Studi Eksperimental Desain Kontraksi Wind Tunnel Bentuk Nosel Chamber Positif & Negatif

Sigit Budi Hartono(1*)


(1) Teknik Mesin, Fakultas Vokasi Institut Teknologi Nasional Yogyakarta
(*) Corresponding Author

Abstract


Penelitian ini membandingkan desain kontraksi wind tunnel dengan bentuk nosel chamber positif dan negative dengan beberapa parameter yang diteliti yaitu pengaruh geometri kontraksi Wind Tunnel yang berbentuk nosel chamber positif dan negatif, karakteristik medan aliran (velocity dan pressure) dari aliran, berapa nilai intensitas turbulen aliran udara. Desain Wind Tunnel pada tahap awal akan dilakukan modeling dengan simulasi komputer, yang berguna sebagai permodelan desain bentuk dan geometri yang paling baik dan optimal, dengan tinjauan berbagai aspek dan parameter aerodinamika sesuai dengan kebutuhan penelitian, sehingga bagian-bagian utama terowongan angin seperti, honey comb, kontraksi, seksi uji, diffuser dan fan isap, akan dirancang memenuhi aspek aerodinamis. Studi eksperimental dilakukan untuk melihat dan mengidentifikasi fenomena aspek aerodinamis, dengan menggunakan model nosel bentuk chamber positif dan negatif yang berukuran skalatis dan dilakukan di dalam Wind Tunnel. Ujicoba dilakukan dengan metode eksperimen pada wind tunnel  pada tiga tingkat variasi kecepatan, yaitu; kecepatan rendah 4 m/s, kecepatan sedang 8 m/s dan kecepatan tinggi 12 m/s, menggunakan visualisai gambar dan dikombinasikan dengan pengukuran data variasi kecepatan aliran udara, agar dapat menghasilkan aliran kecepatan angin pada kisaran minimum dan maksimum di bagian seksi uji Wind Tunnel (rata-rata 0,5 ~ 8 m/s). pada nilai intensitas turbulensi yang paling rendah. Hasil penelitian ini menunjukkan bahwa secara umum bentuk kontraksi nosel camber (-) memiliki performasi yang lebih baik pada kecepatan 6 m/s ke atas, karena luas area up-stream dan down stream yang sama sehingga selisih kecepatan yang dihasilkan dari kedua model uji menjadi sama, walaupun dengan nilai kecepatan hasil yang berebeda pada kecepatan input yang sama, di daerah up stream dan down stream terjadi ketidak seragaman kecepatan aliran, sehingga hasil ini menunjukan bahwa karakter aliran yang dihasilkan pada nosel (+) membentuk aliran yang tidak seragam kecepatannya dan Nosel (-) variasi kecepatan alirannya lebih seragam, ini menunjukkan bahwa karakter aliran yang dihasilkan pada nosel (-) lebih baik bila dibandingkan nosel (+).

-------

This study compares the design of wind tunnel contractions with positive and negative chamber nozzles with several parameters studied, namely the effect of wind tunnel contraction geometry in the form of positive and negative chamber nozzles, flow field characteristics (velocity and pressure) of the flow, what is the value of the turbulent intensity of air flow. In the early stages of the Wind Tunnel design, modeling with computer simulation will be carried out, which is useful as the best and optimal modeling of the shape and geometry design, with a review of various aspects and aerodynamic parameters according to research needs, so that the main parts of the wind tunnel such as honey comb, contraction, test section, diffuser, and suction fan, will be designed according to aerodynamic aspects, using a nozzle model of positive and negative chamber shapes with scalar size and carried out in the Wind Tunnel. The experiment was conducted using an experimental method in a wind tunnel at three levels of speed variation, namely; low speed 4 m/s, medium speed 8 m/s, and high speed 12 m/s, using image visualization and combined with measurement of airflow velocity variation data, to produce wind speed flow in the minimum and maximum range in the Wind test section. Tunnel (average 0.5 ~ 8 m/s) at the lowest turbulence intensity value. The results of this study indicate that in general, the contraction form of the chamber nozzle (-) has better performance at speeds of 6 m/s and above because the upstream and down-stream areas are the same so that the difference in velocity resulting from the two test models is the same, although with different results velocity values at the same input speed, in the upstream and downstream areas there is a non-uniform flow velocity, so this result shows that the flow character generated at the nozzle (+) forms a flow that is not uniform in speed and the nozzle (-) the variation of flow velocity is more uniform, this indicates that the flow characteristics produced at the (-) nozzle are better than the (+) nozzle.


