The effect of centrifugal mass forces on heat transfer in a spherical dimple on a surface of constant curvature

Аuthors

Shchukin A. V.^1*, Bulanov O. Y.², Il'inkov A. V.^1**, Takmovtsev V. V.^1***, V. ¹, Antropov D. N.¹

1. Kazan National Research Technical University named after A.N. Tupolev, Kazan, Russia
2. Combustion Consulting, Moscow, Russia

*e-mail: a.v.shchukin@rambler.ru
**e-mail: ailinkov@mail.ru
***e-mail: vvt379@rambler.ru

Abstract

Average heat transfer in a spherical dimple in turbulent flows was estimated from experiments. The dimple was mounted on a convex or concave surface of one-dimensional curvature, or on a flat surface. The Reynolds number, Re_d, ranged between 6·10⁵ and 60·10⁵. Comparative studies demonstrated that the average heat transfer in the spherical dimple mounted on the convex surface in turbulent flows is 20% lower than the one in the dimple located on the flat plate under otherwise equal conditions: (Nuconv/Nu0)Re ≈ 0.8. The average heat transfer in the spherical dimple on the concave surface in turbulent flows increases: (Nu_conc/Nu₀)_Re ≈ 1.3. The average heat transfer in spherical dimples differs between the convex and concave surfaces due to centrifugal mass forces. Measurements of turbulence intensity in the spherical dimple provided qualitative validation of the results of heat transfer experiments.

Keywords:

heat transfer promoter, spherical dimple, physical experiment, convex and concave surfaces, average heat transfer, turbulence intensity

References

1. Khalatov A.A., Avramenko A.A., Shevchuk I.V. Teploobmen i gidrodinamika okolo krivolineinykh poverkhnostei (Heat transfer and hydrodynamics near curved surfaces), Kyiv, Naukova dumka, 1992, 136 p.
2. Khalatov A.A. Teploobmenigidrodinamika v polyakh tsentrobezhnykh massovykh sil. Vikhrevye tekhnologii aerodinamiki v energeticheskom gazoturbostroenii. T.7 (Heat exchange and hydrodynamics in the fields of centrifugal mass forces. Vortex technologies of aerodynamics in energy gas turbine engineering. Vol.7), Kyiv, ITTF AN Ukrainy, 2008. 292 p.
3. Leont’ev A.I., Alekseenko S.V., Volchkov E.P., Dzyubenko B.V., DragunovYu.G., Isaev S.A., Koroteev A.A., Kuzma-KichtaYu.A., Popov I.A., Terekhov V.I. Vikhrevye tekhnologii dlya energetiki (Vortex technologies for energy), in Leont’ev A.I. (ed), Moscow, Izdatel’skii dom MEI, 2017. 350 p.
4. Leont’ev A.I., Olimpiev V.V., Dilevskaya I.A., Isaev S.A. Sushchestvo mekhanizma intensifikatsii teploobmena na poverkhnosti so sfericheskimi lunkami (Obzor. Analiz. Prostye modeli. Prognoz. Rekomendatsii), Izvestiya RAN. Energetika, 2002, no. 2, pp. 117–135.
5. Shchukin A.V., Il’inkov A.V., Takmovtsev V.V., Il’inkova T.A., Khabibullin I.I. Teplofizika rabochikh protsessov v okhlazhdaemykh lopatkakh gazovykh turbin (Thermophysics of working processes in cooled gas turbine blades), in Shchukin A.V. (ed), Kazan, Izd-vo KNITU, 2020. 392 p.
6. GortyshovYu.F., Popov I.A., Olimpiev V.V., Shchelchkov A.V., Kas’kov S.I. Teplogidravlicheskayaeffektivnost’ perspektivnykh sposobov intensifikatsii teplootdachi v kanalakh teploobmennogo oborudovaniya. Intensifikatsiya teploobmena: monografiya (Thermohydraulic efficiency of promising methods of heat transfer intensification in the channels of heat exchange equipment. Intensification of heat exchange: monograph), Kazan, Tsentr innovatsionnykh tekhnologii, 2009. 531 p.
7. Kiknadze G.I., Gachicheladze I.A., Alekseev V.V. Samoorganizatsiya smercheobraznykh strui v potokakh vyazkikh sploshnykh sred i intensifikatsiya teploobmassoobmena, soprovozhdayushchaya eto yavlenie (Selforganization of tornado-like jets in streams of viscous continuous media and intensification of heat and mass transfer accompanying this phenomenon), Moscow, Izdatel’stvo MEI, 2005. 84 p.