Comparison Research on Aerodynamic Drags and Pressure Coefficients of Reference Car Models in Automotive Wind Tunnel

2014 ◽  
Vol 989-994 ◽  
pp. 2834-2838 ◽  
Author(s):  
Ying Chao Zhang ◽  
Wei Ding ◽  
Zhe Zhang ◽  
Jie Li
Keyword(s):  
Wind Tunnel ◽  
Test Data ◽  
Wind Tunnels ◽  
Actual Situation ◽  
Wind Tunnel Tests ◽  
Reliable Test ◽  
Pressure Coefficients ◽  
Reference Models ◽  
Comparison Research ◽  
Research Show

The aerodynamic drags of different reference car models were investigated to calibrate the performance of the Automotive Wind Tunnel in Jilin University. The two kinds of reference models--MIRA and SAE reference car models were involved in this paper, considering the actual situation of the Automotive Wind Tunnel in Jilin University. The results of the research show that the Automotive Wind Tunnel in Jilin University can meet the demand for automotive wind tunnel tests and it can get the same performances as other wind tunnels have and reliable test data can be obtained in it.

Validation of the AeroDyn Subroutines Using NREL Unsteady Aerodynamics Experiment Data

2002 ◽  
Author(s):  
David J. Laino ◽  
A. Craig Hansen ◽  
Jeff E. Minnema
Keyword(s):  
Wind Tunnel ◽  
Test Data ◽  
Complex Dynamics ◽  
Angle Of Attack ◽  
Unsteady Aerodynamics ◽  
Hysteresis Loops ◽  
Structural Vibration ◽  
Detailed Knowledge ◽  
Vibration Modes ◽  
Wind Tunnel Tests

Completion of the full-scale wind tunnel tests of the NREL Unsteady Aerodynamics Experiment (UAE) Phase VI allowed validation of the AeroDyn wind tuxbine aerodynamics software to commence. Detailed knowledge of the inflow to the UAE was the bane of prior attempts to accomplish any in-depth validation in the past. The wind tunnel tests permitted unprecedented control and measurement of inflow to the UAE rotor. The data collected from these UAE tests are currently under investigation as part of an effort to better understand wind turbine rotor aerodynamics in order to improve aero-elastic modeling techniques. Preliminary results from this study using the AeroDyn subroutines are presented, pointing to several avenues toward improvement. Test data indicate that rotational effects cause more static stall delay over a larger portion of the blades than predicted by current methods. Despite the relatively stiff properties of the UAE, vibration modes appear to influence the aerodynamic forces and system loads. AeroDyn adequately predicts dynamic stall hysteresis loops when appropriate steady, 2-D airfoil tables are used. Problems encountered include uncertainties in converting measured inflow angle to angle of attack for the UAE phase VI. Future work is proposed to address this angle of attack problem and to analyze a slightly more complex dynamics model that incorporates some of the structural vibration modes evident in the test data.

scholarly journals Sensitivity Investigation on the Pressure Coefficients Non-Dimensionalization

2021 ◽  
Vol 6 (4) ◽  
pp. 53
Author(s):  
Fabio Rizzo
Keyword(s):  
Wind Tunnel ◽  
Wind Velocity ◽  
Time History ◽  
Wind Tunnels ◽  
Pressure Coefficients ◽  
Box Section ◽  
Large Structures ◽  
Suspended Bridge

The scaling of large structures to investigate their aerodynamics in wind tunnels is a common and robust procedure to estimate important magnitudes, including pressure coefficients. Different aspects can affect the estimation of pressure coefficients; four examples are the non-dimensionalization, blockage, non-stationarity, and non-Gaussianity of the wind tunnel velocity. This paper shows the variability of pressure coefficients due to these four aspects for the case study of a closed box section of a suspended bridge. It was estimated that the pressure coefficients of similar pressure taps vary significantly due to different sets of wind velocity time history used to non-dimensionalize the wind tunnel pressures. In addition, the stationarity of the wind velocity process was not confirmed for all wind velocity sets and the non-Gaussianity of the wind velocity time history was confirmed.

