Investigation of the Flow Structures for Two Tandem Arrangement of Torpedo-Like Geometries

Year 2022, , 135 - 155, 23.02.2022

Ezgi Akbudak , Bülent Yanıktepe , Ertuğrul Şekeroğlu , Ömer Kenan , Muammer Ozgoren

https://doi.org/10.47495/okufbed.1037969

Cited By: 2

Abstract

Experimental studies on autonomous underwater vehicles for a torpedo-like geometry are limited in the literature. In this study, flow structures of a streamlined torpedo-like geometry having an elliptical nose and tampered stern at a length to diameter aspect ratio of L/D=5 for a single and double tandem arrangement with various spacings have been investigated using Particle Image Velocimetry (PIV) method in a closed loop water channel. Reynolds number defined for length of the geometry (L=200 mm), free stream water velocity of 100 mm/s was taken as Re=20000, the spacing (G) between two identical torpedo-like geometries is changed from 0 to 120 mm. Instantaneous 1000 images and their time-averaged results are comparatively presented for all configurations of the torpedo-like geometry. It is demonstrated that the tandem arrangements depending on the dimensionless spacing ratios (G/L) between 0 to 0.6 are significantly different from the single torpedo-like geometry for the flow patterns of instantaneous and time-averaged velocity field, dimensionless streamwise velocity component and streamline topology. For the contacting case in which the following model nose is placed on the trailing-edge of the front model, wake region of the back geometry is similar to the single model wake but the all of time-averaged flow patterns elongated and symmetrical flow patterns are slightly deformed. When flow area is provided between two models for spacing ratios of 0.15≤G/L≤0.30, chaotic and rotational flow patterns occur due to the impinging separated flow patterns from the front geometry to the nose of the downstream one. As the gap distance increases to the largest value at G/L=0.6, the wake region of both the single and tandem arrangement becomes almost identical. More detailed information for the flow characteristics of the examined torpedo-like geometry can be determined by using computational fluid dynamics after validation with PIV results in the present study.

Keywords

Elliptical nose, PIV, Tandem arrangement, Torpedo-like geometry, Turbulent flow, Viscous flow

Supporting Institution

Scientific and Technological Research Council of Turkey (TUBITAK)

Project Number

214M318

Thanks

The authors would like to acknowledge the Scientific and Technological Research Council of Turkey (TUBITAK) under Contract No. 214M318 and thank the Advanced Fluid Mechanics PIV laboratory of Osmaniye Korkut Ata University, Turkey for using the water channel and measurement systems.

Torpido Benzeri Geometrilerin İki Tandem Düzenlemesi İçin Akış Yapılarının İncelenmesi

Abstract

Otonom sualtı araçları ile ilgili deneysel çalışmalar torpido benzeri bir geometri için literatürde sınırlıdır. Bu çalışmada, çeşitli aralıklarla tek ve çift tandem düzenlemesi için uzunluk-çap en boy oranı L/D=5 olan, eliptik bir burna ve konik kıç kısmına sahip aerodinamik torpido benzeri bir geometrinin akış yapıları, bir kapalı çevrim su kanalı içinde Parçacık Görüntülemeli Hız ölçme (PIV), yöntemi kullanılarak incelenmiştir. Geometrinin uzunluğu için tanımlanan Reynolds sayısı (L=200 mm) Re=20000 değeri, serbest su akış hızı 100 mm/s, olarak alındı, iki özdeş torpido benzeri geometri arasındaki mesafe (G) 0-120 mm aralığında değiştirildi. Torpido benzeri geometrinin tüm konfigürasyonları için anlık ve 1000 görüntüden hesaplanan zaman ortalamalı karşılaştırmalı olarak sunuldu. Boyutsuz boşluk oranlarına (G/L) 0 ila 0,6 arasındaki bağlı tandem düzenlemelerinin, anlık hız alanı (V), zaman ortalamalı hız alanı , boyutsuz akış yönündeki hız bileşeni ve akım çizgisi topolojilerinin <> tek torpido benzeri geometriden önemli ölçüde farklı olduğu gösterilmiştir. Öndeki modelin firar ucu arkadaki modelin burnuna temas durumu için arka geometrinin art izi bölgesi tek model art izine benzer, ancak tüm zaman ortalamalı akış yapıları uzamakta ve simetrik akış yapıları biraz deforme olmaktadır. Boyut boşluk 0,15≤G/L≤0,30 aralık oranları için iki model arasında akış alanı sağlandığında, öndeki geometriden ayrılmış akış yapılarının arkadaki geometrinin burnuna çarpması nedeniyle karmaşık ve dönümlü akış yapıları oluşur. Boşluk oranı en büyük değer G/L=0,6'ya yükseldikçe hem tekli hem de art arda düzenlemesinin art izi bölgesi hemen hemen aynı hale gelir. İncelenen torpido benzeri geometrinin akış özellikleri için daha ayrıntılı bilgi, bu çalışmadaki PIV sonuçlarıyla doğrulama yapıldıktan sonra hesaplamalı akışkanlar dinamiği kullanılarak belirlenebilir.

