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Involvement of important engineering applications in the interaction of free-moving objects with dispersed multi-phase flows are numerous in recent years. However, due to the challenge and complexity, few studies have been reported and modeling approaches remain very limited. This paper reviews the use of discrete particle models (DPMs) for the study of the fluid flow phenomena and elaborates several different types of multiple phases. The efficiency of particle retention and computational time were considered in determining the most appropriate multiphase model. Therefore, the dynamic modeling of multi-scale systems requires a method to solve the problem of structural fluid interaction (FSI) in the particle fluid flow.

The applications of porous media burners are of often keen interest to researchers because of many modern advantages, such as high thermal efficiency, stable flame and low emission rate. In this current experimental work, a microburner was made built to achieve both surface and submerged flame for three different thicknesses of reaction layers. A reaction layer of discrete alumina with a predefined thickness of preheat layer was used for combustion. Reaction layer was accordingly replaced with different thicknesses of 10mm, 20mm and 30mm. This work mainly aimed to show burner behavior with increase in thickness of reaction layer thus suggesting the optimum equivalence ratio from best burner performance. Interesting and unique behavior of the burner was encountered for each thickness of the reaction layer. Highest surface temperature was found out with 10mm of reaction layer, while highest wall temperature was incorporated with 20mm of reaction layer. Equivalence ratio of 0.3 is best suitable for optimum p...

This paper studies the three-dimensional simulation of pressurized underfill process for I-type dispensing method on a 10 by 10, middle empty ball-grid-array (BGA) using lattice-Boltzmann method. Underfill encapsulations plays an important role in increasing the reliability of a flip chip package. Pressurized underfill process is introduced to overcome the drawbacks of the usual capillary underfill process which include extended filling time, incomplete filling and the high chances of void formation. Four different pressure values are used as the input pressure in the lattice-Boltzmann simulation of the pressurized underfill process. It was shown that the high pressure region concentrates at the inlet region, while the peak pressure in the flow domain is around four times the initial input pressure.

The demands of small size electronic devices are increasing rapidly. Therefore, relatively smaller Ball Grid Array (BGA) chip package with high performance is desired. In achieving this chip minimization target, further investigation on the effect of gap height is required. Therefore, aim of this project is to study the effect of different BGA chip size and gap height on the capillary contact angle. The contact angle between the chip and encapsulant will determine the performance of encapsulation process in terms of the filling time and flow front propagation. Experimental observations are conducted for I-type dispensing on a 10x10 Middle Empty orientation of BGA models with different scale up sizes. Based on the findings, the contact angle during the filling process increases as the gap height reduces. These contact angle values will be used as an input wall adhesion angle input in the numerical simulation for various types of encapsulation process.

In the conventional underfill (CUF) encapsulation process, there are few drawbacks encountered such as extended filling time, incomplete filling and voids formation. Finite volume method (FVM) simulations have been conducted to study different CUF dispensing method for different types of ball grid array (BGA) orientations in a single-layered PCB. It is investigated that the most ideal combination of orientations and dispensing type is middle empty orientation with L-type flow achieving relatively fast filling time. The findings show that the arrangement of BGA sizes with the small solder balls placed at the bottom layer, followed by the medium size solder balls in the middle stack and the largest solder balls at the top layer has been shown to enhance the flow rate of the encapsulant. This study also reveals the potential of air gaps in improving velocity and pressure distribution near inlet and outlet to achieve faster total filling time in all layers of BGA.

In this work, an idealized artery bifurcation aneurysm model is created and fabricated. A type of stent configurations namely half-Y (6mm) is constructed and deployed in the artery model. The effect of stent placement on the flow pattern, velocity and pressure are analyzed using particle image velocimetry (PIV) measurement. Aqueous glycerol solution is used as the working fluid to mimic properties of human blood. Based on the results, the use of half-y stent managed to reduce the blood velocity flowing into the aneurysm sac by more than half. This will reduce the size of the aneurysm gradually as the flow reduces.