Flow Angularity Investigations in an Automotive Slotted Wall Wind Tunnel

The Volvo Cars aerodynamic wind tunnel has had a vortical flow angularity pattern in the test section since its original commissioning in 1986. The vortical flow nature persisted after an upgrade in 2006, when the fan was replaced and a moving ground system was introduced. It has been hypothesized that the cause for this flow angularity pattern was leakages around the heat exchanger installed in the settling chamber. The present paper tests this hypothesis by measuring the flow angularity in the test section before and after sealing the leakages. The findings show that the leakage path around the heat exchanger does not influence the flow angularity, and that the current pattern is different compared to the commissioning after the upgrade. This prompted an investigation of the influence from the turbulence screens, which were changed after the upgrade commissioning. These investigations indicate that the probable cause of the vortical flow angularity pattern is residual swirl from the fan. Force measurements on a reference car with and without extra induced flow angularity show that the flow angles measured in the tunnel for regular operation are most likely small enough to not have a significant effect on the measured aerodynamic forces.

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ANALISIS DAN PERHITUNGAN PADA DAYA MOTOR UNTUK TEROWONGAN ANGIN (WIND TUNNEL) TIPE SUBSONIC DENGAN TEST SECTION 0,2 X 0,2 M UNTUK ALAT PERAGA MEKANIKA FLUIDA SKALA LABOLATORIUM

Mechonversio: Mechanical Engineering Journal ◽

10.51804/mmej.v2i2.615 ◽

2019 ◽

Vol 2 (2) ◽

pp. 25

Author(s):

Andi Tri G

Keyword(s):

Wind Tunnel ◽

Test Section ◽

Settling Chamber ◽

Energy Losses ◽

Air Volume

Aerodinamika yaitu salah satu bagian dari ilmu dinamika fluida yang mempelajari tentang gaya yang bekerja kepada suatu objek benda yang berada di dalam suatu aliran fluida. Pemecahan pada persoalan aerodinamika yang umumnya melibatkan penghitungan berbagai sifat pada aliran yang terjadi, semacam kecepatan, tekanan, temperatur, maupungaya masa jenis, sebagai suatu fungsi terhadap ruang dan waktu. Dengan mempelajari model - model aliran yang ada, maka akan memungkinkan untuk menghitung maupun memperkirakan momen dan gaya bekerja pada suatu objek yang berada pada aliran tersebut. Laporan secara eksperimen yang berguna dalam pemecahan permasalahan aerodinamika bisa didapat melalui berbagai macam metode, dan salah satu metode tersebut yaitu dengan menggunakan wind tunnel.Tujuan memperoleh angka air volume / CMH yang dibutuhkan pengujian pada (test section) di rangkaian terbuka wind tunnel. Mengetahui total keseluruhan kerugian pada tiap bagian rangkaian terbuka wind tunnel. Mengetahui dari hasil perhitungan daya motor pada fan yang benar dan sesuai.Dari perhitungan yang telah dilakukan maka nilai minimal air volume yang diperlukan pada bagian test section sebesar 2880,14 CMH (Cubic Meter Hour). Analisa dari perhitungan Energy losses (kerugian energi) dari setiap komponen dalam rangkaian terbuka wind tunnel yaitu settling chamber ( untuk nilai Honeycomb nilai K0 = 0,004687 dan screen nilai K1 = 0,004687) , contraction dengan nilai K2 = 0,02745, test section nilai K3 = 0,0675 , Diffuser nilai K4 = 0,72962, dan saluran discharge nilai K5 = 0,1667887. Maka total dari keseluruhan nilai tersebut dijumlahkan Ktotal = 0,20014656. Perhitungan nilai daya motor yang dibutuhkan pada hasil perhitungan pada BAB 4 sebesar 233,51 W -> ½ HP.

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A Study of the Pulsations of Flow in the Settling Chamber and Their Relationship with the Pulsations of the Supersonic Flow

Siberian Journal of Physics ◽

10.25205/2541-9447-2019-14-2-77-85 ◽

2019 ◽

Vol 14 (2) ◽

pp. 77-85

Author(s):

L. V. Afanasev ◽

A. A. Yatskih ◽

A. D. Kosinov ◽

Yu. G. Yermolaev ◽

N. V. Semionov ◽

...

Keyword(s):

Experimental Study ◽

Supersonic Flow ◽

Wind Tunnel ◽

Test Section ◽

Free Stream ◽

Settling Chamber ◽

Flow Pulsation ◽

Supersonic Wind Tunnel ◽

Flow Pulsations

Experimental study of the influence of flow pulsation in settling chamber on the supersonic free stream disturbances was carried out. Data on the pulsations in the settling chamber and the efficiency of deturbulization system as well as the correlation of pulsations of the flow of settling chamber and flow pulsations in test section of T-325 supersonic wind tunnel of ITAM SB RAS were obtained.

