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

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.

Suppression of background noise in a transonic wind-tunnel test section

AIAA Journal ◽  
1975 ◽  
Vol 13 (11) ◽  
pp. 1467-1471 ◽  
Author(s):  
L. A. Schutzenhofer ◽  
P. W. Howard
Keyword(s):  
Wind Tunnel ◽  
Test Section ◽  
Background Noise ◽  
Wind Tunnel Test ◽  
Transonic Wind Tunnel

Control of separation in the concave portion of contraction to improve the flow quality

2009 ◽  
Vol 113 (1141) ◽  
pp. 177-182 ◽  
Author(s):  
K. Ghorbanian ◽  
M. R. Soltani ◽  
M. D. Manshadi ◽  
M. Mirzaei
Keyword(s):  
Wind Tunnel ◽  
Pressure Distribution ◽  
Turbulence Intensity ◽  
Test Section ◽  
Adverse Pressure Gradient ◽  
Wind Tunnel Experiments ◽  
Free Stream Turbulence ◽  
Static Pressure Distribution ◽  
Subsonic Wind Tunnel ◽  
Flow Quality

AbstractSubsonic wind tunnel experiments were conducted to study the effect of forced transition on the pressure distribution in the concave portion of contraction. Further more, the effect of early transition on the turbulence level in the test section of the wind tunnel is studied. Measurements were performed by installing several trip strips at two different positions in the concave portion of the contraction. The results show that installation of the trip strips, have significant effects on both turbulence intensity and on the pressure distribution. The reduction in the free stream turbulence as well as the wall static pressure distribution varied significantly with the location of the trip strip. The results confirm the significant impact of the tripped boundary layer on the control of adverse pressure gradient. The trip strip atX/L= 0.115 improves pressure distribution in contraction and reduces turbulence intensity in the test section, considerably.

scholarly journals Flow Angularity Investigations in an Automotive Slotted Wall Wind Tunnel

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4575
Author(s):  
Emil Ljungskog ◽  
Simone Sebben ◽  
Alexander Broniewicz
Keyword(s):  
Heat Exchanger ◽  
Wind Tunnel ◽  
Test Section ◽  
Vortical Flow ◽  
Settling Chamber ◽  
Force Measurements ◽  
Volvo Cars ◽  
Before And After ◽  
Ground System ◽  
Induced Flow

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.

scholarly journals ANALISA DISTRIBUSI KECEPATAN ALIRAN OPEN CIRCUIT TYPE SUBSONIC WIND TUNNEL MENGGUNAKAN PIPA PITOT DENGAN PEMBACAAN SENSOR TEKANAN MPXV7002DP

2019 ◽  
Vol 2 (2) ◽  
pp. 57
Author(s):  
Muhamad Hanifudin
Keyword(s):  
Wind Tunnel ◽  
Test Section ◽  
Open Circuit ◽  
Subsonic Wind Tunnel

Tuntutan memiliki wind tunnel semakin tinggi di mana wind tunnel bermanfaat untuk mahasiswa teknik yang akan mengadakan penelitian lanjutan yang berkenaan dengan gaya-gaya aerodinamis (drag, lift, side), fenomena aliran udara ataupun tentang pengembangan terowongan angin itu sendiri. Atas dasar tersebut kami bermaksud merancang dan membangun wind tunnel.Sebelum wind tunnel dapat dipakai untuk pengujian gaya-gaya terhadap benda, diperlukan pengujian distribusi kecepatan aliran udara pada wind tunnel. Pengujian distribusi kecepatan aliran wind tunnel biasanya dilakukan dengan menggunakan pipa pitot pembacaan manometer pipa U. Untuk mendapatkan hasil pengukuran yang lebih akurat dan cepat maka pembacaan tekanan diganti dengan sensor tekanan dikombinasikan dengan arduino. Sehingga data yang diperoleh nantinya akan bisa dikonversi otomatis menjadi kecepatan aliran dengan menggunakan program arduino. Setelah dilakukan penelitian pengukuran kecepatan aliran udara dengan menggunakan pipa pitot dan sensor tekanan MPXV7002DP dikombinasikan Arduino hasilnya lebih cepat dan lebih akurat karena dapat mengukur kecepatan yang lebih rendah dibanding manometer pipa U yaitu 2.55 m/s dibanding 4.031 m/s . Akan tetapi jangkauan maksimalya tidak setinggi manometer pipa U karena hanya ternyata hanya mampu membaca kecepatan lebih dari 2.55 m/s sampai 57.64 m/s. Sedangkan manometer pipa U dapat membaca kecepatan lebih dari 57.64 m/s. Hasil pengujian kecepatan aliran udara pada wind tunnel didapatkan bahwa kececepatan minimal aliran udara yang melewati test section adalah 11.81 m/s sedangkan kececepatan maksimal aliran udara yang melewati test section adalah 12.72 m/s. Distribusi kecepatan aliran udara Open Circuit Type Subsonic Wind Tunnel dapat dikatakan seragam tapi belum baik karena setelah diuji dengan Peta I-MR kecepatan aliran masih melewati batas kontrol.

scholarly journals An Experimental Study of Test Section Velocity Calibration for Low-Speed Wind Tunnel

