In Depth Cd/Fuel Economy Study Comparing SAE Type II Results with Scale Model Rolling Road and Non-rolling Road Wind Tunnel Results

Author(s):  
Adrian Reynard ◽  
Mike Camosy ◽  
Fritz Marinko ◽  
Henri Kowalczyk ◽  
Tim Jennings
Keyword(s):  
2021 ◽  
Vol 11 (8) ◽  
pp. 3315
Author(s):  
Fabio Rizzo

Experimental wind tunnel test results are affected by acquisition times because extreme pressure peak statistics depend on the length of acquisition records. This is also true for dynamic tests on aeroelastic models where the structural response of the scale model is affected by aerodynamic damping and by random vortex shedding. This paper investigates the acquisition time dependence of linear transformation through singular value decomposition (SVD) and its correlation with floor accelerometric signals acquired during wind tunnel aeroelastic testing of a scale model high-rise building. Particular attention was given to the variability of eigenvectors, singular values and the correlation coefficient for two wind angles and thirteen different wind velocities. The cumulative distribution function of empirical magnitudes was fitted with numerical cumulative density function (CDF). Kolmogorov–Smirnov test results are also discussed.


Author(s):  
Kun Chen ◽  
Zhiwei Shi ◽  
Shengxiang Tong ◽  
Yizhang Dong ◽  
Jie Chen

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.


2013 ◽  
Vol 115 (2) ◽  
pp. 211-219 ◽  
Author(s):  
Merlijn De Paepe ◽  
Jan G. Pieters ◽  
Wim M. Cornelis ◽  
Donald Gabriels ◽  
Bart Merci ◽  
...  

1999 ◽  
Author(s):  
W. Beaulieu ◽  
V. Bityurin ◽  
A. Klimov ◽  
S. Leonov ◽  
A. Pashina ◽  
...  

1985 ◽  
Vol 1 (2) ◽  
pp. 105-110 ◽  
Author(s):  
A. J. Dutt

This paper deals with the investigation of wind loading on the pyramidal roof structure of the Church of St Michael in Newton, Wirral, Cheshire, England, by wind tunnel tests on a 1/48 scale model. The roof of the model was flat in the peripheral region of the building while in the inner region there was a grouping of four pyramidal roofs. Wind tunnel experiments were carried out; wind pressure distribution and contours of wind pressure on all surfaces of the pyramid roofs were determined for four principal wind directions. The average suctions on the roof were evaluated. The highest point suction encountered was — 4q whilst the maximum average suction on the roof was —0·86q. The results obtained from wind tunnel tests were used for the design of pyramidal roof structures and roof coverings for which localised high suctions were very significant.


2020 ◽  
Vol 12 (2) ◽  
pp. 168781401984047
Author(s):  
Wonyoung Jeon ◽  
Jeanho Park ◽  
Seungro Lee ◽  
Youngguan Jung ◽  
Yeesock Kim ◽  
...  

An experimental and analytical method to evaluate the performance of a loop-type wind turbine generator is presented. The loop-type wind turbine is a horizontal axis wind turbine with a different shaped blade. A computational fluid dynamics analysis and experimental studies were conducted in this study to validate the performance of the computational fluid dynamics method, when compared with the experimental results obtained for a 1/15 scale model of a 3 kW wind turbine. Furthermore, the performance of a full sized wind turbine is predicted. The computational fluid dynamics analysis revealed a sufficiently large magnitude of external flow field, indicating that no factor influences the flow other than the turbine. However, the experimental results indicated that the wall surface of the wind tunnel significantly affects the flow, due to the limited cross-sectional size of the wind tunnel used in the tunnel test. The turbine power is overestimated when the blockage ratio is high; thus, the results must be corrected by defining the appropriate blockage factor (the factor that corrects the blockage ratio). The turbine performance was corrected using the Bahaj method. The simulation results showed good agreement with the experimental results. The performance of an actual 3 kW wind turbine was also predicted by computational fluid dynamics.


Vehicles ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 318-341
Author(s):  
Chen Fu ◽  
Mesbah Uddin ◽  
Chunhui Zhang

With the fast-paced growth of computational horsepower and its affordability, computational fluid dynamics (CFD) has been rapidly evolving as a popular and effective tool for aerodynamic design and analysis in the automotive industry. In the real world, a road vehicle is subject to varying wind and operating conditions that affect its aerodynamic characteristics, and are difficult to reproduce in a traditional wind tunnel. CFD has the potential of becoming a cost-effective way of achieving this, through the application of different boundary conditions. Additionally, one can view wind tunnel testing, be it a fixed-floor or rolling road tunnel, as a physical simulation of actual on-road driving. The use of on-road track testing, and static-floor, and rolling-road wind tunnel measurements are common practices in industry. Subsequently, we investigated the influences of these test conditions and the related boundary conditions on the predictions of the aerodynamic characteristics of the flow field around a vehicle using CFD. A detailed full-scale model of Hyundai Veloster with two vehicle configurations, one with the original and the other with an improved spoiler, were tested using a commercial CFD code STAR-CCM+ from Siemens. Both vehicle configurations were simulated using four different test conditions, providing overall eight different sets of simulation settings. The CFD methodology was validated with experimental data from the Hyundai Aero-acoustic Wind Tunnel (HAWT), by accurately reproducing the test section with static floor boundary conditions. In order to investigate the effect of the blockage ratio on the aerodynamic predictions, the vehicle models were then tested with moving ground plus rotating wheel boundary conditions, using a total of four virtual wind tunnel configurations, with tunnel solid blockage ratios ranging from 1.25%, which corresponds to the actual HAWT, to 0.04%, which presents an open air driving condition.


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