The International Journal of Multiphysics 

About: The International Journal of Multiphysics is an academic journal published by Multi-Science Publishing. The journal publishes majorly in the area(s): Finite element method & Multiphysics. It has an ISSN identifier of 1750-9548. It is also open access. Over the lifetime, 445 publications have been published receiving 1937 citations.

Numerical modeling of turbulence mixed convection heat transfer in air filled enclosures by finite volume method

Abstract: In the present study, first the turbulent natural convection and then laminar mixed convection of air flow was solved in a room and the calculated outcomes are compared with results of other scientists and after showing validation of calculations, aforementioned flow is solved as a turbulent mixed convection flow, using the valid turbulence models Standard k−e, RNG k−e and RSM. To solve governing differential equations for this flow, finite volume method was used. This method is a specific case of residual weighting method. The results show that at high Richardson Numbers, the flow is rather stationary at the center of the enclosure. Moreover, it is distinguished that when Richardson Number increases the maximum of local Nusselt decreases. Therefore, it can be said that less number of Richardson Number, more rate of heat transfer.

Mechanism of the Shock Wave Generation and Energy Efficiency by Underwater Discharge

Abstract: We are developing the rice powder manufacturing system using an underwater shock wave. The purpose of this study is to research a mechanism of the shock wave generation and energy efficiency by underwater discharge in order to increase energy of the underwater shock wave. We observed the shock wave generation using the visualization device with a high speed camera, and measured voltage current characteristics at the same time. As a result, it was clarified that countless underwater shock waves were generated at the time of water plasma expansion by discharge. But, the shock wave was not confirmed at the time of after a second peak of the damping oscillation. It was clarified that one part of charging energy was used to generation of the shock wave. Therefore, it was clarified that to release energy by the critical oscillation is desirable for efficient generation of the shock wave.

The use of pulsed high-speed liquid jet for putting out gas blow-out

Abstract: The experimental analysis of putting out a gas blow-out with the help of pulse liquid flow with high velocity, which generates by powder pulse water-cannon are carried out. The flow velocity resides in range from 300 to 600 m/s in experiments depends on charge energy. Velocity of the flow head right near the gas flame determined with the help of laser contactless measuring instrument of velocity. Photography of flow was carried out. According to the preliminary test results the hydrodynamic parameters of powder pulse water-cannon for obtaining liquid flow with depend velocity are calculated. It is shown, that around the liquid flow of high velocity in air produced fine water spray with high velocity in large cross section area that effective knock down the gas blow-out at the distance 5-20 m from installation.

A review of passive and active mixing systems in microfluidic devices

Abstract: A review of mixing elements and devices for microscale fluidic devices is presented. The application, principles and characterisation of these devices is discussed, and the classifications based on these factors highlighted. A review of published works relating both experimental and simulation profiling of both passive and active mixing systems is presented. Each mixing principle upon which a design is based is discussed with regard to the fundamental physics that governs fluid behaviour. Passive systems covered include multi-lamination, split/recombination, chaotic advection, jet based, recirculation and droplet internal convection. Active systems covered include longitudinal and transverse pulsing, micro-stirrers, electro-kinetic methods, and acoustic/ultrasonic excitation. The review shows that the majority of devices have been designed within the past five years. Furthermore, at present, devices based on the multi-laminate method appear to outperform most other systems.

Free vibration analysis of dragonfly wings using finite element method

Abstract: In the present work, investigations on the microstructure and mechanical properties of the dragonfly wing are carried out and numerical modeling based on Finite Element Method (FEM) is developed to predict Flight characteristics of dragonfly wings. Vibrational behavior of wings type structures is immensely important in analysis, design and manufacturing of similar engineering structures. For this purpose natural frequencies and mode shapes are calculated. In addition, the kind of deformation in each mode shape evaluated and the ratio between numerical natural frequency and experimental natural frequency presented as damping ratio. The results obtain from present method are in good agreement with same experimental methods.