Keywords

Eliptik burun, PIV, Tandem düzenleme, Torpido benzeri geometri, Türbülanslı akış, Viskoz akış

Project Number

214M318

References

• Alexander RM. Hitching a lift hydrodynamically in swimming, flying and cycling. Journal of Biology 2004; vol. 3.
• Andersson M. and Wallander J. Kin selection and reciprocity in flight formation.?, Behavioral Ecology, 2004, vol. 15, no. 1, pp. 158–162.
• Cimbala JM., Nagib HM, Roshko A., Large structure in the far wakes of two-dimensional bluff bodies, J. Fluid Meeh., 1988, col. 190, pp. 265-298
• Hanrahan B. and Juanes F., Estimating the number of fish in atlantic bluefin tuna schools using models derived from captive school observations, Fishery Bulletin, 2001, vol. 99(3).
• Hossain, M. M., Nayeem, M. H. K., & Ali, M. A. T., Numerical study of flow characteristics around rectangular cylinders in tandem. Journal of Mechanical Engineering, Automation and Control Systems, 2021, 2(1).
• Husaini M., Samad Z., and Arshad MR. CFD simulation cooperative AUV motion. Indian Journal of marine Sciences. 2009; vol. 38(3), pp. 346–351.
• Ibrahim, TA., & Gomaa, A. Thermal Performance Criteria of Elliptic Tube Bundle in Crossflow. International Journal of Thermal Sciences, 2009; 48(11), 2148-2158.
• Jianfeng, Zou, et al. Wake structures of two spheres in tandem arrangement at various gaps for Re= 300. Progress in Natural Science, 2005, 15.2: 132-136.
• Kilavuz A., Ozgoren M., Durhasan T., Sahin B., Kavurmacioglu L.A., Akilli H, Sarigiguzel F., Analysis of Attack Angle Effect on Flow Characteristics Around Torpedo-Like Geometry Placed Near the Free-Surface via CFD, J Polytech. 2021; doi:10.2339/politeknik.675632.
• Mitchell MA., Delery J., Research into Vortex Breakdown Control. Progress in Aerospace Sciences 2001; 37(4), 385-418.
• Mittal S. & Kumar V., Flow-induced oscillations of two cylinders in tandem and staggered arrangements. Journal of Fluids and Structures. 2001;15(5), 717-736.
• Molland AF. and Utama IKAP., Wind tunnel investigation of a pair of ellipsoids in close proximity, Ship Science University of Southampton 1997; Tech. Rep. 98.
• Myring DF. A theoretical study of body drag in subcritical axisymmetric flow. Aeronautical quarterly 1976;27.3: 186-194.
• Ozgoren M. Flow structure in the downstream of square and circular cylinders. Flow Measurement and Instrumentation, 2006; 17.4: 225-235.
• Ozgoren M. Flow structures around an equilateral triangle arrangement of three spheres. International journal of multiphase flow, 2013; 53: 54-64.
• Ozgoren M. et al., Comparison of Different Configurations of Two Spheres at Re=5000 in a Uniform Flow. 17th International Symposiumon Applications of Laser Techniques to Fluid Mechanics Lisbon, Portugal, 2014.
• Partridge B. L., Johansson J., and Kalish J., The structure of schools of giant bluefin tuna in cape cad bay. Environmental Biology of Fishes 1983; vol. 9, pp. 253–262.
• Papaıoannou, Georgios V., et al., Three-dimensionality effects in flow around two tandem cylinders. Journal of Fluid Mechanics 2006; 558: 387-413.
• Pinar E. et al., Experimental study of flow structures around side-by-side spheres. Industrial & Engineering Chemistry Research, 2013; 52.40: 14492-14503.
• Rattanasiri P., Wilson PA. & Phillips AB., Numerical investigation of the drag of twin prolate spheroid hulls in various longitudinal and transverse configurations. In2012 IEEE/OES Autonomous Underwater Vehicles (AUV). IEEE, 2012; pp. 1-7.
• Sekeroglu E. Akarsu Uygulamasi için Bir Dikey Eksenli Su Türbininin Akış ve Güç Parametrelerinin İncelenmesi. (Master’s thesis). Osmaniye Korku Ata University Instıtute of Scıences Master’s thesis No. 592444, Osmaniye, Türkiye, 2019
• Siegel S., McLaughlin T. & Morrow J., PIV measurements on a delta wing with periodic blowing and suction. In19th AIAA Applied Aerodynamics Conference 2001; p. 2436.
• Tobak M. & Peake DJ., Topology of three-dimensional separated flows. Annual review of fluid mechanics 1982;14(1), 61-85.
• Weihs D. The hydrodynamics of dolphin drafting. Journal of Biology, 2004, vol. 3:8.
• Westerweel J. Efficient detection of spurious vectors in particle image velocimetry data. Experiments in Fluids 1994; 16.3: 236-247.
• Yagmur S. Torpido Benzeri Geometri Çevresindeki Akış Yapısının Araştırılması. Selcuk University Instıtute of Scıences Master’s thesis, No.438592, Konya, Türkiye, 2016.
• Yagmur S., et al. Experımental Investıgatıon of Attack Angle Effect on Flow Structure Around Leadıng and Traılıng Edges of a Torpedo-Lıke Geometry. Proceedıngs Book, 2016; 57.
• Yaniktepe B. & Rockwell D., Flow structure on diamond and lambda planforms: Trailing-edge region. AIAA journal 2005;43(7), 1490-1500.
• Zdravkovıch MM. Review of flow interference between two circular cylinders in various arrangements. 1977.
• Zheng Q. & Alam MM. Evolution of the wake of three inline square prisms. Physical Review Fluids 2019;4(10), 104701.
• Zobeyer H., Baki A. & Nowrin SN., Interactions between Tandem Cylinders in an Open Channel: Impact on Mean and Turbulent Flow Characteristics.Water 2021;13(13), 1718.