Modeling of multidimensional heat transfer in a rectangular grooved heat pipe


Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Makina Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2014

Öğrenci: GÜLNİHAL ODABAŞI

Danışman: ZAFER DURSUNKAYA

Özet:

Heat pipes are generally preferred for electronics cooling application due to large heat transfer capacity in spite of small size. Micro heat pipes use small channels, whose dimension is on the order of micrometers, to generate necessary capillary action maintaining fluid flow for heat pipe operation. In the present study a flat micro heat pipe with rectangular cross section is analyzed numerically. A simplified axial fluid flow model is utilized to find liquid-vapor interface shape variation along the heat pipe axis through Young-Laplace equation. Three dimensional steady heat transfer model both in solid and fluid domain is coupled with flow equation. A coordinate transformation is applied for the heat transfer analysis in fluid domain, since the physical domain has an irregular shape along the heat pipe axis. Phase change heat transfer is introduced to the study as a boundary condition, where evaporation and condensation models at the liquid-vapor interface are solved. Heat transfer equation in liquid domain includes convection, which is generally neglected and the effect of the convection on heat pipe performance is investigated. The study is performed to investigate the effect of physical dimension of heat pipe and boundary condition on the performance of the heat pipe. Also a sample study simulating the cooling of an electronic component is conducted to define the groove size according to the defined maximum operating temperature.