The changes of three components of aerodynamic force were discussed with the attack angle conversion for three kinds of section models.Based on the project of Shanghai Yangtze River Bridge,the wind tunnel test was con...The changes of three components of aerodynamic force were discussed with the attack angle conversion for three kinds of section models.Based on the project of Shanghai Yangtze River Bridge,the wind tunnel test was conducted to obtain its three components of aerodynamic force including 75 conditions of the construction stage,the bridge without vehicles and the bridge with vehicles from-12 degrees to +12 degrees.For the bridge with vehicles,the drag force coefficient and the absolute value of both lift coefficient and moment coefficient were decreased by the vehicles.The test result shows that the bridge railing and vehicles have much influence on the three components of aerodynamic force of the vehicle-bridge system for Shanghai Yangtze River Bridge.展开更多
The large dual-channel wide-bodied aircraft has a long range and a high cruise Mach number.Therefore,its aerodynamic design requires a high level ofwind tunnel test refinement.Based on the requirements of aerodynamic ...The large dual-channel wide-bodied aircraft has a long range and a high cruise Mach number.Therefore,its aerodynamic design requires a high level ofwind tunnel test refinement.Based on the requirements of aerodynamic design for the future wide-bodied aircraft and the characteristics of high-speed wind tunnel tests,the error theory is introduced to analyze the factors affecting the accuracy of the test data.This study carries out a series of research on the improvement of refined aerodynamic test technology in an FL-26 wind tunnel,including design and optimization of the support system of wide-bodied aircraft,model attitude angle measurement,Mach number control accuracy,measurement and control system stability,test data correction and perfection,high-precision force balance and standard model development.In addition,the effect of the standard specification of the refined aerodynamic test is investigated to improve the data quality.The research findings have been applied in the standard model test and subsequent models of wide-bodied aircraft.The results show that whenMach numbers are less than 0.9,the control accuracy of Mach numbers in the FL-26 wind tunnel is smaller than 0.001 and the measurement error of attack angle is smaller than 0.01°.Therefore,it has the ability to correct the data influenced by factors,such as support/wall interference,model deformation,floating resistance and airflow deflection angle.The repeatability accuracy of the standard model’s comparison test shows that the lift coefficient is less than or equal to 0.0012,the drag coefficient is less than or equal to 0.00004,pitching moment coefficient is less than or equal to 0.0004.The bending resolution of the model’s deformation measurement is less than 0.2 mm,and the tensional deformation is smaller than 0.04°.The revised aerodynamic data and model deformation measurement results have good agreement with that of the ETW wind tunnel.The results demonstrate that the improved technology presented in this paper can significantly enhance the refined aerodynamic test of wide-bodied aircraft.展开更多
Segment sectional model tests are carried out to investigate the wind loading on middle pylon of Taizhou Bridge, which has complicated three-dimensional flow due to its feature of double columns. Through the force mea...Segment sectional model tests are carried out to investigate the wind loading on middle pylon of Taizhou Bridge, which has complicated three-dimensional flow due to its feature of double columns. Through the force measuring tests, aerodynamic force coefficients of every segment of the pylon columns have been obtained. It is found that the tested aerodynamic force coefficients are much smaller than those given by codes. The interference effects of aerodynamic force coefficients between columns of pylon are discussed. The results show that the interference effect is the most evident when the yaw angle is about 30 ° from transverse direction. This kind of interference effect can be described as diminutions in transverse aerodynamic force coefficients and magnifications in longitudinal aerodynamic force coefficients of downstream columns.展开更多
Full aero-elastic model tests are carried out to investigate wind-induced vibration of middle steel pylon of Taizhou Bridge. Model of the pylon under different construction periods is tested in both uniform and turbul...Full aero-elastic model tests are carried out to investigate wind-induced vibration of middle steel pylon of Taizhou Bridge. Model of the pylon under different construction periods is tested in both uniform and turbulent flow field. And the yaw angle of wind changes from transverse to longitudinal. Through full aero-elastic model testing, wind-induced vibration is checked, which includes vortex resonance, buffeting and galloping. Vortex resonance is observed and further studies are carried out by changing damping ratio. Based on wind tunnel testing results, wind-resistance of middle pylon is evaluated and some suggestions are given for middle pylon's construction.展开更多
