Disputas: Zhongyuan Shi

M.Sc. Zhongyuan Shi ved Matematisk institutt vil forsvare sin avhandling for graden ph.d.

Multi-objective Thermohydraulic Investigation on Miniaturized Channels with Constructal Law of Design  

 

Zhongyuan Shi

Tid og sted for prøveforelesning

5. april 2019 kl. 10.15, "Abels utsikt", 12. etasje, Niels Henrik Abels hus.

Bedømmelseskomité

  • Associate Professor Weimin Ma, Royal Institute of Technology (KTH)

  • Professor Carlos Alberto Dorao, Norwegian University of Science and Technology

  • Associate Professor Mikael Mortensen, Universitetet i Oslo

Leder av disputas

Professor Hans Brodersen, Matematisk institutt, Universitet i Oslo

Veiledere

  • Professor Atle Jensen, Matematisk institutt, Universitet i Oslo

  • Professor Tao Dong, Department of Microsystems, University of South-Eastern Norway

Sammendrag

 

The present work is financed by the Forskningsrådet Nærings-Ph.D. project Thermohydraulic investigation on the constructal design of micro/nano heat transfer enhancement for high-efficient thermal energy systems (No. 251129) owned by Trilobite AS.

Compromised design is of particular significance in the facilities that usually come with high rate of volumetric heat generation and require efficient heat dissipation, since the energy consumption for delivering the coolant fluid may exceed the heat removed. This is thermo-economically not favorable and is getting more severe as the space for the design of cooling system is expectably miniaturized to save more space for more functional integration (like in electronics) or higher efficiency of energy conversion (as in photovoltaics). The wall-mounted enlarging elements – the pin-fin array serve as the first exemplary case, following their most celebrated applications in aeronautical jet engines. The analysis based on the evaluated accessibility of the design to the flows of heat and fluid was challenged by the aforementioned concern of thermal economics. It was further endorsed in a later experimental observation that the higher rate of return corresponds to the lower end of all flow rates tested. Extra discretion is to be exercised in assessing the accessibilities, again respectively to heat flow and fluid flow, concerning the gap of orders of magnitude in between. The geometric design optimization, which is categorized depending on whether the enlarging elements are present or not. The former focuses on the evolution of the axial fin profile for higher fin efficiency (i.e. easier access to the heat flow)– the cone shape with an additively-rounded corner growing from where its lateral surface meets the substrate, while the practical concern on the tip angle which can be fabricated posed an additional constraint. The latter swerved to the layout of flush-mounted heat sources, where the presumed exploit of the leading edge of the boundary layer for higher heat transfer performance would not necessarily yield an overall triumph as the peak temperature and the flow friction are considered in the meantime.

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Publisert 22. mars 2019 12:10 - Sist endret 26. mars 2019 08:16