A Discussion of Aerodynamic Interference Effects Between a Race Car and a Race Track Retaining Wall (A Wind Tunnel NASCAR Case Study)

1988 ◽  
Author(s):  
S. B. Wallis ◽  
W. J. Quinlan
Keyword(s):  
Wind Tunnel ◽  
Retaining Wall ◽  
Interference Effects ◽  
Race Car ◽  
Race Track ◽  
Aerodynamic Interference

Test Research on Aerodynamic Interference Effect on Aerostatic Coefficients of Main Beam in Parallel Bridge

2012 ◽  
Vol 178-181 ◽  
pp. 2131-2134
Author(s):  
Jie Wang ◽  
Jian Xin Liu
Keyword(s):  
Wind Tunnel ◽  
Drag Coefficient ◽  
Wind Tunnel Test ◽  
Lateral Force ◽  
Main Beam ◽  
Interference Effects ◽  
Force Coefficient ◽  
Long Span ◽  
Rigid Frame ◽  
Aerodynamic Interference

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.

Experimental Study of Aerodynamic Interference Effects on Double Thin-Walled Hollow Pier in Tandem Arrangement

2011 ◽  
Vol 368-373 ◽  
pp. 1517-1520 ◽  
Author(s):  
Jie Wang ◽  
Jin Yun Zhao ◽  
Jian Xin Liu
Keyword(s):  
Wind Tunnel ◽  
Drag Coefficient ◽  
Wind Direction ◽  
Wind Tunnel Test ◽  
Interference Effects ◽  
Force Coefficient ◽  
Long Span ◽  
Rigid Frame ◽  
Aerodynamic Interference ◽  
Thin Walled

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.

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 ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Aerodynamic Force ◽  
Wind Pressure ◽  
Acquisition System ◽  
Induced Response ◽  
Interference Effects ◽  
Running Safety ◽  
Spacing Ratio ◽  
Aerodynamic Interference ◽  
Bridge System

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.

Study of Aerodynamic Interference Effects on Staggered Double Thin-Walled Hollow Pier

2013 ◽  
Vol 361-363 ◽  
pp. 1414-1417
Author(s):  
Jie Wang ◽  
Jian Xin Liu
Keyword(s):  
Wind Tunnel ◽  
Wind Direction ◽  
Wind Tunnel Test ◽  
Lateral Force ◽  
Interference Effects ◽  
Force Coefficient ◽  
Factors Affecting ◽  
Rigid Frame ◽  
Aerodynamic Interference ◽  
Thin Walled

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.

Safety and reliability of retaining wall: case study

Geotecnia ◽  
2016 ◽  
Vol 138 ◽  
pp. 37-60
Author(s):  
Rinaldo Garcia Ramirez ◽  
◽  
Jeselay Hemetério Cordeiro dos Reis ◽  
Keyword(s):  
Retaining Wall ◽  
Safety And Reliability

Aerodynamic interference test of quad tilt rotor aircraft in wind tunnel

2019 ◽  
Vol 233 (15) ◽  
pp. 5553-5566 ◽  
Author(s):  
Kun Chen ◽  
Zhiwei Shi ◽  
Shengxiang Tong ◽  
Yizhang Dong ◽  
Jie Chen
Keyword(s):  
Wind Tunnel ◽  
Reference Value ◽  
Ground Effect ◽  
Open Loop ◽  
Force Balance ◽  
Scale Model ◽  
Operating Condition ◽  
Tilt Rotor ◽  
Interference Test ◽  
Aerodynamic Interference

There is an obvious aerodynamic interference problem that occurs for a quad tilt rotor in near-ground hovering or in the conversion operating condition. This paper presents an aerodynamic interference test of the quad tilt rotor in a wind tunnel. A 1:35 scale model of the quad tilt rotor is used in this test. To substitute for the ground, a moveable platform is designed in a low-speed open-loop wind tunnel to simulate different flight altitudes of the quad tilt rotor in hovering or forward flight. A rod six-component force balance is used to measure the loads on the aircraft, and the flow field below the airframe is captured using particle image velocimetry. The experimental results show that the ground effect is significant when the hover height above the ground is less than the rotor diameter of the quad tilt rotor aircraft, and the maximum upload of the airframe is approximately 12% of the total vertical thrust with the appearance of obvious fountain flow. During the conversion operating condition, the upload of the airframe is reduced compared with that in the hovering state, which is affected by rotor wake and incoming flow. The aerodynamic interference test results of the quad tilt rotor aircraft have important reference value in power system selection, control system design, and carrying capacity improvement with the advantage of ground effect.

