Using computational fluid dynamics to improve the drag coefficient estimates for tall buildings under wind loading

2017 ◽  
Vol 27 (3) ◽  
pp. e1442 ◽  
Author(s):  
Alexandre de Macêdo Wahrhaftig ◽  
Marcelo Araujo da Silva
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Coefficient ◽  
Tall Buildings ◽  
Wind Loading ◽  
Coefficient Estimates

Nonlinear spectral dynamic analysis of guyed towers. Part II: Manitoba towers case study

2004 ◽  
Vol 31 (6) ◽  
pp. 1061-1076 ◽  
Author(s):  
A M Horr ◽  
A Yibulayin ◽  
P Disney
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Complex Geometry ◽  
Spectral Element ◽  
Wind Loading ◽  
Space Structures ◽  
Loading Test ◽  
Large Space ◽  
Post Buckling ◽  
Guyed Towers

Dynamic response of large complex space structures under wind loading is important in terms of performance and safety. Conventional method of wind loading calculation has been used successfully in codes to analyze large space structures. The method can be applied by approximating the air pressure, induced by wind, on the surfaces of structures. Although this replaces a wind loading test using complicated wind tunnel tests for any structural systems, the accuracy of the method, in the case of complex geometry guyed tower structures, is a matter of consideration. Hence, it is desirable to search for a procedure with more accuracy and reliability. In this respect, attention is paid to the advanced spectral element method and the computational fluid dynamics. Using the proposed formulation, a material and geometric nonlinear dynamic analyses have been performed to simulate post-buckling behaviours and also collapse modes for series of Manitoba Hydro's guyed towers under extreme wind loading conditions. Key words: computational fluid dynamics, wind loading, collapse mode, nonlinear analysis, post-buckling.

Parametric Numerical Simulation of Mean Wind Loading on Stadium Cantilevered Roofs

2011 ◽  
Vol 243-249 ◽  
pp. 989-994
Author(s):  
Ying Sun ◽  
Bo Xiang ◽  
Bin Lin ◽  
Yue Wu
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Empirical Equation ◽  
Ventilation Rate ◽  
Wind Loading ◽  
Incoming Flow ◽  
Wind Force ◽  
Roof Structure ◽  
The Mean

Studies on the characteristics of the mean wind load acting on the cantilevered roofs are carried out systematically by CFD (Computational Fluid Dynamics) numerical simulation. The influences of some factors, including the incoming flow condition, inclination angle of roofs and the ventilation rate above grandstand, on mean wind loading are investigated. It is found that the terrain type and grandstand type are not significantly influence the mean wind loads on the roof structure; The wind force acting on roof is increased with roof pitch; Sub-roof venting is found to reduce uplifts by no more than 12%; Introducing a similar shaped grandstand upstream is found to significantly decrease the wind loading. Based on these results, an empirical equation for the calculation of mean wind loading is derived for the reference of designers.

Drag Reduction of Tractor-Trailers Using Optimized Add-On Devices

2010 ◽  
Vol 132 (8) ◽  
Author(s):  
Fu-Hung Hsu ◽  
Roger L. Davis
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Coefficient ◽  
Body Shape ◽  
Bluff Body ◽  
Navier Stokes ◽  
Optimized Design ◽  
Design Strategies ◽  
Body Design ◽  
Previous Idea

Tractor-trailers have a higher drag coefficient than other vehicles due to their bluff-body shape. Numerous add-on devices have been invented to help reduce drag and fuel consumption. The current research extends our previous idea of add-on humps and investigates their effect in conjunction with curved boat-tail flaps. Computational fluid dynamics in the form of unsteady Reynolds-averaged Navier–Stokes and detached-eddy simulations were used to determine viable design strategies. A 3D baseline computational model was constructed using an Ahmed body. Design optimization was applied on the new add-on devices. The results from the optimized design were shown to have a 50.9% reduction in drag coefficient.

scholarly journals STUDY OF MESH REFINEMENT ON THE AERODYNAMIC COEFFICIENTS FOR NACA2412 PROFILE WITH DIFFERENT ANGLE OF ATTACK AND k - w TURBULENCE MODEL

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Nícolas Lima Oliveira ◽  
Eric Vargas Loureiro ◽  
Patrícia Habib Hallak
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Coefficient ◽  
Turbulence Model ◽  
Lift Coefficient ◽  
Mesh Refinement ◽  
Angle Of Attack ◽  
Aerodynamic Coefficients ◽  
Computational Fluid Dynamics Cfd

This work presents the studies  obtained using OpenFOAM OpenSource Computational Fluid Dynamics (CFD) Software. Experiments were performed to predict lift coefficient and drag coefficient curves for the NACA2412 profile. Subsequently, the results obtained were compared with the results of the bibliography and discussed.

scholarly journals CFD Investigations of the Effect of Rotating Wheels, Ride Height and Wheelhouse Geometry on the Drag Coefficient of Electric Vehicle

2020 ◽  
Vol 14 ◽  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Coefficient ◽  
Electric Vehicles ◽  
Aerodynamic Drag ◽  
Design Parameters ◽  
Ride Height ◽  
Full Vehicle ◽  
Maximum Range ◽  
Computational Fluid Dynamics Cfd

The development of electric vehicles demands minimizing aerodynamic drag in order to provide maximum range. The wheels contribute significantly to overall drag coefficient value because of flow separation from rims and wheel arches. In this paper various design parameters are investigated and their influence on vehicle drag coefficient is presented. The investigation has been done with the help of computational fluid dynamics (CFD) tools and with implementation of full vehicle setup with rotating wheels. The obtained results demonstrate changes in drag coefficient with respect to the change of design parameters.

