Field Synergy Mechanism And Its Application In Thermal Transport Phenomena

The enhancement and control of thermal transport is one of the top questions in the field of thermal science and energy engineering. The field synergy principle, which should be complied with for enhancing the objective exchange in the transport processes, is studied by taking convective heat transfer and heat radiation as the research subjects in this thesis. And some real transport processes are studied both theoretically and practically. First of all, the field-to-field interactions in the multi-field phenomena are studied to enhance objective transport based on the irreversible thermodynamics. The enhancing mechanism is analyzed by the phenomenological equation. The essential of objective transport is the result of field-to-field synergy and the essential to enhance the objective transport is the optimization of the field-to-field synergy. Secondly, from the viewpoint of energy equation of convective heat transfer, the field synergy principle about convective heat transfer is analyzed theoretically. The synergic optimization between flow field and temperature field makes great contributions to the enhancement of heat transfer. Then, the theoretical results are verified by numerical simulation. Moreover, a specially shaped pipe with higher heat transfer ability, named revolving ellipse duct (RED), is designed based on the field synergy principle. The flow& heat transfer in RED are numerically simulated. The excellent performance of RED is verified with the numerical simulation. Finally, the field synergy principle is introduced to heat radiation problem for the first time. Based on the research of the interaction between the incident heat radiation wave and materials, the mechanism of selective absorption of materials is revealed. The acting mechanism of radiation-to-material is the interaction between the incident heat radiation wave field and the damping oscillators field. The intensity of the interaction between the two fields is decisive for the radiation properties (absorptivity, emissivity, refractivity and reflectivity) of materials, and heat radiation performance of materials can be adjusted by the improvement of the field synergy between these two fields. This research is helpful for the popularization of the field synergy principle both theoretically and practically.