For the purpose of establishing and validating aerodynamic performance predictions at transonic Mach numbers, a wind tunnel test was conducted in the High-Speed Tunnel（HST） of the German-Dutch Wind Tunnels. The test...For the purpose of establishing and validating aerodynamic performance predictions at transonic Mach numbers, a wind tunnel test was conducted in the High-Speed Tunnel（HST） of the German-Dutch Wind Tunnels. The test article is the aerodynamic validation model from the Chinese Aeronautical Establishment, which is a full-span scale model representation of a business jet aircraft. The wind tunnel test comprised of parallel deployments of balance, pressures, infrared thermography, and model marker measurement techniques. Dedicated investigations with a dummy support were conducted as well, in order to derive and correct for the interference that the support system imposed on the overall model loads. This enabled the establishment of a comprehensive dataset in which the steady overall model loads, the wing load distribution, the state of the wing boundary layer, and the aeroelastic wing shape were quantified for conditions up to and beyond the cruise Mach number of 0.85.展开更多
It is necessary to study how vehicles influence the vortex-excited resonance of vehicle-bridge systems,because lock-in wind speed is low and vortex-excited resonance is sensitive to any change in the main girder secti...It is necessary to study how vehicles influence the vortex-excited resonance of vehicle-bridge systems,because lock-in wind speed is low and vortex-excited resonance is sensitive to any change in the main girder sections.Based on the Shanghai Bridge over the Yangtse River,the vortex-excited resonance of a 1∶60 scale sectional model was tested in a TJ-1wind tunnel,with or without vehicles at the attack angle of 0°,+3 and–3°,respectively.The conversion relationships between the resonant amplitudes of the sectional model and that of the prototype bridge were also established by mode shape correction.The result indicates that:1)for the bridge with vehicles,the vertical vortex-excited resonance is accompanied by torsion vibration with the same frequency,and vice versa,2)the amplitude of vortex-excited resonance of the bridge with vehicles is much larger than that of the bridge without vehicles,and 3)the lock-in wind speed of the vortex-excited resonance becomes smaller due to the disturbance of vehicles.It is obvious that vehicles bring about changes in the aerodynamic shape of the main girder.Therefore,the influence of vehicles on vortex-excited resonance performance of vehicle-bridge systems,in terms of both amplitude and mode,should not be ignored.展开更多
基金Sponsored by the Key Project of the National Natural Science Foundation of China (Grant No.90715039)
文摘The changes of three components of aerodynamic force were discussed with the attack angle conversion for three kinds of section models.Based on the project of Shanghai Yangtze River Bridge,the wind tunnel test was conducted to obtain its three components of aerodynamic force including 75 conditions of the construction stage,the bridge without vehicles and the bridge with vehicles from-12 degrees to +12 degrees.For the bridge with vehicles,the drag force coefficient and the absolute value of both lift coefficient and moment coefficient were decreased by the vehicles.The test result shows that the bridge railing and vehicles have much influence on the three components of aerodynamic force of the vehicle-bridge system for Shanghai Yangtze River Bridge.
文摘The large dual-channel wide-bodied aircraft has a long range and a high cruise Mach number.Therefore,its aerodynamic design requires a high level ofwind tunnel test refinement.Based on the requirements of aerodynamic design for the future wide-bodied aircraft and the characteristics of high-speed wind tunnel tests,the error theory is introduced to analyze the factors affecting the accuracy of the test data.This study carries out a series of research on the improvement of refined aerodynamic test technology in an FL-26 wind tunnel,including design and optimization of the support system of wide-bodied aircraft,model attitude angle measurement,Mach number control accuracy,measurement and control system stability,test data correction and perfection,high-precision force balance and standard model development.In addition,the effect of the standard specification of the refined aerodynamic test is investigated to improve the data quality.The research findings have been applied in the standard model test and subsequent models of wide-bodied aircraft.The results show that whenMach numbers are less than 0.9,the control accuracy of Mach numbers in the FL-26 wind tunnel is smaller than 0.001 and the measurement error of attack angle is smaller than 0.01°.Therefore,it has the ability to correct the data influenced by factors,such as support/wall interference,model deformation,floating resistance and airflow deflection angle.The repeatability accuracy of the standard model’s comparison test shows that the lift coefficient is less than or equal to 0.0012,the drag coefficient is less than or equal to 0.00004,pitching moment coefficient is less than or equal to 0.0004.The bending resolution of the model’s deformation measurement is less than 0.2 mm,and the tensional deformation is smaller than 0.04°.The revised aerodynamic data and model deformation measurement results have good agreement with that of the ETW wind tunnel.The results demonstrate that the improved technology presented in this paper can significantly enhance the refined aerodynamic test of wide-bodied aircraft.