Manufacture and Material Considerations in Wind Tunnel Experimentation

2014 ◽  
Vol 607 ◽  
pp. 694-699
Author(s):  
H. Yu ◽  
Noor A. Ahmed ◽  
T.G. Flynn
Keyword(s):  
Wind Tunnel ◽  
Test Data ◽  
Cost Effective ◽  
Wind Tunnels ◽  
Successful Outcome ◽  
Wind Tunnel Experiments ◽  
Test Program ◽  
Test Models ◽  
Essential Components ◽  
Selection Of

Appropriate selection of methods of manufacture and materials of test models are essential components physical experimentations using wind tunnels. The present paper is written with a view to highlight some of the aspects that need careful considerations in formulating cost-effective test program and gathering of accurate test data for successful outcome of such wind tunnel experiments.

scholarly journals Multidimensional Vibration Suppression Method with Piezoelectric Control for Wind Tunnel Models

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3998 ◽  
Author(s):  
Mengde Zhou ◽  
Wei Liu ◽  
Linlin Tang ◽  
Zhuang Yao ◽  
Zhengquan Wen ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Test Data ◽  
Evaluation Method ◽  
Vibration Suppression ◽  
Damping Ratio ◽  
Piezoelectric Actuators ◽  
Velocity Feedback ◽  
Wind Tunnel Tests ◽  
Assumed Mode Method ◽  
Suppression Method

In wind tunnel tests, the low-frequency and large-amplitude vibration of the cantilever sting result in poor test data in pitch plane and yaw plane, more seriously, even threatens the safety of wind tunnel tests. To ensure the test data quality, a multidimensional vibration suppression method is proposed to withstand the vibration from any direction, which is based on a system with stackable piezoelectric actuators and velocity feedback employing accelerometers. Firstly, the motion equation of the cantilever sting system is obtained by Hamilton’s principle with the assumed mode method. Then, the multidimensional active control mechanism is qualitatively analyzed and a negative velocity feedback control algorithm combined with a root mean square (RMS) evaluation method is introduced to realize active mass and active damping effect, meanwhile, a weight modification method is performed to determine the sequence number of the stacked piezoelectric actuators and the weight of control voltages in real time. Finally, a multidimensional vibration suppression system was established and verification experiments were carried out in lab and a transonic wind tunnel. The results of lab experiments indicate that the damping ratio of the system is improved more than 4.3 times and the spectrum analyses show reductions of more than 23 dB. In addition, wind tunnel test results have shown that for the working conditions (α = −4~10° with γ = 0° or α = −4~10° with γ = 45°) respectively at 0.6 Ma and 0.7 Ma, the remainder vibration is less than 1.53 g, which proves that the multidimensional vibration suppression method has the ability to resist vibration from any direction to ensure the smooth process of wind tunnel tests.

Comparison of Wind Pressure Coefficients with Wind Load Provisions

2013 ◽  
Vol 831 ◽  
pp. 124-128
Author(s):  
Jong Won Lee ◽  
Yun Bae Kong ◽  
Sung Woo Shin
Keyword(s):  
Wind Tunnel ◽  
Test Data ◽  
Wind Tunnel Test ◽  
Wind Load ◽  
External Pressure ◽  
Wind Pressure ◽  
Experiment Data ◽  
Pressure Coefficients ◽  
Aerodynamic Database ◽  
The University

This study has compared the equivalent external pressure coefficients, (GCpf)eq, with 6 wind load provisions and wind tunnel test data. The wind load provisions are the ASCE 7-10, NBCC 2010, AS/NZS 2011, EN 2005, AIJ 2004 and KBC 2009. Experiment data on low-rise building have been obtained at the University of Western Ontario (UWO) to contribute to the NIST aerodynamic database [. For the experiment, a model with 1:12 of roof slope and 4.9 and 12.2m of eave height was used under open terrain conditions (See also Ref. [). (GCpf)eq was re-normalized based on the external pressure coefficients, GCpf, of ASCE 7-10. When compared to (GCpf)eq of the experiment data with 4.9m of eave height, consequently, ASCE 7-10 (81%), NBCC 2010 (84%), AS/NZS 2011 (70%), AIJ 2004 (68%) and KBC 2009 (53%) were all underestimated. Among them, KBC 2009 reveals the lowest value. On the contrary, EN2005 was overestimated with 122%. When the eave height was 12.2m, in addition, the same pattern was observed in most codes. EN2005 was slightly overestimated with 115%.