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Improvements of a Hard-Wall Closed Test-Section of a Subsonic Wind Tunnel for Aeroacoustic Testing

10.20855/ijav.2021.26.31803 ◽

2021 ◽

Vol 26 (3) ◽

pp. 248-258

Author(s):

Odenir de Almeida ◽

Fernando M. Catalano ◽

Lourenco Tercio Pereira

Keyword(s):

Wind Tunnel ◽

Test Section ◽

Background Noise ◽

Noise Sources ◽

Subsonic Wind Tunnel ◽

Array Measurements ◽

Before And After ◽

Noise Measurements ◽

Low Speed Wind Tunnel ◽

Lower Background

For achieving accurate aeroacoustic measurements to the aircraft industry, a low-speed wind tunnel, primarily designed for aerodynamic testing, is modified to provide lower background noise environment. Based on data from single microphone at different wind tunnel locations and microphone phased-array measurements inside the test-section, the main noise sources are identified and feasible alternatives are implemented for reducing the background noise such as new acoustically treated corner-vanes and sidewall lining located upstream the drive system. The acoustically transparent concept for the test-section is also investigated showing promising results for further improvements in the wind tunnel. Results are presented for sound pressure levels from single microphone measurements at different locations in the wind tunnel as well as from the beamforming array inside the test-section. Background noise measurements before and after improvements confirm that the ability of performing aeroacoustic tests has significantly increased with noise reduction of 5 dB inside the test-section.

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A blockage correction for automotive testing in a wind tunnel with closed test section

Journal of Wind Engineering and Industrial Aerodynamics ◽

10.1016/0167-6105(86)90080-2 ◽

1986 ◽

Vol 22 (2-3) ◽

pp. 149-167 ◽

Cited By ~ 30

Author(s):

E. Mercker

Keyword(s):

Wind Tunnel ◽

Test Section ◽

Blockage Correction

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Scaling of Heat Exchanger Tubes by Calcium Carbonate

Journal of Heat Transfer ◽

10.1115/1.3450419 ◽

1975 ◽

Vol 97 (4) ◽

pp. 504-508 ◽

Cited By ~ 39

Author(s):

A. P. Watkinson ◽

O. Martinez

Keyword(s):

Heat Exchanger ◽

Calcium Carbonate ◽

Mathematical Models ◽

Flow Velocity ◽

Test Section ◽

Suspended Solids ◽

Bulk Temperature ◽

Fouling Resistance ◽

Steam Temperature ◽

Scaling Process

Scaling of copper heat exchanger tubes has been studied under conditions that promote rapid and severe scaling. Artificially hardened water of high dissolved and suspended solids is recirculated through a heated test section operated at constant steam temperature. The effects of flow velocity, tube diameter, and bulk temperature on the asymptotic fouling resistance have been determined. Results are interpreted in terms of mathematical models of the scaling process.

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Comparison of ornithopter wind tunnel force measurements with free flight

2014 IEEE International Conference on Robotics and Automation (ICRA) ◽

10.1109/icra.2014.6907097 ◽

2014 ◽

Cited By ~ 10

Author(s):

Cameron Rose ◽

Ronald S. Fearing

Keyword(s):

Wind Tunnel ◽

Force Measurements ◽

Free Flight

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Hypersonic Free Flight Investigation on Rudder Reflection of Aircraft

Proceedings ◽

10.3390/icem18-05434 ◽

2018 ◽

Vol 2 (8) ◽

pp. 542

Author(s):

Fei Xue ◽

Yuchao Wang ◽

Zenghui Jiang ◽

Yinong Yang

Keyword(s):

Wind Tunnel ◽

Degrees Of Freedom ◽

Wind Tunnel Test ◽

Model Matching ◽

Free Flight ◽

Control Effect ◽

Time Curve ◽

Hypersonic Wind Tunnel ◽

Before And After ◽

Ejection Mechanism

In order to study the control effect of the rudder surface of the hypersonic vehicle and the coupling dynamic characteristics of the rudder surface deflection and the flight attitude, a technical platform for the deflection and motion coupling of the aircraft rudder surface was designed. The platform ejection mechanism can launch the model into the wind tunnel flow field according to the preset attitude, and model can free flight without support interference. The innovative design of the model internal rudder partial system can guarantee the model to deflect the rudder surface in the free flight process, simulate the real steering process of the aircraft. By changing spring with different springs, the speed of the rudder surface can be changed. The dual optical path and image acquisition technology can capture the motion picture before and after the deflection of the rudder surface from two angles. After the image is matched by model matching, the six degrees of freedom parameter of the model can be changed with the time curve before and after the deflection of the rudder surface, and the area of the six freedom degree curve of the different state model is compared. In other words, the specific influence of dynamic rudder rotation on the motion of the model is known. The wind tunnel test of the model in the hypersonic wind tunnel of the 500 mm is carried out using this platform. The test results are highly repeatable, and the test platform technology is mature and reliable.

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