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A systematic procedure of experiments, performing simulation in conjunction with work measurement techniques, is introduced and aimed at undergraduate students in Industrial Engineering (IE) to learn a basic procedure for designing and implementing takt production in terms of the Toyota Production Systems (TPS). Students are split into small groups in a class. A series of experiments is designed and performed for an assembly line of magnetic contactors. Using the concept of the TPS, students perform work measurement studies including time study, process design, such as line balancing, and execute simulation experiments. At the end of the course, the teaching staff evaluates each group based on the performance of the simulation results. [ABSTRACT FROM AUTHOR]

This paper presents our study on differential pressure sensors realized with magnetic liquids. We illustrate our work using a "U" tube type magnetic liquid sensor model and the corresponding experimental setup. Three major efforts are: developing the mathematical model describing the dynamic characteristic of the sensor based on the first law of thermodynamics, conducting FE simulation of electromagnetic field with magnetic liquids, and performing experimental implementation and examination using a non-magnetic based differential pressure sensor purchased. Experimental observation indicates a good agreement between the step-response and random response given by the developed magnetic liquids based sensor and the purchased non-magnetic liquids based sensor. [ABSTRACT FROM AUTHOR]

The purpose of the present study is to develop a numerical model for the investigation of water waves propagating over a pair of impermeable submerged obstacles. The mathematic model is formulated by coupling solutions of the Navier–Stokes equations and transport equations for the surface elevation using the volume of fluid method. Based on a staggered computational mesh, an explicit numerical algorithm is employed with a predictor–corrector procedure of pressure and velocity field. The proposed model provides good agreement with other experimental results and validates its good performance. Regarding the spatial harmonic evolutions of various cases, it is noted that the present fluctuating mode of harmonic amplitudes exists upstream and at the gap between obstacles. The results show that the nonlinearity of propagating waves becomes stronger than the initial wave in such areas, and reveals much steeper wave profiles compared to the initial ones. The fluctuating harmonic amplitudes vary with the gap width and form two hydrodynamic cycles. The vortices play an important role in the wave reflection as they form a water column wall to reflect the incoming waves. The reflection ratio depends on the extent of vortex development near the upstream obstacle. The maximum wave reflection occurs in cases with dimensionless gap width S/L equal to 3/8 and 7/8 in this study. [ABSTRACT FROM AUTHOR]

Abstract: We propose a new multiscale simulation method which seamlessly combines the conventional molecular dynamics (MD) with the continuum mechanics formulated under the material point method (MPM). In MPM, modified interpolation shape functions are adopted to reduce artificial forces on the hierarchical background grids. The multiscale method is validated using the examples of step-like wave and wave packet propagations within a bar. The method is applicable to several kinds of potentials including the Lennard–Jones, EAM and a bonding-angle related potential for silicon. Examples of high energy Cu–Cu and Si–Si cluster impacts are presented. The evolution of displaced atoms is found to depend on the underlying lattice structures. For the case of Cu–Cu cluster impacts, stacking faults play an important role. The displaced atoms, visualized in the method of “local crystalline order”, propagate in an anisotropic manner. This implies the anisotropy in energy transformation process through multi-interactions among cluster and surface atoms. [Copyright &y& Elsevier]

