PASİF VE AKTİF KONTROL YÖNTEMLERİ OLARAK HEM BİR AYIRICI PLAKA HEMDE PLAZMA AKTÜATÖRLER KULLANILMASIYLA DAİRESEL BİR SİLİNDİR ETRAFINDA ETKİLİ AKIŞ KONTROLÜNÜN SAĞLANMASI

Year 2021, Volume: 41 Issue: 1, 133 - 140, 30.04.2021

Hürrem Akbıyık , Yahya Akansu

https://doi.org/10.47480/isibted.979377

Cited By: 2

Abstract

Bu çalışmada, pasif ve aktif akış kontrol metotları birlikte kullanılarak bir dairesel silindir etrafındaki akış manipüle edilmiştir. Deneyler dairesel silindirin çapına bağlı (D) Reynolds sayısının 4000 ve 10000 olduğu değerlerde rüzgâr tünelinde gerçekleştirilmiştir. Pasif akış kontrol metodu olarak 3.75D uzunluğa sahip ayırıcı plaka seçilmiştir. Aktif akış kontrol metodu elemanı olarak ise plazma aktüatörler seçilmiştir ve dairesel silindirin ±90° konumuna yerleştirilmiştir. Aktif ve pasif akış kontrol yöntemleri birlikte kullanılarak, bu yöntemleri ayrı ayrı kullanılmasına göre daha büyük bir azalma elde edilmiştir. Reynolds sayısının 5000 ve 10000 olduğu değerler için hibrit yöntem, sürükleme katsayısında sırasıyla %48 ve %45 azalma sağlamıştır. Hız ölçümleri kızgın tel anemometresi kullanılarak yapılmıştır ve iz bölgesindeki hız profilleri elde edilmiştir. Akış, duman-tel yöntemi kullanılarak görselleştirilmiştir. Plazma aktüatörlü ve ayırıcı plakalı dairesel silindirin iz bölgesinin sade silindire ve ayırıcı plaka kullanılan silindirin iz bölgesine kıyasla daha dar bir genişliğe sahip olduğu sonuçlarla ortaya koyulmuştur. Ayrıca, spektral analizden, hibrit akış kontrol yöntemi kullanılarak girdap kopma frekansının önemli ölçüde baskılandığı gözlemlenmiştir.

Keywords

Dairesel silindir, Plazma aktüatör, Ayırıcı plaka, Hibrit akış kontrol, Girdap kopma frekansı

EFFECTIVE FLOW CONTROL AROUND A CIRCULAR CYLINDER BY USING BOTH A SPLITTER PLATE AND PLASMA ACTUATORS AS PASSIVE AND ACTIVE CONTROL METHODS

Abstract

In this study, passive and active flow control methods were used together to manipulate the flow around a circular cylinder. The experiments were conducted in a wind tunnel for the Reynolds number range of 4000 and 10000 based on the diameter of the circular cylinder (D). A splitter plate was used as passive flow control device and its length was chosen to be about 3.75D. Plasma actuators were placed on the circular cylinder at a position of ±90° as an active flow control device. Combining the active and passive flow control methods, a greater reduction of the drag coefficient was achieved compared to that of the cases when using these methods separately. For Reynolds numbers of 5000 and 10000, the hybrid method gives a reduction in drag of 48% and 45%, respectively. The velocity measurements were carried out by using the hot-wire anemometry and velocity profiles were obtained in the wake region. The flow was visualized by using a smoke wire method. The results revealed that the wake region of the circular cylinder with plasma actuator and splitter plate has a narrower width than the plain cylinder and with splitter plate. Also, it can be seen from spectral analysis that the vortex shedding frequency was suppressed significantly by usage of the hybrid flow control method was used.