scholarly journals Comparison of Typical Controllers for Direct Yaw Moment Control Applied on an Electric Race Car

Vehicles ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 127-144
Author(s):  
Andoni Medina ◽  
Guillermo Bistue ◽  
Angel Rubio
Keyword(s):  
Handling Performance ◽  
Electric Cars ◽  
Control Techniques ◽  
Race Car ◽  
Yaw Rate ◽  
Direct Yaw Moment Control ◽  
Yaw Moment Control ◽  
Moment Control ◽  
Race Track ◽  
Yaw Moment

Direct Yaw Moment Control (DYC) is an effective way to alter the behaviour of electric cars with independent drives. Controlling the torque applied to each wheel can improve the handling performance of a vehicle making it safer and faster on a race track. The state-of-the-art literature covers the comparison of various controllers (PID, LPV, LQR, SMC, etc.) using ISO manoeuvres. However, a more advanced comparison of the important characteristics of the controllers’ performance is lacking, such as the robustness of the controllers under changes in the vehicle model, steering behaviour, use of the friction circle, and, ultimately, lap time on a track. In this study, we have compared the controllers according to some of the aforementioned parameters on a modelled race car. Interestingly, best lap times are not provided by perfect neutral or close-to-neutral behaviour of the vehicle, but rather by allowing certain deviations from the target yaw rate. In addition, a modified Proportional Integral Derivative (PID) controller showed that its performance is comparable to other more complex control techniques such as Model Predictive Control (MPC).

scholarly journals Cable Suspension and Balance System with Low Support Interference and Vibration for Effective Wind Tunnel Tests

2021 ◽  
Author(s):  
Keum-Yong Park ◽  
Yeol-Hun Sung ◽  
Jae-Hung Han
Keyword(s):  
Wind Tunnel ◽  
Vibration Suppression ◽  
Aerodynamic Load ◽  
Test Model ◽  
Wind Tunnel Tests ◽  
Balance System ◽  
Motion Responses ◽  
Vibration Responses ◽  
Aerodynamic Interference ◽  
Support Interference

AbstractA cable-driven model support concept is suggested and implemented in this paper. In this case, it is a cable suspension and balance system (CSBS), which has the advantages of low support interference and reduced vibration responses for effective wind tunnel tests. This system is designed for both model motion control and aerodynamic load measurements. In the CSBS, the required position or the attitude of the test model is realized by eight motors, which adjust the length, velocity, and acceleration of the corresponding cables. Aerodynamic load measurements are accomplished by a cable balance consisting of eight load cells connected to the assigned cables. The motion responses and load measurement outputs were in good agreement with the reference data. The effectiveness of the CSBS against aerodynamic interference and vibration is experimentally demonstrated through comparative tests with a rear sting and a crescent sting support (CSS). The advantages of the CSBS are examined through several wind tunnel tests of a NACA0015 airfoil model. The cable support of the CSBS clearly showed less aerodynamic interference than the rear sting with a CSS, judging from the drag coefficient profile. Additionally, the CSBS showed excellent vibration suppression characteristics at all angles of attack.

scholarly journals Wind tunnel tests of aerodynamic interference of the high-rise building and its nearest city surroundings

2013 ◽  
Vol 12 (2) ◽  
pp. 079-086
Author(s):  
Grzegorz Bosak
Keyword(s):  
Wind Tunnel ◽  
Building Design ◽  
Wind Pressure ◽  
Horizontal Wind ◽  
Wind Tunnel Tests ◽  
Wind Action ◽  
Building Model ◽  
High Rise ◽  
High Rise Building ◽  
Aerodynamic Interference

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.

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