Conjugate natural convection combined with surface thermal radiation in an air filled cavity with internal heat source

Experimental and numerical investigations on optimal distribution of heat source array under natural and forced convection in a horizontal channel

Heat source layout optimization in two-dimensional heat conduction using simulated annealing method

Heat source layout optimization for two-dimensional heat conduction using iterative reweighted L1-norm convex minimization

The paper aims to investigate numerically the mixed convection heat transfer characteristics from seven non-identical IC chips (Aluminium) mounted on a Switch Mode Power Supply (SMPS) board (substrate) made by FR-4 (glass-reinforced epoxy laminate material). The objective is to determine the optimum configuration of these IC chips positioned at different locations on the substrate board. The optimum configuration is proposed by defining a non-dimensional geometric distance parameter ( λ ) and by employing a hybrid strategy (collaborating Artificial neural network (ANN) and Genetic algorithm (GA)). 3D, steady state numerical simulations are carried out using ANSYS Icepak to determine the temperature distribution of the IC chips. It has been confirmed that, the temperature of the IC chips strongly rely on their shape, size, and location on the substrate board. The hybrid optimization is the most robust technique to predict the arrangement of the IC chips on the substrate board more accurately, as compared to conventional methods.

Numerical investigation on optimal arrangement of IC chips mounted on a SMPS board cooled under mixed convection

Steady state experiments are conducted in a low speed horizontal wind tunnel under mixed convection for five discrete heat sources (aluminum) of nonidentical sizes arranged at different positions on a substrate board (bakelite) to determine the optimal configuration. The optimal configuration is one for which the maximum temperature excess (difference between the maximum temperature among the heat sources of that configuration, and the ambient temperature) is the lowest among all the other possible configurations and is determined by a heuristic nondimensional geometric parameter λ. The maximum temperature excess is found to decrease with λ, signifying an increase in heat transfer coefficient. In view of this, the configuration with highest λ is deemed to be the optimal one. The effect of surface radiation on the heat transfer characteristic of heat sources is also studied by painting their surface with black, which reduces their temperature by as much as 12%. An empirical correlation is developed for the nondimensional maximum temperature excess (θ) in terms of λ, by taking into account the effect of surface radiation. The correlation when applied for highest λ of the configuration returns the minimum value of θ at the optimal condition, which is a key engineering quantity that is sought in problems of this class.

Optimal Distribution of Discrete Heat Sources Under Mixed Convection—A Heuristic Approach

Experiments have been conducted for natural convection heat transfer from protruding discrete heat sources, mounted at different positions on a substrate, to determine the optimal configuration, and to study the effect of surface radiation on them, which reduces their temperature upto 12 %. The optimal configuration has been determined by a non-dimensional geometric distance parameter (λ). An empirical correlation has been proposed between the non-dimensional steady state temperature (θ) and λ, by taking into account the effect of surface radiation heat transfer.

Effect of surface radiation heat transfer on the optimal distribution of discrete heat sources under natural convection

This paper reports the results of an experimental investigation of fluid flow and heat transfer carried out with square jets issuing from perforated nozzles. This is accomplished by an impinging square jet on a uniformly heated plate of finite thickness (5 mm). The medium under consideration is air. Three different nozzle configurations are used in the study namely a single nozzle and perforated nozzles with four and nine holes, which are accommodated in the same available jet area 4.6 mm × 4.6 mm. This arrangement is akin to introducing a wire mesh at the nozzle exit plane. The effects of dimensionless jet-to-plate distance (2–9) and the mass flow rate of the jet fluid on the heat transfer rate are studied. Jet centerline mean velocity and turbulence intensity measurements are made with a hot-wire anemometer. The pressure drop across the orifice nozzle plate is measured and corresponding pumping power values are calculated. A comparison of the heat transfer performance and pumping power penalty of the three nozzle configurations is done.

Experimental investigation on heat transfer from square jets issuing from perforated nozzles

Experimental investigation on the effect of wire mesh at the nozzle exit on heat transfer from impinging square jets

Steady state experiments are conducted in a low speed horizontal wind tunnel under mixed convection regime, for five discrete heat sources (Aluminum) of different sizes arranged at different positions on a substrate board (Bakelite), to determine the optimal configuration. The characteristic length of heat sources varies from 0.005 to 0.011 m. The optimal configuration is one whose maximum temperature excess (temperature difference between the heat source and ambient) is minimum among all the possible configuration of heat sources mounted on the substrate board, and is determined by a heuristic non-dimensional geometric parameter λ. The maximum temperature excess is found to decrease with λ, signifying an increase of heat transfer coefficient. In view of this, configuration with the highest λ value is the optimal one. The effect of surface radiation on the heat transfer characteristic has also been studied by painting the surface of heat sources with black paint, which reduces their temperature by as much as 12%. An empirical correlation is developed for the non-dimensional temperature excess (θ) by taking into account the effect of surface radiation. The correlation when applied for the highest λ to the configuration, returns the maximum value of θ at the optimal value, which is a key engineering quality that is sought in problems of this class.© 2013 ASME

S. P. Venkateshan

Papers

Optimal Distribution of Discrete Heat Sources Under Mixed Convection—A Heuristic Approach

Effect of surface radiation heat transfer on the optimal distribution of discrete heat sources under natural convection

Experimental investigation on heat transfer from square jets issuing from perforated nozzles

Experimental investigation on the effect of wire mesh at the nozzle exit on heat transfer from impinging square jets

Optimal Distribution of Discrete Heat Sources Under Mixed Convection: A Heuristic Approach