Field synergy optimization and enhanced heat transfer by a flow with multi-longitudinal vortices in tube.

*(English)*Zbl 1189.76170Summary: The field synergy equation for steady laminar convection heat transfer was derived by conditional variation calculus based on the least dissipation of heat transport potential capacity. The optimum velocity field with the best heat transfer performance and least flow resistance increase can be obtained by solving the synergy equation. The numerical simulation of laminar convection heat transfer in a straight circular tube shows that the multi-longitudinal vortex flow in the tube is the flow pattern that enhances the heat transfer enormously. Based on this result, a novel enhanced heat transfer tube, the discrete double-inclined ribs tube (DDIR-tube), is developed. The flow field of the DDIR-tube is similar to the optimal velocity field. The experimental results show that the DDIR-tube has better comprehensive heat transfer performance than the current heat transfer enhancement tubes. The present work indicates that new heat transfer enhancement techniques could be developed according to the optimum velocity field.

##### MSC:

76D55 | Flow control and optimization for incompressible viscous fluids |

76D17 | Viscous vortex flows |

80A20 | Heat and mass transfer, heat flow (MSC2010) |

80M50 | Optimization problems in thermodynamics and heat transfer |