Numerical Simulation Of The Natural Convection In Channels Under Complex Conditions

In recent years, as the development of the computer technology, more intensive and more complex electronic packaging are required, while natural convection has evident advantage in other cooling ways benefited from its low power, low noise and high stability. Therefore, carrying on the researches on the natural convective heat transfer characteristics of electronic devices channel under complex considerations and the prediction method of maximum temperature and heat transfer coefficient under a variety of factors, are very important to thermal design of electronics cooling.The thermal control design about electronic devices as the application background are used, and impact of different conditions and structure of the channel to the heat transfer are carried out. This article studied the natural convection heat transfer characteristics of the two-dimensional single-channel with protruding discrete heat sources and multi-channel in an closed enclosure with the assistance of CFD software FLUENT. More details are as followed:(1) The typical single-channel of convective heat transfer model is established, including geometric modeling, meshing and boundary conditions. The impact of different factors including channel aspect ratio, angle, distance, location and size between the heat sources, fluctuating heat sources on the coupled heat transfer in channel are computed.(2) Through the steady-stated convective heat transfer's simulation on the periodic single-channel, the impact on the channel heat transfer when the gas properties change as the different temperature are considered and the exponential relationship about non-dimension maximal temperature and Gr number are amended.(3) Based on procedure about the natural convection of dual-channel in closed cavity with insulated top and bottom sides and cooled right and left sides, according to numerous simulations, the impacts of low pressure, large acceleration of gravity, flow block, the channel location and other factors are analyzed. Also the interactions between channels are studied and the best locations of the heat sources are analyzed. At the same time, the impact of radiation are considered, and channel spacing, PCB board enclosure thermal conductivity and other factors on the impact of multi-channel which considered radiation, and compared the temperature difference inside the channel with radiation and without radiation. Through simulation studying, the knowledge and numerical results obtained by this research can provided a valuable reference to the conjugate heat analysis of the cooling on electronic devices and the reliability thermal design.