Farklı boylarda sarmal şerit yerleştirilmiş eğimli boru içi akışta ısıl ve hidrodinamik performansın deneysel incelenmesi

Bu deneysel çalışmada kapsamında, 30º eğimli bir boruda ısıl olarak gelişmekte olan akış için, farklı boylardasarmal şerit kullanımının ısıl ve hidrodinamik performansa etkisi incelenmiştir. Deneyler Reynolds sayısıaralığı 500-5000, Prandtl sayısı aralığı 5-7 olacak şekilde, hatve oranı 3 ve uzunlukları 1 m (uzun) ve 0,5 m(kısa) sarmal şeritler kullanılarak yapılmıştır. Uzun sarmal şerit (USŞ) ve kısa sarmal şerit (KSŞ) kullanılandeneylerde elde edilen ısı taşınım katsayısı ve basınç kaybına bağlı Nusselt sayıları ve sürtünme faktörleritespit edilip içi boş boruda elde edilen sonuçlar ile karşılaştırılmıştır. Performans iyileştirme faktörü, USŞve KSŞ için 0,9-2,1 aralığında olup, türbülans şiddeti arttıkça birbirine yakın performans gözlemlenmiştir.Buna ek olarak Nusselt sayısı ve sürtünme faktörü için deneysel bağıntılar geliştirilmiştir. Nusselt sayısı içingeliştirilen bağıntı deney verilerini ±%13,9 ortalama sapma ile tahmin ederken, sürtünme faktörü için budeğer ±%11,9 olmuştur.

Experimental investigation of thermal and hydrodynamic performance of different length twisted tape inserts inside an inclined tube flow

In this experimental study, the effect of using different length twisted tape inserts on the thermal and hydrodynamic performance of flow in an 30° inclined tube was investigated experimentally under thermally developing flow conditions. Ranges of the experimental variables examined were: 500

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Kline S.J., McClintock F.A., Describing uncertainties in single sample experiments, Mech Eng, 75 (1), 3-8, 1953.
Gnielinski V., Heat Transfer in Pipe Flow, VDI Heat Atlas, Ed: Springer Verlag, London, 701-711, 2010.
Churchill S.W., Chu H.H.S., Correlating equations for laminar and turbulent free convection from a horizontal cylinder, Int J Heat Mass Transf, 18 (9), 1049-1053, 1975.
Eiamsa-ard S., Promvonge P., Performance assessment in a heat exchanger tube with alternate clockwise and counter-clockwise twisted-tape inserts, Int J Heat Mass Transf, 53 (7-8), 1364-1372, 2010.
Wongcharee K., Eiamsa-ard S., Friction and heat transfer characteristics of laminar swirl flow through the round tubes inserted with alternate clockwise and counter-clockwise twisted-tapes, Int Commun Heat Mass Transf, 38 (3), 348-352, 2011.
Eiamsa-ard S., Seemawute P., Wongcharee K., Influences of peripherally-cut twisted tape insert on heat transfer and thermal performance characteristics in laminar and turbulent tube flows, Exp Therm Fluid Sci, 34 (6), 711-719, 2010.
Lim K.Y., Hung Y.M., Tan B.T., Performance evaluation of twisted-tape insert induced swirl flow in a laminar thermally developing heat exchanger, Appl Therm Eng, 121, 652-661, 2017.
DU Plessis J.P., Kröger D.G., Heat transfer correlation for thermally developing laminar flow in a smooth tube with a twisted-tape insert, Int J Heat Mass Transf, 30 (3), 509-515, 1987.
Aldali Y., Elbaba I., Morad K., Heat transfer enhancement for laminar flow in circular tubes with twisted-tape inserts, J Thermophys Heat Transf, 29 (4), 805-811, 2015.
Saysroy A., Eiamsa-ard S., Periodically fully-developed heat and fluid flow behaviors in a turbulent tube flow with square-cut twisted tape inserts, Appl Therm Eng, 112, 895-910, 2017.
Man C., Lv X., Hu J., Sun P., Tang Y., Experimental study on effect of heat transfer enhancement for singlephase forced convective flow with twisted tape inserts, Int J Heat Mass Transf, 106, 877-883, 2017.
Piriyarungrod N., Eiamsa-ard S., Thianpong C., Pimsarn M., Nanan K., Heat transfer enhancement by tapered twisted tape inserts, Chem Eng Process: Process Intensif, 96, 62-71, 2015.
Man C., Yao J., Wang C., The experimental study on the heat transfer and friction factor characteristics in tube with a new kind of twisted tape insert, Int Commun Heat Mass Transf, 75, 124-129, 2016.
Yadav R.J., Padalkar A.S., CFD analysis of fully decaying, partially decaying and partly swirl flow in round tubes with short length twisted tapes, J Energy Technol Policy, 3 (1), 40-53, 2013.
Eiamsa-ard S., Thianpong C., Eiamsa-ard P., Promvonge P., Convective heat transfer in a circular tube with short-length twisted tape insert, Int Commun Heat Mass Transf, 36 (4), 365-371, 2009.
Chang S.W., Yu K., Lu M.H., Heat transfers in tubes fitted with single, twin, and triple twisted tapes, Exp Heat Transf, 18 (4), 279-294, 2005.
Eiamsa-ard S., Thianpong C., Promvonge P., Experimental investigation of heat transfer and flow friction in a circular tube fitted with regularly spaced twisted tape elements, Int Commun Heat Mass Transf, 33 (10), 1225-1233, 2006.
Jaisankar S., Radhakrishnan T.K., Sheeba K.N., Experimental studies on heat transfer and friction factor characteristics of forced circulation solar water heater system fitted with left-right twisted tapes, Sol Energy, 9 (3), 1943-1952, 2009.
Manglik R.M., Bergles A.E., Heat transfer and pressure drop correlations for twisted-tape inserts in isothermal tubes: Part II-transition and turbulent flows, J Heat Transfer, 115 (4), 890-896, 1993.
Manglik R.M., Bergles A.E., Heat transfer and pressure drop correlations for twisted-tape inserts in isothermal tubes: Part I-laminar flows, J Heat Transfer, 115 (4), 881-889, 1993.
Varun Garg M.O, Nautiyal H., Khurana S., Shukla M.K., Heat transfer augmentation using twisted tape inserts: A review, Renew Sustain Energy Rev, 63, 193- 225, 2016.