2012 ◽  
Vol 40 (3) ◽  
pp. 230-236 ◽  
Author(s):  
Se-Yoon Oh ◽  
Jong-Geon Lee ◽  
Sung-Cheol Kim ◽  
Sang-Ho Kim ◽  
Seung-Ki Ahn
Keyword(s):  
Experimental Study ◽  
Wind Tunnel ◽  
Test Section ◽  
Low Speed ◽  
Velocity Calibration ◽  
Low Speed Wind Tunnel

scholarly journals A New Method for Adjusting Setting Angle of Rotor Blade for Axial Fan in Wind Tunnel

2019 ◽  
Vol 37 (3) ◽  
pp. 580-586
Author(s):  
Xiaoli Qu ◽  
Zebin Ren ◽  
Wenguo Yang ◽  
Yuanqiang Luo ◽  
Chenghua Cong
Keyword(s):  
Wind Tunnel ◽  
Flow Velocity ◽  
Test Section ◽  
Rotor Blade ◽  
New Method ◽  
Axial Fan ◽  
Low Speed ◽  
Rotating Speed ◽  
Setting Angle ◽  
Low Speed Wind Tunnel

Combining the fan aerodynamic efficiency with the wind tunnel pressure loss coefficient, a new equation which points out the inherent relationship of the fan blade setting angle, fan rotating speed and gas flow rate in wind tunnel circuit is derived according to the two-dimensional flow theory of the axial fan rotor blades and the aerodynamic characteristics of the low speed wind tunnel. So a new method for setting angle adjustment of fan rotor blade to satisfy the fan performance at off-design point by getting the test results of fan operation parameters but without the fan total pressure rise in the low speed wind tunnel is developed. Flowing the new method, the setting angle adjusting value of fan rotor blade was provided only with the fan rotating speed and flow velocity in the test section of a low speed wind tunnel directly before the fan setting angle altered, the adjusting target was achieved by the new blade setting angle successfully and the time and cost of the wind tunnel commissioning test were saved. The test results show that, after increasing the fan rotor blade setting angle by 4.5 degrees, when the flow velocity in the wind tunnel test section reaches 60 m/s, the fan rotating speed is 570 r/min, the deviation from the predicted fan rotating speed value of 575 r/min is 0.9%. For the same test section flow velocity, the predicted value of the fan rotating speed is in a good agreement with the real value, it proves that this method is reliable and accurate in practical application.

Effects of Turbulence on the Breakup of Round Liquid Jets in Gaseous Crossflow

2005 ◽  
Author(s):  
R. Sankarakrishnan ◽  
K. A. Sallam ◽  
F. W. Chambers
Keyword(s):  
Experimental Investigation ◽  
Wind Tunnel ◽  
Test Section ◽  
Drop Size ◽  
Liquid Surface ◽  
Liquid Jets ◽  
Liquid Jet ◽  
Surface Conditions ◽  
Subsonic Wind Tunnel ◽  
Primary Breakup

An experimental investigation of the effects of turbulence on primary breakup of round liquid jets subjected to gaseous crossflow is described. The paper investigates the effects of partial degrees of turbulence development in the liquid. Measurements of the properties of primary breakup were obtained using double-pulsed shadowgraphy in a subsonic wind tunnel having a test section of 0.3 m × 0.3 m × 0.6 m. Measurements included primary breakup regimes, conditions required for the onset of breakup, ligament properties along the liquid surface, drop size and velocity distributions after breakup along the liquid surface, conditions required for breakup of the liquid jet as a whole, and liquid jet trajectories.

scholarly journals Pengukuran Kualitas Kecepatan Angin pada Terowongan Angin di ILST BBTA3

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Novan Risnawan ◽  
F. Andree Yohanes ◽  
Sunarno Sunarno ◽  
Hetty Novianti ◽  
Yusron Feriadi
Keyword(s):  
Wind Tunnel ◽  
Test Section ◽  
Dynamic Pressure ◽  
Reference Value ◽  
Pitot Tube ◽  
Calibration Coefficient ◽  
Result Show ◽  
Flow Quality ◽  
Low Speed Wind Tunnel

AbstractCalibration check of Indonesia Low Speed Wind Tunnel (ILST) flow reference value have been performed at the beginning of 2018. Calibration check have been conducted to the calibration coefficient of predicted freestream static and dynamic pressure. This wind tunnel reference values is reffered to the static and dynamic pressure of a reference pitot tube that is installed at the center of turn table inside the test section. The test is conducted in empty test section. The calibration check result is very close to the previous values. This result show that flow quality of ILST wind tunnel is still maintained well for aerodynamic testing purposes.Keywords: Wind tunnel calibration, tunnel reference value. AbstrakPengecekan hasil kalibrasi besaran-besaran acuan aliran terowongan angin ILST telah selesai dilakukan pada awal tahun 2018. Pengecekan kalibrasi dilakukan terhadap koefisien kalibrasi tekanan statik dan tekanan dinamik terprediksi. Koefisien-koefisien referensi terowongan angin ini disesuaikan dengan tekanan statik dan tekanan dinamik yang dibaca oleh pitot tube acuan yang dipasang di tengah turn table di dalam seksi uji. Pengukuran dilakukan pada kondisi seksi uji kosong (empty test section). Hasil pengecekan kalibrasi acuan ini sangat dekat dengan hasil sebelumnya. Hasil kegiatan ini secara umum menunjukkan bahwa kualitas aliran terowongan angin ILST masih terpelihara dengan baik untuk keperluan pengujian aerodinamik.Kata Kunci : Kalibrasi terowongan angin, referensi terowongan angin. 

Sign in / Sign up

Export Citation Format

Share Document