Introduction to Automatic Shutdown System for Flutter Test of High Speed Wind Tunnel

2014 ◽  
Vol 1030-1032 ◽  
pp. 1584-1587
Author(s):  
Li Yu ◽  
Bin Bin Lv ◽  
Yu Yan ◽  
Hong Tao Guo ◽  
Jun Zha ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Wind Tunnels ◽  
Subcritical State ◽  
Delayed Response ◽  
Wind Tunnel Tests ◽  
Manual Measurement ◽  
Unsafe Condition

This paper introduces an automatic shutdown system for model protection during the flutter test in high speed wind tunnels. This automatic shutdown system can be used to determine any unsafe condition through model flutter signals before triggering shutdown of wind tunnels, solving problems of delayed response and mistakes happen during manual measurement of subcritical state of model flutter. The reliability and effectiveness of this system have been proved good via wind tunnel tests, hence the possibility of damage to the model caused by flutter during the flutter test of high speed wind tunnels can be decreased.

scholarly journals CFD-Based Wind Field Correction Method for Terrain Wind Tunnel Tests

2021 ◽  
Vol 2083 (3) ◽  
pp. 032083
Author(s):  
Qi Zhou ◽  
Yuxiang Zhu ◽  
Yu Wang ◽  
Jiceng Han
Keyword(s):  
Wind Tunnel ◽  
Test Data ◽  
Wind Field ◽  
Cfd Simulation ◽  
Wind Tunnel Test ◽  
Correction Method ◽  
Measuring Instruments ◽  
Mountainous Area ◽  
Test Results ◽  
Wind Tunnel Tests

Abstract At present, the wind tunnel test results will have certain deviation and distortion when the wind tunnel test is conducted on certain mountainous terrain with complex local terrain and large variation of wind field characteristics due to the accuracy range of the measuring instruments used in wind tunnel test. In order to correct and obtain correct wind tunnel test results, the wind tunnel tests and numerical simulations were conducted on a super-large bridge in the mountainous area of Southwest China, and the wind parameters of the wind field at the bridge site were obtained. The CFD results were compared with the wind tunnel test results to confirm the credibility of the CFD results; a method was proposed to correct the deviated wind tunnel test data based on the CFD simulation results; the deviated wind tunnel test data were corrected and predicted with the above method, and a more satisfactory correction result was obtained.

Effects of Geometrical Factors on Wind Pressure Characteristics of Cylindrical Roofs with Wind Tunnel Tests

2013 ◽  
Vol 351-352 ◽  
pp. 284-289 ◽  
Author(s):  
Bo Chen ◽  
Qing Shan Yang
Keyword(s):  
Wind Tunnel ◽  
Probability Distributions ◽  
Wind Pressure ◽  
Wind Tunnel Tests ◽  
Pressure Coefficients ◽  
High Rise ◽  
Mean Pressure ◽  
The Mean ◽  
Geometrical Factors ◽  
Pressure Characteristics

With wind tunnel tests, simultaneous pressure measurements are made on 4 cylindrical roof models with different rise-span ratios and roof inclinations. Effects of these geometrical factors on wind pressure characteristics of the roofs are investigated, including mean pressure coefficients, RMS pressure coefficients, skewness, kurtosis, and probability distributions of wind pressure. Results show that the mean vertical wind force coefficient of high rise-span ratio roof is larger than that of the low rise-span ration roof; the mean pressure coefficient distribution of the low rise-span ratio roof is similar to that of RMS pressure coefficients and the skewness (or the kurtosis); the vortex center line occurs at the windward edge for the low rise-span ratio roof with inclination 0°, which occurs at the roof apex for the high rise-span ratio roof. The roof inclination has more effects on the low rise-span ratio roof, the vortex moves from the windward edge to the apex for the roof with inclination 7.2°when the wind flows from the low eave to the high eave. The distribution of the skewness is strongly correlative to that of the kurtosis. The probability distributions of the roof edges and corners deviate obviously from the Guass distribution. If this point is ignored, the peak suction pressure will be underestimated.

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