Analysis of Attack Angle Effect on Flow Characteristics Around Torpedo-Like Geometry Placed Near the Free-Surface via CFD

In this study, the flow characteristics of torpedo-like geometry placed near the free-surface at various angles of attack were investigated numerically. The study was carried out at the Reynolds number of Re=4x104 between immersion ratios of 0.75≤h/D≤3.5 and angles of attack α=0°,4°, 8°, and 12°. Large Eddy Simulation (LES) turbulence model was used along with the Volume of Fluid (VOF) multiphase model to investigate the effects of free-surface. Wake region had an asymmetrical structure near the free-surface as a result of the interaction. A jet-like flow region was observed between the geometry and the free-surface at lower immersion ratios due to the restriction of the flow area. This flow region had a downward movement towards the lower pressure wake region. The drag coefficient, CD, values were increased with the decrease of immersion ratio. At angles of attack α=8° and 12°, the flow separation occurring near the nose caused an additional restriction in the flow area and directed the jet-like flow toward free-surface. Variation of Froude numbers (Fr) depending on the immersion ratio is examined, and it is found that Fr number and corresponding drag coefficient have higher values for the lower immersion ratio. The free-surface effect was found negligible at h/D≥2.5 for all cases.

Analysis of Attack Angle Effect on Flow Characteristics Around Torpedo-Like Geometry Placed Near the Free-Surface via CFD

In this study, the flow characteristics of torpedo-like geometry placed near the free-surface at various angles of attack were investigated numerically. The study was carried out at the Reynolds number of Re=4x104 between immersion ratios of 0.75≤h/D≤3.5 and angles of attack α=0°,4°, 8°, and 12°. Large Eddy Simulation (LES) turbulence model was used along with the Volume of Fluid (VOF) multiphase model to investigate the effects of free-surface. Wake region had an asymmetrical structure near the free-surface as a result of the interaction. A jet-like flow region was observed between the geometry and the free-surface at lower immersion ratios due to the restriction of the flow area. This flow region had a downward movement towards the lower pressure wake region. The drag coefficient, CD, values were increased with the decrease of immersion ratio. At angles of attack α=8° and 12°, the flow separation occurring near the nose caused an additional restriction in the flow area and directed the jet-like flow toward free-surface. Variation of Froude numbers (Fr) depending on the immersion ratio is examined, and it is found that Fr number and corresponding drag coefficient have higher values for the lower immersion ratio. The free-surface effect was found negligible at h/D≥2.5 for all cases.

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Bibtex @araştırma makalesi { politeknik675632, journal = {Politeknik Dergisi}, eissn = {2147-9429}, address = {Gazi Üniversitesi Teknoloji Fakültesi 06500 Teknikokullar - ANKARA}, publisher = {Gazi Üniversitesi}, year = {2021}, volume = {24}, number = {4}, pages = {1579 - 1592}, doi = {10.2339/politeknik.675632}, title = {Analysis of Attack Angle Effect on Flow Characteristics Around Torpedo-Like Geometry Placed Near the Free-Surface via CFD}, key = {cite}, author = {Kılavuz, Alpaslan and Durhasan, Tahir and Şahin, Beşir and Kavurmacıoğlu, Levent and Akıllı, Hüseyin and Sarığıgüzel, Fuad} }
APA Özgören, M. , Kılavuz, A. , Durhasan, T. , Şahin, B. , Kavurmacıoğlu, L. , Akıllı, H. & Sarığıgüzel, F. (2021). Analysis of Attack Angle Effect on Flow Characteristics Around Torpedo-Like Geometry Placed Near the Free-Surface via CFD . Politeknik Dergisi , 24 (4) , 1579-1592 . DOI: 10.2339/politeknik.675632
MLA Özgören, M. , Kılavuz, A. , Durhasan, T. , Şahin, B. , Kavurmacıoğlu, L. , Akıllı, H. , Sarığıgüzel, F. "Analysis of Attack Angle Effect on Flow Characteristics Around Torpedo-Like Geometry Placed Near the Free-Surface via CFD" . Politeknik Dergisi 24 (2021 ): 1579-1592 <
Chicago Özgören, M. , Kılavuz, A. , Durhasan, T. , Şahin, B. , Kavurmacıoğlu, L. , Akıllı, H. , Sarığıgüzel, F. "Analysis of Attack Angle Effect on Flow Characteristics Around Torpedo-Like Geometry Placed Near the Free-Surface via CFD". Politeknik Dergisi 24 (2021 ): 1579-1592
RIS TY - JOUR T1 - Analysis of Attack Angle Effect on Flow Characteristics Around Torpedo-Like Geometry Placed Near the Free-Surface via CFD AU - Muammer Özgören , Alpaslan Kılavuz , Tahir Durhasan , Beşir Şahin , Levent Kavurmacıoğlu , Hüseyin Akıllı , Fuad Sarığıgüzel Y1 - 2021 PY - 2021 N1 - doi: 10.2339/politeknik.675632 DO - 10.2339/politeknik.675632 T2 - Politeknik Dergisi JF - Journal JO - JOR SP - 1579 EP - 1592 VL - 24 IS - 4 SN - -2147-9429 M3 - doi: 10.2339/politeknik.675632 UR - Y2 - 2020 ER -
EndNote %0 Politeknik Dergisi Analysis of Attack Angle Effect on Flow Characteristics Around Torpedo-Like Geometry Placed Near the Free-Surface via CFD %A Muammer Özgören , Alpaslan Kılavuz , Tahir Durhasan , Beşir Şahin , Levent Kavurmacıoğlu , Hüseyin Akıllı , Fuad Sarığıgüzel %T Analysis of Attack Angle Effect on Flow Characteristics Around Torpedo-Like Geometry Placed Near the Free-Surface via CFD %D 2021 %J Politeknik Dergisi %P -2147-9429 %V 24 %N 4 %R doi: 10.2339/politeknik.675632 %U 10.2339/politeknik.675632
ISNAD Özgören, Muammer , Kılavuz, Alpaslan , Durhasan, Tahir , Şahin, Beşir , Kavurmacıoğlu, Levent , Akıllı, Hüseyin , Sarığıgüzel, Fuad . "Analysis of Attack Angle Effect on Flow Characteristics Around Torpedo-Like Geometry Placed Near the Free-Surface via CFD". Politeknik Dergisi 24 / 4 (Aralık 2021): 1579-1592 .
AMA Özgören M. , Kılavuz A. , Durhasan T. , Şahin B. , Kavurmacıoğlu L. , Akıllı H. , Sarığıgüzel F. Analysis of Attack Angle Effect on Flow Characteristics Around Torpedo-Like Geometry Placed Near the Free-Surface via CFD. Politeknik Dergisi. 2021; 24(4): 1579-1592.
Vancouver Özgören M. , Kılavuz A. , Durhasan T. , Şahin B. , Kavurmacıoğlu L. , Akıllı H. , Sarığıgüzel F. Analysis of Attack Angle Effect on Flow Characteristics Around Torpedo-Like Geometry Placed Near the Free-Surface via CFD. Politeknik Dergisi. 2021; 24(4): 1579-1592.
IEEE M. Özgören , A. Kılavuz , T. Durhasan , B. Şahin , L. Kavurmacıoğlu , H. Akıllı ve F. Sarığıgüzel , "Analysis of Attack Angle Effect on Flow Characteristics Around Torpedo-Like Geometry Placed Near the Free-Surface via CFD", Politeknik Dergisi, c. 24, sayı. 4, ss. 1579-1592, Ara. 2021, doi:10.2339/politeknik.675632