An experimental study on dynamic ice accretion and its effects on the aerodynamic characteristics of stay cables with and without helical fillets

2021 ◽

Vol XLIII-B2-2021 ◽

pp. 527-532

Author(s):

V. A. Knyaz ◽

E. V. Ippolitov ◽

M. M. Novikov

Keyword(s):

Experimental Study ◽

Aerodynamic Characteristics ◽

Physical Models ◽

Accurate Information ◽

Ice Accretion ◽

Aircraft Icing ◽

Thermal Range ◽

Quantitative Understanding ◽

Behaviour Study ◽

Different Levels

Abstract. Aircraft icing is one of the main factors decreasing the flight safety. Qualitative and quantitative understanding of the icing process is crucially needed for developing anti-icing measures and safety recommendations. Changes in aerodynamic characteristics of aircraft caused by changes in shape of aircraft surfaces due to the ice accretion can lead to significant aerodynamic performance degradation. So the reliable and accurate information of how the shape of the ice accretion influences on aerodynamic characteristics is a key point for predicting the changes in aerodynamic performance.The study addresses to a problem of accurate shape measuring of ice accretion for further experimental study of iced-aircraft aerodynamic in a hydrodynamic tunnel. For this purpose the evaluation of various techniques of ice 3D measurements is performed that include as visible so thermal imaging of ice accretion. The results of evaluation serves for the decision of preferable technique to be used in experimental study. Also the framework is developed for creating physical models of iced aircraft based on result of real ice accretion shape measurement. It allows to produce stereolithography (SLA) copies of of an aircraft under icing condition for different levels of icing. These SLA-models of an aircraft under icing condition are then used for flow behaviour study in order to identify critical flying condition.

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Wind-Induced Response of Inclined and Yawed Ice-Accreted Stay Cable Models

Shock and Vibration ◽

10.1155/2018/6853047 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Songyu Cao ◽

Himan Hojat Jalali ◽

Elena Dragomirescu

Keyword(s):

Aerodynamic Drag ◽

Reynolds Numbers ◽

Aerodynamic Characteristics ◽

Induced Response ◽

Ice Accretion ◽

Stay Cable ◽

Cfd Simulations ◽

Stay Cables ◽

Inclination Angles ◽

Drag And Lift

During the past decades, wind-induced vibrations of bridge stay cables were reported to occur under various incipient conditions. The ice formation on stay cables is one of these conditions, which causes the ice-accreted stay cables to alter their cross section geometry, thus modifying their aerodynamic characteristics. Wind tunnel tests and several CFD simulations were performed for ice-accreted inclined bridge stay cables with two ice-accretion profiles dimensions, 0.5D and 1D, where D is the diameter of the cable. Wind-induced vibrations were analyzed experimentally for cable models with yaw inclination angles of 0°, 30°, and 60° and vertical inclination angles of 0° and 15°, for Reynolds numbers of up to 4 × 105. The aerodynamic drag and lift coefficients of the cable models and the pressure coefficients were determined from the CFD-LES simulations. The experimental results indicated that the vertical and torsional vibrations of the ice-accreted stay cables increased with the increase of the vertical and yaw angles. Also, higher vertical and torsional vibration amplitudes were measured for the case with larger ice thickness, indicating the effect of the ice accretion profile on the cable wind-induced response.

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Experimental Study of Fatigue Performance of Stay Cable Damper

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.487.404 ◽

2014 ◽

Vol 487 ◽

pp. 404-407

Author(s):

Dong Liang ◽

Zi Shuo Li

Keyword(s):

Experimental Study ◽

Good Condition ◽

Experimental Results ◽

Test Results ◽

Stay Cable ◽

Damping Force ◽

Durability Test ◽

Equivalent Damping ◽

Stay Cables ◽

Performance Deterioration

Oil dampers are widely used as a popular countermeasure to mitigate the stay cables vibration. In this study, one actual oil damper designed for some long cable-stayed was experimentally investigated to evaluate the durability. 4 million cycles loading, with frequency of 4 Hz and amplitude of 1 mm, was imposed on the damper. The excitation displacement and damping force were measured and the equivalent damping was calculated from the experimental results. The stiffness effects of dampers behaved during durability tests were also analyzed quantitatively. The test results showed that the dampers were still in good condition after 4 million cycles loading and the dampers temperatures were stable at 50 degree centigrade during the test. According to the durability test results, a model for performance deterioration of damper was proposed to predict the lifetime of oil dampers.

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