Control of turbulent transport

Less friction and more heat transfer

Nobuhide Kasagi, Yosuke Hasegawa, Koji Fukagata, Kaoru Iwamoto

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Citations (Scopus)

Abstract

Because of the importance of fundamental knowledge on turbulent heat transfer for further decreasing entropy production and improving efficiency in various thermo-fluid systems, we revisit a classical issue whether enhancing heat transfer is possible with skin friction reduced or at least not increased as much as heat transfer. The answer that numerous previous studies suggest is quite pessimistic because the analogy concept of momentum and heat transport holds well in a wide range of flows. Nevertheless, the recent progress in analyzing turbulence mechanics and designing turbulence control offers a chance to develop a scheme for dissimilar momentum and heat transport. By reexamining the governing equations and boundary conditions for convective heat transfer, the basic strategies for achieving dissimilar control in turbulent flow is generally classified into two groups, i.e., one for the averaged quantities and the other for the turbulent fluctuating components. As a result, two different approaches are discussed presently. First, under three typical heating conditions, the contribution of turbulent transport to wall friction and heat transfer is mathematically formulated, and it is shown that the difference in how the local turbulent transport of momentum and that of heat contribute to the friction and heat transfer coefficients is a key to answer whether the dissimilar control is feasible. Such control is likely to be achieved when the weight distributions for the stress and flux in the derived relationships are different. Secondly, we introduce a more general methodology, i.e., the optimal control theory. The Fréchet differentials obtained clearly show that the responses of velocity and scalar fields to a given control input are quite different due to the fact that the velocity is a divergence-free vector while the temperature is a conservative scalar. By exploiting this inherent difference, the dissimilar control can be achieved even in flows where the averaged momentum and heat transport equations have the same form.

Original languageEnglish
Title of host publication2010 14th International Heat Transfer Conference, IHTC 14
Pages309-324
Number of pages16
Volume8
DOIs
Publication statusPublished - 2010
Event2010 14th International Heat Transfer Conference, IHTC 14 - Washington, DC, United States
Duration: 2010 Aug 82010 Aug 13

Other

Other2010 14th International Heat Transfer Conference, IHTC 14
CountryUnited States
CityWashington, DC
Period10/8/810/8/13

Fingerprint

Friction
Heat transfer
Momentum
Turbulence
Skin friction
Control theory
Heat transfer coefficients
Turbulent flow
Mechanics
Entropy
Boundary conditions
Fluxes
Heating
Fluids
Hot Temperature
Temperature

ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes

Cite this

Kasagi, N., Hasegawa, Y., Fukagata, K., & Iwamoto, K. (2010). Control of turbulent transport: Less friction and more heat transfer. In 2010 14th International Heat Transfer Conference, IHTC 14 (Vol. 8, pp. 309-324) https://doi.org/10.1115/IHTC14-23344

Control of turbulent transport : Less friction and more heat transfer. / Kasagi, Nobuhide; Hasegawa, Yosuke; Fukagata, Koji; Iwamoto, Kaoru.

2010 14th International Heat Transfer Conference, IHTC 14. Vol. 8 2010. p. 309-324.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Kasagi, N, Hasegawa, Y, Fukagata, K & Iwamoto, K 2010, Control of turbulent transport: Less friction and more heat transfer. in 2010 14th International Heat Transfer Conference, IHTC 14. vol. 8, pp. 309-324, 2010 14th International Heat Transfer Conference, IHTC 14, Washington, DC, United States, 10/8/8. https://doi.org/10.1115/IHTC14-23344
Kasagi N, Hasegawa Y, Fukagata K, Iwamoto K. Control of turbulent transport: Less friction and more heat transfer. In 2010 14th International Heat Transfer Conference, IHTC 14. Vol. 8. 2010. p. 309-324 https://doi.org/10.1115/IHTC14-23344
Kasagi, Nobuhide ; Hasegawa, Yosuke ; Fukagata, Koji ; Iwamoto, Kaoru. / Control of turbulent transport : Less friction and more heat transfer. 2010 14th International Heat Transfer Conference, IHTC 14. Vol. 8 2010. pp. 309-324
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