Keywords

Circular cylinder, Plasma actuator, Splitter plate, Hybrid flow control, Vortex shedding frequency

References

• Akansu Y. E., Bayindirli C. and Seyhan M., 2016, The Improvement of Drag Force on a Truck Trailer Vehicle By Passive Flow Control Methods, Isı Bilim. Tek. Derg./Journal Of Thermal Science And Technology, 36(1), 133–141.
• Akansu Y. E., Ozmert M., and Firat E., 2011, The effect of attack angle to vortex shedding phenomenon of flow around a square prism with a flow control rod, Isı Bilim. Tek. Derg./Journal of Thermal Science And Technology, 31(1), 109–120.
• Akansu Y. E., Sarioglu M., and Yavuz T., 2004, Flow around a rotatable circular cylinder-plate body at subcritical Reynolds numbers, AIAA J., 42(6), 1073–1080.
• Akbıyık H., Akansu Y. E., and Yavuz H., 2017, Active control of flow around a circular cylinder by using intermittent DBD plasma actuators, Flow Meas. Instrum, 53, 215–220.
• Apelt C. J. and West G. S., 1975, The effects of wake splitter plates on bluff-body flow in the range 104 <R<5x105, Part 2, J. Fluid Mech., 71(1), 145–160.
• Apelt C. J., West G. S., and Szewczyk A. A., 1973, The effects of wake splitter plates on the flow past a circular cylinder in the range 104<R<5x104, J. Fluid Mech, 61(1), 187–198.
• Cimbala J. M., and Leon J., 1996, Drag of freely rotatable cylinder/splitter-plate body at subcritical Reynolds number, AIAA J., 34(11), 2446–2448.
• Durhasan T., Aksoy M. M., Pinar E., Ozkan G. M., Akilli H., and Sahin B., 2016, Vortex street suppression of a circular cylinder using perforated semi-circular fairing in shallow water, Exp. Therm. Fluid Sci., 79, 101–110.
• Ekmekci A., 2014, Circular cylinders fitted with small-scale straight and helical wires: A comparative study on the wire-induced critical effects. Exp. Therm. Fluid Sci., 53, 179–189.
• Gim O. S., Kim S. H., and Lee G. W., 2011, Flow control behind a circular cylinder by control rods in uniform stream. Ocean Eng., 38(17–18), 2171–2184.
• Güler A. A., Seyhan M., and Akansu Y. E., 2018, Effect of signal modulation of dbd plasma actuator on flow control around NACA 0015. Isi Bilim. Tek. Derg./ Journal of Thermal Science and Technology, 38(1), 95–105.
• Jukes T. N. and Choi K.S., 2009, Active control of a cylinder wake using surface plasma, In IUTAM Symposium on Unsteady Separated Flows and their Control, (pp. 539–550), Springer.
• Jukes T. N. and Choi K.S., 2009, Flow control around a circular cylinder using pulsed dielectric barrier discharge surface plasma. Phys. Fluids, 21(8), 84103.
• Messanelli F., and Belan M., 2017, A comparison between corona and DBD plasma actuators for separation control on an airfoil, In 55th AIAA Aerospace Sciences Meeting.
• Nakamura Y., 1996, Vortex shedding from bluff bodies with splitter plates, J. Fluids Struct., 10(2), 147–158. Reza-zadeh S., 2013, Investigation of fluid flow around a cylinder with EHD actuation on inclined plates behind the cylinder, In Proceedings of the 2013 International Conference on Applied Mathematics and Computational Methods in Engineering.
• Roshko A., 1961, Experiments on the flow past a circular cylinder at very high Reynolds number, J. Fluid Mech., 10(03), 345–356.
• Sarioglu M., 2016, Control of flow around a square cylinder at ıncidence by using a splitter plate, Flow Meas. Instrum., 90(462), 1–21.
• Sarıoğlu M., Seyhan M., and Akansu Y. E., 2016, Aerodynamic forces acting on a circular cylinder with splitter plate at incidence, KSÜ. Müh. Bil. Derg./Kahramanmaras Sutcu Imam University Journal of Engineering Sciences, 19(3), 1–6.
• Sung Y., Kim W., Mungal M.G., and Cappelli M.A., 2006, Aerodynamic modification of flow over bluff objects by plasma actuation, Exp. Fluids, 41(3), 479–486.
• Tabatabaeian S., Mirzaei M., Sadighzadeh A., Damideh V., and Shadaram A., 2012, Experimental investigation of the effects of various plasma actuator configurations on lift and drag coefficients of a circular cylinder including the effects of electrodes, Chinese J. Aeronaut., 25(3), 311–324.
• Thomas F. O., Kozlov A., and Corke T. C., 2008, Plasma Actuators for Cylinder Flow Control and Noise Reduction, AIAA J., 46(8), 1921–1931.