scholarly journals 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

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.

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

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.

scholarly journals Simulations of the Atmospheric Boundary Layer in a Wind Tunnel with Short Test Section

2013 ◽  
Vol 5 (3) ◽  
pp. 305-314 ◽  
Author(s):  
Luciana Bassi Marinho Pires ◽  
Igor Braga De Paula ◽  
Gilberto Fisch ◽  
Ralf Gielow ◽  
Roberto Da Mota Girardi
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Atmospheric Boundary Layer ◽  
Test Section ◽  
Short Test

A new low-turbulence wind tunnel for bird flight experiments at Lund University, Sweden

1997 ◽  
Vol 200 (10) ◽  
pp. 1441-1449 ◽  
Author(s):  
C J Pennycuick ◽  
T Alerstam ◽  
A Hedenström
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Test Section ◽  
Safety Net ◽  
Turbulence Level ◽  
Bird Flight ◽  
Contraction Ratio ◽  
Unrestricted Access ◽  
Side Walls ◽  
Air Speed

A new wind tunnel for experiments on bird flight was completed at Lund University, Sweden, in September 1994. It is a closed-circuit design, with a settling section containing five screens and a contraction ratio of 12.25. The test section is octagonal, 1.20 m wide by 1.08 m high. The first 1.2 m of its length is enclosed by acrylic walls, and the last 0.5 m is open, giving unrestricted access. Experiments can be carried out in both the open and closed parts, and comparison between them can potentially be used to measure the lift effect correction. The fan is driven by an a.c. motor with a variable-frequency power supply, allowing the wind speed to be varied continuously from 0 to 38 m s-1. The whole machine can be tilted to give up to 8 ° descent and 6 ° climb. A pitot-static survey in the test section showed that the air speed was within ±1.3 % of the mean at 116 out of 119 sample points, exceeding this deviation at only three points at the edges. A hot-wire anemometer survey showed that the turbulence level in the closed part of the test section was below 0.04 % of the wind speed throughout most of the closed part of the test section, rising to approximately 0.06 % in the middle of the open part. No residual rotation from the fan could be detected in the test section. No decrease in wind speed was detectable beyond 3 cm from the side walls of the closed part, and turbulence was minimal beyond 10 cm from the walls. The installation of a safety net at the entrance to the test section increased the turbulence level by a factor of at least 30, to 1.2 % longitudinally and 1.0 % transversely.

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