STUDI NUMERIK PENGARUH VARIASI KEMIRINGAN DAN KETINGGIAN STEP TERHADAP MEDAN ALIRAN MELALUBACKWARD-FACING STEP

Heydar Nur Fahmi  -  Departement of Mechanical Engineering, Diponegoro University, Indonesia
Khoiri Rozi  -  Departement of Mechanical Engineering, Diponegoro University, Indonesia
*Berkah Fajar Tamtomo Kiono scopus  -  Departement of Mechanical Engineering, Diponegoro University, Indonesia

Citation Format:
Abstract

Penelitian ini mengkaji performa aliran saat melewati saluran tertutup berbentuk backward-facing step (BFS). Metode penelitian yang digunakan adalah Computational Fluid Dynamics (CFD) berbasis ANSYS FLUENT 2022 dengan model turbulensi k-ε realizable. Pengaruh kemiringan dan perubahan tinggi step terhadap karakteristik distribusi aliran disimulasikan dengan dua variasi bilangan Reynolds yaitu Re = 1,5 x 104 dan 9 x 104. Hasil simulasi dari penelitian ini mengungkapkan bahwa perubahan kemiringan dan ketinggian step menyebabkan perubahan pada zona resirkulasi. Dimana efek perubahan kemiringan step memperlihatkan bahwa semakin besar sudut kemiringan step menyebabkan semakin berkurangnya zona resirkulasi dan panjang reattachment yang terbentuk. Sebaliknya, semakin bertambah tinggi step menyebabkan semakin besar zona resirkulasi dan panjang jarak reattachment yang terbentuk. Pengaruh perubahan energi kinetik turbulen dan distribusi tekanan akibat perubahan kemiringan dan ketinggian step juga ditemukan dalam penelitian ini. Setiap pertambahan sudut kemiringan step menyebabkan energi kinetik turbulen dan distribusi tekanan semakin kecil. Sedangkan setiap kenaikan ketinggian step menyebabkan energi kinetik turbulen dan distribusi tekanan semakin besar. Efek perbedaan antara dua bilangan Reynolds yang diuji pada semua variasi kemiringan dan ketinggian step juga menghasilkan perubahan terhadap pola pembentukan resirkulasi dan panjang reattachment dari backward-facing step yang diuji.

 

This study aims to examine the flow performance when passing through a backward-facing step (BFS) channel. The method used in this research is Computational Fluid Dynamics (CFD) based on ANSYS FLUENT 16 with a realizable k-ε turbulence model. The effect of changing the height and slope of the steps on the flow characteristics is simulated with two different Reynolds numbers, namely Re = 1.5 x 104 and 9 x 104. The simulation results from this study reveal that changes in step height cause changes in the recirculation zone and reattachment distance, where The higher the step, the larger the recirculation zone and the longer the reattachment distance is formed. The effect of changing the slope angle of the steps in this study shows that the greater the slope of the steps, the less the recirculation zone and the reattachment length are formed. In this study it was also found that at each step height increase the turbulent kinetic energy increases. Meanwhile, the increase in the angle of inclination of the step causes the turbulent kinetic energy to decrease. The effect of changing the difference between the two Reynolds numbers tested did not produce significant changes to the pattern of recirculation formation and reattachment length with respect to all variations of step height and step slope from the backward-facing step that was tested.

Fulltext View|Download
Keywords: Backward Facing Step, Computational Fluid Dynamics, k-ε realizable
Article Info
Section: Articles
Language : ID
Recent articles
SIMULASI NUMERIK CYCLONE SEPARATOR PADA PENGGILINGAN PADI PENGARUH TEMPERATUR SINTERING TERHADAP KARAKTERISASI POROUS HIDROAKSIAPATIT CANGKANG KERANG HIJAU YANG DIBUAT MENGGUNAKAN METODE POLYURETHANE SPONGE REPLICATION PENGUJIAN TARIK SECARA TERPUTUS PADA BAJA KARBON RENDAH AISI 1018 More recent articles
  1. Armaly B. F., Durst F., Pereira J. C. F., & Schonung B. (1983). Experimental and Theoretical Investigation of Backward-Facing Step Flow. Journal of Fluid Mechanics 127, 473-496
  2. Chen Lin, dkk. (2018). A review of Backward-Facing Step (BFS) flow mechanisms, heat transfer and control. Thermal Science and Engineering Progress 6, 194
  3. Eaton J. K. & Johnston J. P. (1981). A Review of Research on Subsonic Turbulent Flow Reattachment. AIAA Journal 19 (9), 1093-1100
  4. Graziani A., et.al. (2017). Scaling and flow dependencies over forward-facing steps. International Journal of Heat and Fluid Flow 67, 220
  5. Jovic S. & Driver D. (1994). Reynolds number effect on the skin friction in separated flows behind a backward-facing step. Experiments in Fluids 18 (6), 464-467
  6. Nadge P. M., & Govardhan R. N. (2014). High Reynolds number flow over a backward¬-facing step: structure of the mean separation bubble. Experiments in Fluids 1657(55), 1-22
  7. Nie J. H. & Armaly B. F. (2002). Three-dimensional convective flow adjacent to backward-facing step effects of step height. International Journal of Heat and Mass Transfer 45, 2431-2438
  8. Nie J. H. & Armaly B. F. (2004). Reverse flow regions in three-dimensional backward-facing step flow. International Journal of Heat and Mass Transfer 47, 4713-4720
  9. Ötügen M. V. (1991). Expansion ratio effects on the separated shear layer and reattachment downstream of a backward¬-facing step. Experiments in Fluids 10, 273-280
  10. Swift K. M. (2009). An Experimental Analysis of the Laminar Separation Bubble At Low Reynolds Numbers. Master Thesis, University of Tennessee

Last update:

No citation recorded.

Last update:

No citation recorded.