Keywords


Wind Tunnel; Aerodinamics; Nossel; Contraction

Full Text:

PDF

References


Andrew Welsh,. 2013. Low Turbulence Wind Tunnel Design and Wind Turbine Wake Characterization. University of Wisconsin Milwaukee, Theses and Dissertations. UWM Digital Commons.

Bjorn Lindgren & Arne V. Johansson,. 2002. Design and Evaluation of a Low-Speed. Wind-Tunnel with Expanding Corners. Department of Mechanics, Technical Reports from Royal Institute of Technology Department of Mechanics SE-100 44 Stockholm, Sweden.

Harold Sherwood Boudreau III,. 2009. Design, Construction, and Testing of an Open Atmospheric Boundary Layer Wind Tunnel. Theses and Dissertations, University of florida,

Ismail, Samsul K, Purnomo, Sarjiya, Sulaiman Tampubolon, Azhim A and Inderanata,. 2015. Modification of Open Circuit Wind Tunnel. ARPN Journal of Engineering and Applied Sciences, Asian Research Publishing Network (ARPN). VOL. 10, NO. 18, OCTOBER 2015. ISSN 1819-6608.

Nelton Koo Chwee Yang,. 2012. Design of Wind Tunnel (Fluid Flow Analysis), Theses and Dissertations. Faculty of Manufacturing Engineering ,Universiti Malaysia Pahang.

Mauro S, Brusca S.b, Lanzafame R, Famoso F, Galvagno A. and Messina M,. 2017. Small-Scale Open-Circuit Wind Tunnel: Design Criteria, Construction and Calibration. International Journal of Applied Engineering Research ISSN 0973-4562 Volume 12, Number 23 (2017) pp. 13649-13662.

Mayya, R., 2012, The wind tunnel performance investigation by using the modeling and simulation. Energy Procedia, Vol 19, pp. 80 – 86

M. A. G. Hernández, A. I. M. López, A. A. Jarzabek, J. M. P. Perales, and Y. Wu, 2013 “Design Methodology for a Quick and Low-Cost Wind Tunnel,” in Wind Tunnel Designs andTheir Diverse Engineering Application, InTech, pp. 3–28

P. Moonen, B. Blocken, and J. Carmeliet, 2007 “Indicators for the evaluation of wind tunnel test section flow quality and application to a numerical closed-circuit wind tunnel,” J. Wind Eng. Ind. Aerodyn., vol. 95, no. 9–11, pp. 1289–1314.

Serhat Senol, Ali Cinar,. 2009. Design and Flow Simulation of an Open Circuit Wind Tunnel. Kocaeli University Turkiye. EnginSoft International Conference.

Yi-Huan Kao, Zhou Wei Jiang and Sheng Cyuan Fang,. 2017. A Computational Simulation Study of Fluid Mechanics of Low-SpeedWind Tunnel Contractions. Mdpi journal.


Article Metrics

Abstract view : 72 times
PDF - 15 times

DOI: https://doi.org/10.26714/traksi.21.2.2021.%25p

Refbacks

  • There are currently no refbacks.


Copyright (c) 2021 TRAKSI

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.


TRAKSI : Majalah Ilmiah Teknik Mesin

ISSN : 1693-3451 (Pinted) e-ISSN : 2579-9738 (Online)

Published by: LP2M Unimus bekerjasama dengan APTI (Asosiasi Profesi Teknik Indonesia)  

 
ADDRESS

Jl. Kasipah No. 12 Semarang

E-mail: traksi@unimus.ac.id Call: 0248445768


Sponsors

Asosiasi Profesi Teknik Indonesia (APTI)

Website: www.apti.or.id