Aerodynamic characteristics of rectangular cylinders in steady and accelerating wind flow

2019 ◽  
Vol 90 ◽  
pp. 246-262 ◽  
Author(s):  
Ting Yang ◽  
Matthew S. Mason
Keyword(s):  
Aerodynamic Characteristics ◽  
Wind Flow ◽  
Rectangular Cylinders

scholarly journals CFD MODELING OF AERODYNAMIC FLOW IN A WIND TURBINE WITH VERTICAL ROTATIONAL AXIS AND WIND FLOW CONCENTRATOR

2021 ◽  
pp. 159-166
Author(s):  
Valerii Gorobets ◽  
Viktor Trokhaniak ◽  
Mykola Masiuk ◽  
Nadiia Spodyniuk ◽  
Oleg Blesnyuk ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Three Dimensional ◽  
Vertical Axis ◽  
Aerodynamic Characteristics ◽  
Cfd Modeling ◽  
Wind Flow ◽  
Rotational Axis ◽  
Special Device ◽  
Vertical Axis Wind Turbine ◽  
Wind Flows

In order to improve the aerodynamic characteristics by increasing the energy of the wind flow of wind turbines with a vertical rotational axis, a special device - wind flow concentrator was proposed. The concentrator contains channels with a curved contour, which are installed around the rotor. To study the hydrodynamic parameters of the wind flows concentrator depending on the ratio between the input and output geometric characteristics of the channels, as well as the angles of entry and exit methods of mathematical modeling are used. Based on the method of quadratic rotational design of orthogonal combinations, using three-dimensional numerical simulation, the aerodynamic characteristics of the wind flow concentrator for a vertical axis wind turbine were investigated.

scholarly journals Unsteady RANS Modeling of Flow around Two-Dimensional Rectangular Cylinders with Different Side Ratios at Reynolds Number 6.85 × 105

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Shubiao Wang ◽  
Wenming Cheng ◽  
Run Du ◽  
Yupu Wang
Keyword(s):  
Reynolds Number ◽  
Numerical Study ◽  
Turbulence Models ◽  
Aerodynamic Characteristics ◽  
Navier Stokes ◽  
Bluff Bodies ◽  
Two Dimensional ◽  
Practical Engineering ◽  
Unsteady Rans ◽  
Rectangular Cylinders

In practical engineering, the Reynolds number (Re) of box girder structure is usually very high (Re ≥ 105), while most investigations of the flow around bluff bodies are concentrated on relatively lower Reynolds numbers (i.e., Re = 103–104). This paper presented a numerical study of the unsteady flow around two-dimensional rectangular cylinders under a Reynolds number of 6.85 × 105 with different side ratios (R = b/h, width to height) ranging from 0.1 to 4.0. Three unsteady Reynolds-averaged Navier-Stokes (RANS) two-equation k-ε turbulence models (standard, RNG, and realizable) were adopted in the study. The realizable k-ε model was chosen because it was found to perform the best among three models in the main aerodynamic integral parameters. According to the distinctions of aerodynamic characteristics with different side ratios, three regimes were divided and discussed in detail. The distribution of surface pressure over cylinders, the wake parameters, and vorticity contours of the rectangular cylinders with different side ratios were discussed.

Mathematical Model for Calculating Aerodynamic Characteristics of Overhead Transmission Lines

2014 ◽  
Vol 610 ◽  
pp. 52-59 ◽  
Author(s):  
Nurmakhan Tokenov ◽  
Muratkali Dzhamanbayev ◽  
Amangeldi Bekbayev ◽  
Damelya Eskendirova ◽  
Olimzhon Baimuratov
Keyword(s):  
Mathematical Model ◽  
Comparative Analysis ◽  
Mathematical Models ◽  
Transmission Lines ◽  
Numerical Experiments ◽  
Aerodynamic Characteristics ◽  
Physical Parameters ◽  
Wind Flow ◽  
Overhead Transmission Lines ◽  
Natural Factors

This article is devoted to creation of mathematical models of overhead transmission lines (OHTL), taking into account the glaze. In the studying and designing of transmission lines is often necessary to construct mathematical model taking into account the influence of natural factors and all the basic physical parameters affecting or hindering them. The main difficulties arise when describing the equation of oscillations, as they nonlinear. Numerical experiments and comparative analysis with previously reported models was presented. The main setting is the critical velocity of the wind flow and its dependence on the angle of attack to OHTL.

Aerodynamic Characteristics of Rectangular Cylinders

1999 ◽  
Vol 12 (2) ◽  
pp. 151-163 ◽  
Author(s):  
H. HIRANO ◽  
S. WATANABE ◽  
A. MARUOKA ◽  
M. IKENOUCHI
Keyword(s):  
Aerodynamic Characteristics ◽  
Rectangular Cylinders

scholarly journals The aerodynamics of the wavy blade under the effect of fluctuated wind flow

2021 ◽  
Vol 49 (3) ◽  
pp. 704-710
Author(s):  
Basim Al-Bakri ◽  
Radwan Aljuhashy
Keyword(s):  
Experimental Data ◽  
Unsteady Flow ◽  
Lift Coefficient ◽  
Leading Edge ◽  
Aerodynamic Characteristics ◽  
Wind Flow ◽  
Flow Conditions ◽  
Ansys Fluent ◽  
Turbulent Wind ◽  
Flow Case

In the present study, the influence of the wavy edge blade on aerodynamic characteristics for the flow of blades at Reynolds number (Re) of 8×105 is numerically investigated based on the unsteady wind flow. Aerodynamic characteristics of a (sinusoidal leading edge) wavy NACA0015 aerofoil blade are carried out using ICEM 19.1 and ANSYS fluent. The numerical simulation is conducted then validated by experimental data with steady wind flow. This is conducted by employing the same Reynold's number in the experimental work. While, the unsteady flow was numerically performed at 1 Hz frequency of wind flow conditions. The main findings from this work show that the wavy blade can behave better in turbulent wind conditions with the maximum lift coefficient of 0.73 compared to 0.621 for the normal blade. However, the findings declare that the wavy blade stalled earlier than the normal one in the unsteady flow case. Similarly, it stalled at 12° angle of attack earlier than the normal one which was stalled at 14° in the steady flow case.

scholarly journals Aerodynamic Characteristics Evaluation of a Cable-Stayed Bridge Section with a New-Type Hybrid Fairing

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Hoyeop Lee ◽  
Jiho Moon
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Wind Flow ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Aerodynamic Performances ◽  
New Type ◽  
Test Result

In this study, new-type hybrid faring is suggested to improve the aerodynamic performance of the long-span cable-stayed bridge. The proposed fairing is developed by applying the concept of the multibox section to the normal faring. The proposed faring has void regions inside the faring so that wind passes through the gaps in the faring. As a result, the wind flow is changed and the forces to the bridge section are reduced. The efficiency of the proposed faring was verified by a series of wind tunnel test. From the test result, it can be found that aerodynamic performances, such as drag force and flutter resistance, are enhanced.

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