scholarly journals Experimental Study of Aerodynamic Interference Effects for a Suspended Monorail Vehicle–Bridge System Using a Wireless Acquisition System

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5841
Author(s):  
Yunfeng Zou ◽  
Zhipeng Liu ◽  
Kang Shi ◽  
Shuangmei Ou ◽  
Xuhui He ◽  
...  

The suspended monorail (SM) vehicle–bridge system has been considered a promising modern transit mode due to its clear advantages: low pollution, high safety, convenient construction, and low cost. The wind-induced response can significantly affect the running safety and comfort of this type of vehicle due to its special suspended position from a fixed track. This study is the first to systematically investigate its aerodynamic characteristics and interference effects under various spacing ratios using wind tunnel tests and numerical simulations. A high level of agreement between the wind tunnel test and CFD (computational fluid dynamics) results was obtained, and the aerodynamic interference mechanism can be well explained using the CFD technique from a flow field perspective. A wireless wind pressure acquisition system is proposed to achieve synchronization acquisition for multi wind pressure test taps. The paper confirms that (1) the proposed wireless wind pressure acquisition system performed well; (2) the aerodynamic coefficients of the upstream vehicle and bridge were nearly unchanged for vehicle–bridge combinations with varying spacing ratios; (3) the aerodynamic interference effects were amplified when two vehicles meet, but the effects decrease as the spacing ratio increases; (4) the aerodynamic force coefficients, mean, and root mean square (RMS) wind pressure coefficients for the downstream vehicle and bridge are readily affected by the upstream vehicle; (5) the vortex shedding frequencies of vehicles and bridges can be readily obtained from the lift force spectra, and they decrease as the spacing ratio increases; and (6) a spacing ratio of 3.5 is suggested in the field applications to ensure the running safety and stability of the SM vehicle–bridge system under exposure to crosswinds.

2013 ◽  
Vol 12 (2) ◽  
pp. 079-086
Author(s):  
Grzegorz Bosak

The paper summarizes the results of wind tunnel tests of the influence of aerodynamic interference on wind action of a high-rise building design in Warsaw. Measurements were accomplished in Wind Engineering Laboratory of Cracow University of Technology. Wind pressures on external surfaces of the building model were acquired in two different situations. Firstly, only the building model was placed in the tunnel working section, secondly, the building model with the nearest surroundings was taken under consideration. A study of the character of wind action differences caused by the nearest surroundings of the building was the main aim of the paper. Wind pressure coefficients on the external building surfaces and the difference of horizontal wind action on full scale were compared.


2018 ◽  
Vol 18 (12) ◽  
pp. 1850156
Author(s):  
Yi Zhou ◽  
Yuanqi Li ◽  
Akihito Yoshida

Flexible roof structures, such as membranes, are sensitive to wind action due to their flexibility and light weight. Previously, the effect of added mass on the vibration frequency of membrane structures has been experimentally tested. However, the effect of added mass on wind-induced vibration remains unclear. The purpose of this paper is to investigate the effect of added mass on the wind-induced vibration of a circular flat membrane based on wind tunnel tests. First, wind tunnel tests were conducted to obtain wind pressure distribution from the rigid model and wind-induced vibration from the aeroelastic model of a circular flat membrane. Secondly, a dynamic finite element analysis for the proposed added mass model was conducted to obtain the wind-induced vibration of the membrane structure. Then, with the wind pressure distribution obtained from the rigid model tests, dynamic analysis was conducted either with or without consideration of the effect of added mass. According to the dynamic analysis results and the wind tunnel test results, it is clear that considering the effect of added mass in dynamic analysis can significantly improve the accuracy of a wind-induced response. Such an effect is more significant at the windward than the central zone. The inclusion of added mass can result in a larger displacement response as wind velocity increases but a smaller response as the prestress level increases.


2012 ◽  
Vol 178-181 ◽  
pp. 2131-2134
Author(s):  
Jie Wang ◽  
Jian Xin Liu

Against the problem of the aerodynamic interference effects on aerostatic coefficients between parallel continuous rigid frame bridges with high-pier and long-span, the aerodynamic interference effects on aerostatic coefficients of main beam in the parallel long-span continuous rigid frame bridges were investigated in details by means of wind tunnel test. The space between the two main beams and wind attack angles were changed during the wind tunnel test to study the effects on aerodynamic interferences of aerostatic coefficients of main beam. The test got aerostatic coefficients of 10 conditions. The research results have shown that the aerodynamic interference effects on aerostatic coefficients of main beam in parallel bridges can not be ignored. The aerodynamic interference effects on parallel bridge main beam is shown mainly as follows: The drag coefficient of main beam downstream dropped and the drag coefficient of main beam upstream changed but not change significantly. There are also the aerodynamic interference effects of lateral force coefficient and torque coefficient between the main beams upstream and downstream. The effects upstream are smaller and the effects downstream are larger.