Aerodynamic Analysis of a Vehicle Tanker

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Ramon Miralbes Buil ◽  
Luis Castejon Herrer
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Coefficient ◽  
Aerodynamic Drag ◽  
Positive Impact ◽  
Aerodynamic Resistance ◽  
Independent Contribution ◽  
Aerodynamic Drag Coefficient ◽  
Computational Fluid Dynamics Cfd ◽  
Selection Of

The aim of this article is the presentation of a series of aerodynamic improvements for semitrailer tankers, which reduce the aerodynamic resistance of these vehicles, and, consequently, result in a positive impact on fuel consumption, which is substantially reduced (up to 11%). To make the analysis the computational fluid dynamics (CFD) methodology, using FLUENT, has been used since it allows simulating some geometries and modifications of the geometry without making physical prototypes that considerably increase the time and the economical resources needed. Three improvements are studied: the aerodynamic front, the undercarriage skirt, and the final box adaptor. First they are studied in isolation, so that the independent contribution of each improvement can be appreciated, while helping in the selection of the most convenient one. With the aerodynamic front the drag coefficient has a reduction of 6.13%, with the underskirt 9.6%, and with the boat tail 7.72%. Finally, all the improvements are jointly examined, resulting in a decrease of up to 23% in aerodynamic drag coefficient.

scholarly journals Hydrodynamic Analysis of Different Finger Positions in Swimming: A Computational Fluid Dynamics Approach

2015 ◽  
Vol 31 (1) ◽  
pp. 48-55 ◽  
Author(s):  
J. Paulo Vilas-Boas ◽  
Rui J. Ramos ◽  
Ricardo J. Fernandes ◽  
António J. Silva ◽  
Abel I. Rouboa ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Coefficient ◽  
Hydrodynamic Force ◽  
Lift Coefficient ◽  
Flow Speed ◽  
Cfd Analysis ◽  
Mean Flow ◽  
Hydrodynamic Analysis ◽  
Computational Fluid Dynamics Cfd

The aim of this research was to numerically clarify the effect of finger spreading and thumb abduction on the hydrodynamic force generated by the hand and forearm during swimming. A computational fluid dynamics (CFD) analysis of a realistic hand and forearm model obtained using a computer tomography scanner was conducted. A mean flow speed of 2 m·s−1was used to analyze the possible combinations of three finger positions (grouped, partially spread, totally spread), three thumb positions (adducted, partially abducted, totally abducted), three angles of attack (a = 0°, 45°, 90°), and four sweepback angles (y = 0°, 90°, 180°, 270°) to yield a total of 108 simulated situations. The values of the drag coefficient were observed to increase with the angle of attack for all sweepback angles and finger and thumb positions. For y = 0° and 180°, the model with the thumb adducted and with the little finger spread presented higher drag coefficient values for a = 45° and 90°. Lift coefficient values were observed to be very low at a = 0° and 90° for all of the sweepback angles and finger and thumb positions studied, although very similar values are obtained at a = 45°. For y = 0° and 180°, the effect of finger and thumb positions appears to be much most distinct, indicating that having the thumb slightly abducted and the fingers grouped is a preferable position at y = 180°, whereas at y = 0°, having the thumb adducted and fingers slightly spread yielded higher lift values. Results show that finger and thumb positioning in swimming is a determinant of the propulsive force produced during swimming; indeed, this force is dependent on the direction of the flow over the hand and forearm, which changes across the arm’s stroke.

scholarly journals Comparative Study on the Evaluation of Wind Load on Buildings Using Computational Fluid Dynamics and IS: 875(Part-3)

2018 ◽  
Vol 7 (1) ◽  
pp. 16-18
Author(s):  
J. Ashok ◽  
Shirlin Charles ◽  
C. Umarani
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cross Sections ◽  
Incidence Angle ◽  
Weighted Average ◽  
Tall Buildings ◽  
Wind Load ◽  
Wind Pressure ◽  
Lateral Loads ◽  
Ansys Fluent

Tall Buildings are highly susceptible to wind induced lateral loads and is required to be designed with greater accuracy. The codal provision IS 875 (part 3) which is usually used, has a limitation that the coefficient of pressure Cpvalues available are, only for 0 and 90 degrees wind incidence angles and for standard cross sections of buildings only. Therefore wind tunnel experiments are carried out to measure wind loads which provide reliable results than the code. This Paper deals with, computational fluid dynamics, an alternative and highly dependable tool to predict the wind related phenomena on buildings. A numerical evaluation of wind pressure is done for the different cases of buildings in IS 875 part-3. Wind load obtained by using IS 875 part-3 are compared with the result obtained from CFD in ANSYS Fluent 15.0 and results are found to be in good agreement .The mean area weighted average values of Coefficient of pressure are also computed for various wind incidence angle.

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