A Wind Tunnel Investigation Of Aerodynamic Loads On A Typical Tension Leg Platform

1986 ◽  
Author(s):  
A. Kareem ◽  
P.C. Lu ◽  
T.D. Finnigan ◽  
S.-L.V. Liu
Keyword(s):  
Wind Tunnel ◽  
Tension Leg Platform ◽  
Aerodynamic Loads

scholarly journals Influence of Embankments With Parapets on the Cross-Wind Turbulence Intensity at the Contact Wire of Railway Overheads

2010 ◽  
Author(s):  
Sergio Avila-Sanchez ◽  
Oscar Lopez-Garcia ◽  
Jose Meseguer
Keyword(s):  
Wind Tunnel ◽  
Environmental Factor ◽  
Turbulence Intensity ◽  
Experimental Analysis ◽  
System Operation ◽  
Contact Wire ◽  
Aerodynamic Loads ◽  
Essential Parameter ◽  
Railway System ◽  
Undamped Oscillations

Winds as an environmental factor can cause significant difficulties for the railway system operation. The railway overhead has been particularly vulnerable to cross-winds related problems, such as development of undamped oscillations due to galloping phenomenon. The installation of windbreaks to decrease the aerodynamic loads on the train can affect the loads on railway overheads triggering cable galloping. One essential parameter to indicate the influence of the parapet wake on the catenary contact wire is the turbulence intensity. In this paper the results of an experimental analysis of the turbulence intensity due to the presence of parapets carried out in a wind tunnel are reported. Embankments equipped with different parapets have been tested and turbulence intensity has been measured at both contact wire locations, windward and leeward. The relative influence of the parapets is measured through a reduced turbulence intensity, defined as the ratio between the turbulence intensity measured with parapet and the turbulence intensity in the case without any parapet on the embankment. In general the reduced turbulence intensity increases as the height of the parapet increases.

scholarly journals Wind Tunnel Analysis of the Aerodynamic Loads on Rolling Stock over Railway Embankments: The Effect of Shelter Windbreaks

2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Sergio Avila-Sanchez ◽  
Santiago Pindado ◽  
Oscar Lopez-Garcia ◽  
Angel Sanz-Andres
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Flow Characteristic ◽  
Rolling Stock ◽  
High Speed Train ◽  
Aerodynamic Loads ◽  
Common Solution ◽  
Small Height ◽  
Tunnel Analysis ◽  
Sheltering Effect

Wind-flow pattern over embankments involves an overexposure of the rolling stock travelling on them to wind loads. Windbreaks are a common solution for changing the flow characteristic in order to decrease unwanted effects induced by the presence of cross-wind. The shelter effectiveness of a set of windbreaks placed over a railway twin-track embankment is experimentally analysed. A set of two-dimensional wind tunnel tests are undertaken and results corresponding to pressure tap measurements over a section of a typical high-speed train are herein presented. The results indicate that even small-height windbreaks provide sheltering effects to the vehicles. Also, eaves located at the windbreak tips seem to improve their sheltering effect.

Investigation of Spatial Coherences of Aerodynamic Loads on a Streamlined Bridge Deck in an Actively-Controlled Wind Tunnel

2014 ◽  
Vol 17 (1) ◽  
pp. 53-65 ◽  
Author(s):  
Kun Xu ◽  
Lin Zhao ◽  
Shu-Yang Cao ◽  
Akihito Yoshida ◽  
Yukio Tamura ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Bridge Deck ◽  
Aerodynamic Loads

scholarly journals Development of a morphing wingtip based on compliant structures

2018 ◽  
Vol 29 (16) ◽  
pp. 3293-3304 ◽  
Author(s):  
Chen Wang ◽  
Hamed Haddad Khodaparast ◽  
Michael I Friswell ◽  
Alexander D Shaw ◽  
Yuying Xia ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Dihedral Angle ◽  
Honeycomb Structure ◽  
Equivalent Model ◽  
Morphing Aircraft ◽  
Aerodynamic Loads ◽  
Compliant Structure ◽  
Trailing Edges ◽  
Morphing Structure ◽  
Structural Solutions

Compliant structures, such as flexible corrugated panels and honeycomb structures, are promising structural solutions for morphing aircraft. The compliant structure can be tailored to carry aerodynamic loads and achieve the geometry change simultaneously, while the reliability of the morphing aircraft can be guaranteed if conventional components and materials are used in the fabrication of the morphing structure. In this article, a compliant structure is proposed to change the dihedral angle of a morphing wingtip. Unsymmetrical stiffness is introduced in the compliant structure to induce the rotation of the structure. Trapezoidal corrugated panels are used, whose geometry parameters can be tailored to provide the stiffness asymmetry. An equivalent model of the corrugated panel is employed to calculate the deformation of the compliant structure. To provide the airfoil shape, a flexible honeycomb structure is used in the leading and trailing edges. An optimisation is performed to determine the geometry variables, while also considering the actuator requirements and the available space to instal the compliant structure. An experimental prototype has been manufactured to demonstrate the deformation of the morphing wingtip and conduct basic wind tunnel tests.

A Three-Component, Strain-Gauged Sting Balance for Use in Small Low-Speed Wind Tunnels

1966 ◽  
Vol 70 (670) ◽  
pp. 951-952 ◽  
Author(s):  
J. A. C. Marsden
Keyword(s):  
Wind Tunnel ◽  
The Other ◽  
Wind Tunnels ◽  
List Type ◽  
Wind Tunnel Testing ◽  
Pitching Moment ◽  
Type Number ◽  
Aerodynamic Loads ◽  
Component Strain ◽  
Manufacturing Time

In preparation for the wind tunnel testing of a series of aerodynamic research models a strain-gauged balance was sought which could be successfully made without the use of sophisticated tools. The principal requirements which influenced the design of the balance were:(a)It must enable lift, drag and pitching moment to be measured.(b)Deformation of the balance under the aerodynamic loads to be small.(c)Use of only basic workshop tools.(d)Short manufacturing time.Further, the models were to be sting mounted at one end of the balance with their span vertical. The other end of the balance was to be rigidly fixed to a supporting stand which would be mounted on the wind tunnel turntable to permit incidence variation (Fig. 5).

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