasingly stable environment with decreasing bulk shear and storm-relative helicity. To investigate the impacts of the observed environmental heterogeneity on storm morphology, a series of idealized simulations were conducted. Utilizing the base-state substitution modeling technique, the separate effects of the changing wind profile and the increasingly stable boundary layer were evaluated. The varying base-state environment in each experiment elevated the mean source region of updraft parcels. These elevated parcels were drier (with less instability), and more negatively impacted by entrainment. Thus, as the updraft ingested a larger fraction of elevated parcels, its buoyancy was depleted, leading to demise. Unsurprisingly, the increasingly stable low-level environment played a dominant role in this process; however, wind profile modifications also elevated the mean source region of updraft parcels, which independently impacted storm strength and morphology. Changes to the storm’s internal dynamical processes were assessed using the diagnostic pressure equation. The evolution in total vertical acceleration was primarily related to changes in accelerations that were connected to updraft rotation, as well as shifts in buoyancy. The dynamical accelerations weakened and became maximized at a different altitude, resulting in an increasingly elevated updraft parcel source region. Overall, this study finds that a shifting updraft parcel source region can significantly impact storm maintenance; importantly, such a shift can result from changes in environmental temperature, moisture, or wind profiles.

A Solar Time Classification for Meteorological Use

1958 ◽  
Vol 39 (11) ◽  
pp. 569-573 ◽  
Author(s):  
Irving A. Singer ◽  
Gilbert S. Raynor
Keyword(s):  
Diurnal Cycle ◽  
Wind Profile ◽  
Meteorological Data ◽  
National Laboratory ◽  
Brookhaven National Laboratory ◽  
Temperature Data ◽  
Lapse Rate ◽  
Time System ◽  
Meteorological Tower ◽  
Solar Time

In order to effect a more consistent grouping of hourly meteorological data influenced by the diurnal cycle, a chronology based on the time of sunrise and sunset was devised. A code classified all hours within each bi-weekly period by this time system. The classification was further extended by dividing the year into solar seasons, defined as periods of time during which the distribution of solar hours is uniform. The use of solar time as a major classification in the analysis of two years of hourly wind and temperature data obtained from six levels on the 420-ft meteorological tower at Brookhaven National Laboratory resulted in a better understanding of the relationships between the variables than could have been obtained by the use of standard time. Results of several lapse-rate and wind-profile studies made using both standard and solar time demonstrated the advantage of the latter system. Application of this method to other problems and regions is discussed.

Visualization of Relative Wind Profiles in Relation to Actual Weather Conditions of Ship Routes

2017 ◽  
Author(s):  
Lokukaluge P. Perera ◽  
Brage Mo ◽  
Matthias P. Nowak
Keyword(s):  
Large Scale ◽  
Wind Profile ◽  
Weather Conditions ◽  
Data Sets ◽  
Navigation Data ◽  
External Data ◽  
Wind Profiles ◽  
Tools And Techniques ◽  
Ship Performance ◽  
Relative Wind

Ship performance and navigation data are collected by vessels that are equipped with various supervisory control and data acquisition systems (SCADA). Such information is collected as large-scale data sets, therefore various analysis tools and techniques are required to extract useful information from the same. The extracted information on ship performance and navigation conditions can be used to implement energy efficiency and emission control applications (i.e. weather routing type applications) on these vessels. Hence, this study proposes to develop data visualizing methods in order to extract ship performance and navigation information from the respective data sets in relation to weather conditions. The relative wind (i.e. apparent wind) profile (i.e. wind speed and direction) collected by onboard sensors and absolute weather conditions, which are extracted from external data sources by using position and time information a selected vessel (i.e. from the recorded ship routes), are considered. Hence, the relative wind profile of the vessel is compared with actual weather conditions to visualize ship performance and navigation parameters relationships, as the main contribution. It is believed that such relationships can be used to develop appropriate mathematical models to predict ship performance and navigation conditions under various weather conditions.

scholarly journals A New Parametric Tropical Cyclone Tangential Wind Profile Model

2013 ◽  
Vol 141 (6) ◽  
pp. 1884-1909 ◽  
Author(s):  
Vincent T. Wood ◽  
Luther W. White ◽  
Hugh E. Willoughby ◽  
David P. Jorgensen
Keyword(s):  
Tropical Cyclone ◽  
Wind Profile ◽  
Tangential Velocity ◽  
Pressure Rise ◽  
Central Pressure ◽  
Velocity Parameter ◽  
Profile Model ◽  
Tangential Wind ◽  
Multiple Maxima ◽  
Wind Profiles

Abstract A new parametric tropical cyclone (TC) wind profile model is presented for depicting representative surface pressure profiles corresponding to multiple-maxima wind profiles that exhibit single-, dual-, and triple-maximum concentric-eyewall wind peaks associated with the primary (inner), secondary (first outer), and tertiary (second outer) complete rings of enhanced radar reflectivity. One profile employs five key parameters: tangential velocity maximum, radius of the maximum, and three different shape velocity parameters related to the shape of the profile. After tailoring the model for TC applications, a gradient wind is computed from a cyclostrophic wind formulated in terms of the cyclostrophic Rossby number. A pressure, via cyclostrophic balance, was partitioned into separate pressure components that corresponded to multiple-maxima cyclostrophic wind profiles in order to quantitatively evaluate the significant fluctuations in central pressure deficits. The model TC intensity in terms of varying growth, size, and decay velocity profiles was analyzed in relation to changing each of five key parameters. Analytical results show that the first shape velocity parameter, changing a sharply to broadly peaked wind profile, increases the TC intensity and size by producing the corresponding central pressure fall. An increase (decrease) in the second (third) shape velocity parameter yields the pressure rise (fall) by decreasing (increasing) the inner (outer) wind profile inside (outside) the radius of the maximum. When a single-maximum tangential wind profile evolves to multiple-maxima tangential wind profiles during an eye replacement cycle, the pressure falls and rises are sensitively fluctuated.

scholarly journals Design and Implementation of a Low Power Wind Turbine Emulator Through the Induction Motor-Permanent Magnet Generator Arrangement

2020 ◽  
Vol 29 (54) ◽  
pp. e10530
Author(s):  
David Felipe Bajonero-Sandoval ◽  
Jeyson Sanabria-Vargas ◽  
César Leonardo Trujillo-Rodriguez
Keyword(s):  
Wind Speed ◽  
Low Power ◽  
Wind Turbine ◽  
Permanent Magnet ◽  
Induction Motor ◽  
Wind Profile ◽  
Labview Software ◽  
Three Phase ◽  
Wind Profiles ◽  
Permanent Magnet Generator

This paper presents the design and construction stage of a low power wind turbine emulator, which is used at the laboratory level, to reproduce different wind profiles. There are several types of wind emulators, among which the wind tunnel emulators stand out. These emulators use a motor with a propeller on their axis to obtain the desired wind speed. However, in the present work -and done from a computer- speed control is developed for a three-phase induction motor, thus driving a permanent magnet generator. The motor-generator group is controlled through a program developed in the Labview software. Also, it has the particularity of operating automatically, being able to load different speed data. Such data is associated with a particular power that takes into account the selected wind profile and can operate through manual control of the wind speed. However, this depends on the frequency given. The emulator operation is validated experimentally through two scenarios: the first one emulates the curve presented by the Eolos turbine and subsequently compares the results obtained, whereas the second one loads the wind profile of Uribía-Guajira -a region in Colombia-  achieving that the emulated wind profile can be accurately seen in the loaded wind profile.

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