2010 ◽  
Vol 163-167 ◽  
pp. 4280-4285
Author(s):  
Di Wu ◽  
Ying Sun ◽  
Yue Wu

Taking Harbin west railway station as the researching object, the wind load distribution as well as its effects, which are widely used in practice, is investigated. First, wind pressure distribution on a rigid model is measured simultaneously in a wind tunnel. Some special characteristics of the measured wind pressure, especially its fluctuating component, are discussed. Then the fluctuating wind pressure field is reconstructed based on the synchronous multi-pressure scanning technique of wind tunnel tests and the proper orthogonal decomposition (POD) technique. The influence of lower RC structure on wind-induced vibration is investigated using non-linear time-history analysis. At last, a new method is introduced to obtain equivalent static wind load (ESWL) that reproduce all largest load effects at the same time. With the synthetic application of above methods, the problems such as: complex time and spatial distribution of fluctuating wind; multi-mode vibration of wind-induced response; multiple equivalent objectives for ESWL, can be solved efficiently.


2011 ◽  
Vol 368-373 ◽  
pp. 1517-1520 ◽  
Author(s):  
Jie Wang ◽  
Jin Yun Zhao ◽  
Jian Xin Liu

Against the problem of the aerodynamic interference effects on aerostatic coefficients between parallel continuous rigid frame bridges with high-pier and long-span, the aerodynamic interference effects on aerostatic coefficients of double thin-walled hollow pier in the parallel long-span continuous rigid frame bridges were investigated in details by means of wind tunnel test.The space between the two piers and wind direction angles were changed during the wind tunnel test to study the effects on aerodynamic interferences of aerostatic coefficients of twin piers. The test got aerostatic coefficients of 8 conditions. The research results have shown that the aerodynamic interference effects on aerostatic coefficients of double thin-walled hollow pier in parallel bridges can not be ignored. The aerodynamic interference effects on parallel bridge pier is shown mainly as follows: The tandem interval and wind direction angles are important factors affecting interference effects. The drag coefficient of pier downstream dropped and the drag coefficient of pier upstream changed but Not change significantly. There are also the aerodynamic interference effects of lateral force coefficient and torque coefficient between the piers upstream and downstream. The effects upstream are smaller and the effects downstream are larger.


2013 ◽  
Vol 361-363 ◽  
pp. 1414-1417
Author(s):  
Jie Wang ◽  
Jian Xin Liu

In order to investigate the aerodynamic interference effects between parallel bridges, the aerodynamic interference effects on aerostatic coefficients of double thin-walled hollow pier in the parallel continuous rigid frame bridges with high-pier and long-span were investigated in details by means of wind tunnel test. The tandem interval and side-by-side interval between the two piers and wind direction angles were changed during the wind tunnel test to study the effects on aerodynamic interferences of aerostatic coefficients of twin piers. The test got aerostatic coefficients of 10 conditions. The research results have shown that the aerodynamic interference effects on aerostatic coefficients of double thin-walled hollow pier in parallel bridges can not be ignored. The tandem interval and side-by-side interval between the two piers and wind direction angles are important factors affecting interference effects. The drag coefficient, lateral force coefficient and torque coefficient are affected by these factors.


Author(s):  
Junji Maeda ◽  
Takashi Takeuchi ◽  
Eriko Tomokiyo ◽  
Yukio Tamura

To quantitatively investigate a gusty wind from the viewpoint of aerodynamic forces, a wind tunnel that can control the rise time of a step-function-like gust was devised and utilized. When the non-dimensional rise time, which is calculated using the rise time of the gusty wind, the wind speed, and the size of an object, is less than a certain value, the wind force is greater than under the corresponding steady wind. Therefore, this wind force is called the “overshoot wind force” for objects the size of orbital vehicles in an actual wind observation. The finding of the overshoot wind force requires a condition of the wind speed recording specification and depends on the object size and the gusty wind speed.


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