Numerical Simulation of the Disturbed Flow Through a Three-Dimensional Building Array
Numerical Simulation of the Disturbed Flow Through a Three-Dimensional Building Array

Author:

Publisher:

Published: 2004

Total Pages: 0

ISBN-13:

DOWNLOAD EBOOK

A study of the neutrally-stratified flow within and over an array of three-dimensional (3-D) buildings (cubes) was undertaken using simple Reynolds-averaged Navier-Stokes (RANS) flow models. These models consist of a general solution of the ensemble-averaged, steady-state, three-dimensional Navier-Stokes equations, where the k-E turbulence model (k is turbulence kinetic energy and E is viscous dissipation rate) has been used to close the system of equations. Two turbulence closure models were tested; namely, the standard and Kato-Launder k-E models. The latter model is a modified k-E model designed specifically to overcome the stagnation point anomaly in flows past a bluff body where the standard k-E model overpredicts the production of turbulence kinetic energy near the stagnation point. Results of a detailed comparison between a wind tunnel experiment and the RANS flow model predictions are presented. More specifically, vertical profiles of the predicted mean streamwise velocity, mean vertical velocity, and turbulence kinetic energy at a number of streamwise locations that extend from the impingement zone upstream of the array, through the array interior, to the exit region downstream of the array are presented and compared to those measured in the wind tunnel experiment. Generally, the numerical predictions show good agreement for the mean flow velocities. The turbulence kinetic energy was underestimated by the two different closure models. After validation, the results of the high-resolution RANS flow model predictions were used to diagnose the dispersive stress, within and above the building array. The importance of dispersive stresses, which arise from point-to-point variations in the mean flow field, relative to the spatially-averaged Reynolds stresses are assessed for the building array.

Numerical Simulation of Wind Forces on Structures
Numerical Simulation of Wind Forces on Structures

Author:

Publisher:

Published: 1978

Total Pages:

ISBN-13:

DOWNLOAD EBOOK

The use of numerical methods to predict wind loads on structures is explored. It is concluded that useful engineering results can be obtained numerically, at reasonable cost, for many different problems. However, it is also shown that a considerable amount of new methodology is needed before numerical methods can be of general utility for wind engineering purposes. These conclusions are based on studies performed with a simple numerical solution algorithm for the time-dependent, three-dimensional, Navier-Stokes equations. Calculational results are presented for a variety of simple structures subjected to uniform and boundary layer type winds. In each example the computer results are compared with wind tunnel data.

Computational Wind Engineering 1
Computational Wind Engineering 1

Author: S. Murakami

Publisher: Elsevier

Published: 2014-06-28

Total Pages: 925

ISBN-13: 0444598618

DOWNLOAD EBOOK

The aim of this volume is to explore the challenges posed by the rapid development of Computational Fluid Dynamics (CFD) within the field of engineering. CFD is already essential to research concerned with fluid flow in civil engineering, and its further potential for application in wind engineering is highly promising. State-of-the-art papers from all over the world are contained here, illuminating the present parameters of the field, as well as suggesting fruitful areas for further research. Eleven papers have been contributed by invited speakers outstanding in the fields of CFD and wind engineering. This volume will serve as a vehicle to promote further development in computational wind engineering.

Numerical Simulation of the Wind Flow Around a Tall Building and Its Dynamic Response to Wind Excitation
Numerical Simulation of the Wind Flow Around a Tall Building and Its Dynamic Response to Wind Excitation

Author: Julia Revuz

Publisher:

Published: 2011

Total Pages:

ISBN-13:

DOWNLOAD EBOOK

Wind action is particularly important for tall buildings, both in providing a signifi- cant contribution to the dynamic overall loading on the structure and by 'affecting its serviceability. Whereas low and medium-rise buildings are fairly rigid, tall structures are characterized by a greater flexibility and a lower natural frequency, which is more likely to be in the frequency range of wind gusts. In addition, wake effects, such as vor- tex shedding, can become a significant problem for flexible structures when the vortex shedding frequency is close to the natural frequency of the building. The aim of the present thesis is to assess the validity of commercial CFD codes for modelling the wind flow around a high-rise building, including the consideration of the coupled dynamic response of the building to turbulent wind loading. Three intermediate objectives are set. The first is to develop a tool to couple fluid and structure in a sequential manner. The equations for the air flow are solved using the commercial CFD program ANSYS- Fluent. The response of the structure is found from solving the structural response with a modal approach, the response in each vibration mode being treated as a SDOF problem. This fluid-structure interaction tool is applied to model a 180 m building, allowed to move in the across wind direction. The second objective is to investigate and find a method to generate fully turbulent inflow for LES in order to reproduce an accurate wind spectrum. The chosen method is tested and validated in an empty fetch. Ultimately, both tools are brought together and applied to model a 180 m building, which is allowed to bend in the along wind and across wind directions. Finally, the third intermediate objective brings together the tools developed in the first and second intermediate objective to model the dynamic response of a 180 m building to dynamic wind loading, within a turbulent inflow, using LES.

Environmental Wind Engineering and Design of Wind Energy Structures
Environmental Wind Engineering and Design of Wind Energy Structures

Author: Charalambos Baniotopoulos

Publisher: Springer Science & Business Media

Published: 2011-12-01

Total Pages: 353

ISBN-13: 3709109531

DOWNLOAD EBOOK

The book presents a state-of-the-art in environmental aerodynamics and the structural design of wind energy support structures, particularly from a modern computational perspective. Examples include real-life applications dealing with pollutant dispersion in the building environment, pedestrian-level winds, comfort levels, relevant legislation and remedial measures. Design methodologies for wind energy structures include reliability assessment and code frameworks.