Abstract
This paper analyzes La Rumorosa I Wind Farm's wind states and their characteristics in the operation of two wind
turbines over the course of one year of records. This information identifies the impact of wind states on wind power output. The
study used the Gaussian Mixture Model to classify the occurrence and frequency of the dominant wind states in the generation
of energy from the turbines. Results were obtained for mesoscale wind states and local scale wind states, such as cold fronts and
Santa Ana winds, as well as daytime, nighttime and hot days, respectively, which were statistically analyzed to determine their
relationship to power output by generating power and power coefficient curves. Between the cut-in speed and the rated speed of
the wind turbines, cold fronts show higher efficiency, unlike nighttime wind states, which are the most efficient past the rated
speed. In addition, cold fronts are also those that occur to the greatest extent, contributing 31.26% of the energy produced per
year, compared with the Santa Ana winds, which occur to a lesser extent; however, they contribute 22.11% of the energy
produced per year.
Abstract
Aerodynamic shape optimization is very useful for enhancing the performance of wind-sensitive structures.
However, shape parameterization, as the first step in the pipeline of aerodynamic shape optimization, still heavily depends on
empirical judgment. If not done properly, the resulting small design space may fail to cover many promising shapes, and hence
hinder realizing the full potential of aerodynamic shape optimization. To this end, developing a novel shape parameterization
scheme that can reflect real-world complexities while being simple enough for the subsequent optimization process is important.
This study proposes a machine learning-based scheme that can automatically learn a low-dimensional latent representation of
complex aerodynamic shapes for bluff-body wind-sensitive structures. The resulting latent representation (as design variables for
aerodynamic shape optimization) is composed of both discrete and continuous variables, which are embedded in a hierarchy
structure. In addition to being intuitive and interpretable, the mixed discrete and continuous variables with the hierarchy structure
allow stakeholders to narrow the search space selectively based on their interests. As a proof-of-concept study, shape
parameterization examples of tall building cross sections are used to demonstrate the promising features of the proposed scheme
and guide future investigations on data-driven parameterization for aerodynamic shape optimization of wind-sensitive structures.
Abstract
To investigate the wind load characteristics of a large-span spherical shell structure, a rigid model pressure test was
conducted in a wind tunnel laboratory. The study aimed to examine the impact of various external structures and internal
stacking forms on the wind loads of a spherical shell structure in a practical engineering project. This project features two
adjacent spherical structures, each spanning 130 m and standing 67 m tall. These two structures are connected by trestles and a
transfer station. Variations in the shape factor and the integral force coefficient of the structure were compared and analyzed
under different test cases. The results indicate that when two structures are arranged in series, with the adjacent structure
positioned upstream, the shape factor of the structure is most affected, resulting in a significant reduction effect at the bottom of
the windward surface. Compared to the external structure, the impact of various internal stacking forms on the shape factor of
the structure is relatively weak. The adjacent structure significantly improves the wind resistance of the main structure. The
integral force coefficient of the structure reaches its peak when internal stacking is full and is at its lowest when there is no
internal stacking.
Key Words
external structure; integral force coefficient; internal stacking; shape factor; spherical shell structure; wind load;
wind tunnel test
Address
Xiaobing Liu:1)State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,
Shijiazhuang Tiedao University, Shijiazhuang 050043, China
2)Innovation Center for Wind Engineering and Wind Energy Technology of Hebei Province, Shijiazhuang 050043, China
3)School of Civil Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China
Anjie Chen:School of Civil Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China
Qun Yang:1)State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,
Shijiazhuang Tiedao University, Shijiazhuang 050043, China
2)Innovation Center for Wind Engineering and Wind Energy Technology of Hebei Province, Shijiazhuang 050043, China
3)School of Civil Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China
Bin Feng:School of Civil Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China
Xuedong Tian:School of Civil Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China
Abstract
This paper presents a numerical simulation method for snow drift that takes into account the cohesion effect of snow
particles. The critical state of free collapse accumulation of idealized snow particles is used to indirectly infer the effect of interparticle interactions on snow transport and re-accumulation. With the help of the Hertz-Mindlin with JKR cohesion contact
model, the particle angle of repose is calibrated with a number of contact parameters through numerical experiment. The surface
energy for a given property of snow particles is determined using the observed snow angle of repose, and a continuous-discrete
snow drift two-way coupled numerical model incorporating these optimized contact parameters is developed. The snow
redistribution pattern on a stepped flat roof structure is simulated, and the results are found to be consistent with those of the field
measured in terms of phenomena and general laws, verifying the achievability and effectiveness of the presented method. To
eliminate the influence of environmental conditions, wind tunnel tests are also conducted, and it is found that the reconstructed
depth and reaccumulated angle of snowdrift resulting from the numerical simulation are in closer agreement with the
experimental results, further confirming the enhancement achieved by introducing the contact effect.