基金National Science and Technology Support Program of China ( No. 2009BAG15B01)Key Pro-grams for Science and Technology Development of Chinese Transportation Industry ( No. 2008-353-332-190 )National Science Foundation( No. 51008233)
文摘Segment sectional model tests are carried out to investigate the wind loading on middle pylon of Taizhou Bridge, which has complicated three-dimensional flow due to its feature of double columns. Through the force measuring tests, aerodynamic force coefficients of every segment of the pylon columns have been obtained. It is found that the tested aerodynamic force coefficients are much smaller than those given by codes. The interference effects of aerodynamic force coefficients between columns of pylon are discussed. The results show that the interference effect is the most evident when the yaw angle is about 30 ° from transverse direction. This kind of interference effect can be described as diminutions in transverse aerodynamic force coefficients and magnifications in longitudinal aerodynamic force coefficients of downstream columns.
基金National Science and Technology Support Program of China(No.2009BAG15B01)National Science Foundation(No.51008233)
文摘Full aero-elastic model tests are carried out to investigate wind-induced vibration of middle steel pylon of Taizhou Bridge. Model of the pylon under different construction periods is tested in both uniform and turbulent flow field. And the yaw angle of wind changes from transverse to longitudinal. Through full aero-elastic model testing, wind-induced vibration is checked, which includes vortex resonance, buffeting and galloping. Vortex resonance is observed and further studies are carried out by changing damping ratio. Based on wind tunnel testing results, wind-resistance of middle pylon is evaluated and some suggestions are given for middle pylon's construction.
文摘For the purpose of establishing and validating aerodynamic performance predictions at transonic Mach numbers, a wind tunnel test was conducted in the High-Speed Tunnel（HST） of the German-Dutch Wind Tunnels. The test article is the aerodynamic validation model from the Chinese Aeronautical Establishment, which is a full-span scale model representation of a business jet aircraft. The wind tunnel test comprised of parallel deployments of balance, pressures, infrared thermography, and model marker measurement techniques. Dedicated investigations with a dummy support were conducted as well, in order to derive and correct for the interference that the support system imposed on the overall model loads. This enabled the establishment of a comprehensive dataset in which the steady overall model loads, the wing load distribution, the state of the wing boundary layer, and the aeroelastic wing shape were quantified for conditions up to and beyond the cruise Mach number of 0.85.
文摘It is necessary to study how vehicles influence the vortex-excited resonance of vehicle-bridge systems,because lock-in wind speed is low and vortex-excited resonance is sensitive to any change in the main girder sections.Based on the Shanghai Bridge over the Yangtse River,the vortex-excited resonance of a 1∶60 scale sectional model was tested in a TJ-1wind tunnel,with or without vehicles at the attack angle of 0°,+3 and–3°,respectively.The conversion relationships between the resonant amplitudes of the sectional model and that of the prototype bridge were also established by mode shape correction.The result indicates that:1)for the bridge with vehicles,the vertical vortex-excited resonance is accompanied by torsion vibration with the same frequency,and vice versa,2)the amplitude of vortex-excited resonance of the bridge with vehicles is much larger than that of the bridge without vehicles,and 3)the lock-in wind speed of the vortex-excited resonance becomes smaller due to the disturbance of vehicles.It is obvious that vehicles bring about changes in the aerodynamic shape of the main girder.Therefore,the influence of vehicles on vortex-excited resonance performance of vehicle-bridge systems,in terms of both amplitude and mode,should not be ignored.