Key Words
contact effect; coupling model; Eulerian-Lagrangian framework; numerical simulation; snow drift; surface energy
Address
Bin Wang:1)1Department of Bridge Engineering, Southwest Jiaotong University, Chengdu 610031, China 2)Wind engineering key laboratory of Sichuan province, Chengdu 610031, China 3)National Key Laboratory of Bridge Intelligent and Green Construction, Southwest Jiaotong University, Chengdu 611756, China
Shengran Hao:1)1Department of Bridge Engineering, Southwest Jiaotong University, Chengdu 610031, China 2)Wind engineering key laboratory of Sichuan province, Chengdu 610031, China 3)National Key Laboratory of Bridge Intelligent and Green Construction, Southwest Jiaotong University, Chengdu 611756, China
Shu Liu:1)1Department of Bridge Engineering, Southwest Jiaotong University, Chengdu 610031, China 2)Wind engineering key laboratory of Sichuan province, Chengdu 610031, China 3)National Key Laboratory of Bridge Intelligent and Green Construction, Southwest Jiaotong University, Chengdu 611756, China
Duote Liu:School of Architecture and Civil Engineering, Chengdu University, Chengdu 610106, China
Yongle Li:1)1Department of Bridge Engineering, Southwest Jiaotong University, Chengdu 610031, China 2)Wind engineering key laboratory of Sichuan province, Chengdu 610031, China 3)National Key Laboratory of Bridge Intelligent and Green Construction, Southwest Jiaotong University, Chengdu 611756, China
Haicui Wang:Faculty of Construction and Environment, The Hong Kong Polytechnic University, Hong Kong 999077, China
Abstract
Wind comfort in cold climates is one of the most essential factors for urban planners. This issue is particularly
important for sidewalks that are in line with the prevailing wind flow and surrounded by high-rise buildings. Imam Street near
the University Square in Tabriz is one of the passages that struggle with uncomfortable wind speeds. The aim of this study is to
investigate the role of sidewalk walls on pedestrian wind comfort. These multifunctional walls not only serve as street furniture,
but also reduce wind speed at pedestrian level. In this work, all simulations are performed using the RWIND tool and validated
by wind tunnel experiments at the Architectural Institute of Japan. The main objective of this study is to evaluate the effects of
the angle, height and spacing of the walls on wind attenuation at pedestrian level. The results show the effect of multifunctional
walls on pedestrian-level wind mitigation. By rotating the windbreak walls from 0 to 60 degrees along the street, the average
wind speed decreases by 30% to 46% compared to a situation without this type of wall. Increasing the wall height from 1.5 to 2
meters reduces the urban wind speed by 39-46%. However, increasing the distance between the sidewalk walls from 3.5-9.5
meters reduces the speed in the models from 46% to 32.7%. Finally, it has been demonstrated that sidewalk walls with a height
of 2 meters, a rotation angle of 60°and a distance of 3.5 meters are the optimal choice for wind attenuation at pedestrian level.
Address
Parinaz Badamchizadeh:Department of Geography and Urban Planning, Faculty of Planning and Environmental Sciences, University of Tabriz, 29 Bahman Blvd., Tabriz, Iran
Paria Saadatjoo:Department of Architecture, Faculty of Civil Engineering, University of Tabriz, 29 Bahman Blvd., Tabriz, Iran
Majid Ahmadlouydarab:Department of Chemical & Petroleum Engineering, University of Tabriz, 29 Bahman Blvd., Tabriz, Iran