Spatially evolving turbulent mixing layers are investigated in this paper using large eddy simulation. The evolutions of large vortex structures are obtained, in which the processes of vortex roll up, growth, pairing and breaking up are shown in details. The simulated flow patterns agree well with experimental visualization results. Predicted results of mean properties of streamwise velocity, fluctuating velocity and Reynolds stress at different sections show good self-similarity and agree well with experimental measurements. Linear growth of the momentum thickness along the streamwise direction is then obtained, indicating that pairing and amalgamating of large vortex structures in plane mixing layers occur randomly in space and time. The effects of convection velocity and the rate of shear on the evolution of vortex structures, self-similarity as well as momentum thickness are also investigated. The rate of shear has a significant effect on the evolution of coherent structure and the slope of momentum thickness growth, while the convection velocity only affects the space interval of the adjoining vortices. The rate of shear and convection velocity have no significant effect on the non-dimensional distributions of turbulence statistics. Self-similarities are therefore obtained for different rates of shear and convection velocities. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a numerical study of a gas-particle flow in three inclined rectangular jets in crossflow. The predicted gas phase velocities and particle phase velocities are validated against previously reported experimental data. Two turbulence models, the standard k–ɛ model and Shear Stress Transfer (SST) model, are used to model the gas phase turbulence. This work shows that both models provide acceptable predictions of the gas flow and mixing generated by the three jets. Neither model could accurately reproduce the jet core and the flow near bottom wall. The particle phase in this flow comprises a large number of small particles. Thus particles follow the gas phase flow closely and any errors in the turbulence model and gas flow predictions are passed on to the particle phase simulation. This paper also includes a literature review on rectangular jets in crossflow and gas-particle laden jets in crossflow. [Copyright &y& Elsevier]

A recently constructed cyclotron magnet at the Institute of Modern Physics of Chinese Academy of Sciences (IMPCAS) will be used as the injector of Heavy Ion Therapy Facility in Lanzhou (HITFiL). The diameter of the magnet is 2.92 m and its height is 1.52 m. The total weight of the magnet is 70 tons. The isochronous magnetic field for \q/m = 5/12 is achieved by appropriate pole edge profile. The paper discusses the various design and fabrication aspects of the magnet. The paper also presents the field measurement results and its comparison with simulation. [ABSTRACT FROM PUBLISHER]

Abstract: Effective nasal drug delivery is highly dependent on the delivery of drug from the nasal spray device. Atomisation of liquid spray occurs through the internal atomizer that can produce many forms of spray patterns and two of these, hollow-cone and full-cone sprays, are evaluated in this study to determine which spray pattern produced greater deposition in the middle regions of the nasal cavity. Past studies of spray particle deposition have ignored the device within the nasal cavity. Using computational fluid dynamics (CFD), two computational models of human nasal cavity model were reconstructed from CT-scans, where the difference between the two models was the presence of the nasal spray device accounting for the airway blockage at one of the nostrils. Experimental measurements from Particle Droplet Image Analyser (PDIA) were taken in order to gain confidence in determining the initial particle conditions for the computational models. An airflow field is induced through a negative pressure flow condition applied at the pharynx instead of constant flow rates at the left and the right nasal cavities. Subsequent airflow patterns and its effects on particle deposition, with and without a spray device, are compared. Contours and streamlines of the flow field revealed that the presence of a spray device in the nasal vestibule produced higher levels of disturbed flow, which helped the dispersion of the sprayed particles. Particle deposition was found to be high in the anterior regions of the nasal cavity caused by its inertia. Evaluation of the two spray types found that hollow spray cones produced more deposition in the middle regions of the nasal cavity. This paper also demonstrates the CFD methodology used, which can help in better understanding the design of future atomizers for nasal spray use. [ABSTRACT FROM AUTHOR]

Abstract: The kinetics and thermodynamics of normal grain growth can be linked by two open questions. Is it physically practicable to incorporate the grain boundary (GB) energy decrease with GB segregation into the parabolic kinetics of grain growth? Subsequently, how can a model for grain growth that considers the mixed effect of kinetics and thermodynamics be derived? Departing from Borisov’s equation, a qualitative description is provided to validate the incorporation of GB energy into the grain growth kinetics. Then, a thermokinetic model considering the mixed effect of solute drag and reduced GB energy is developed. Subjected to specific limitations, the thermokinetic model reduces to a purely kinetic model, a purely thermodynamic model and a model considering only grain-size-dependent solute drag. By application of the model to experimental results obtained from nanocrystalline Ni–P and oxygen-doped nickel, it has been shown that the effect of solute drag could retard but not stop the grain growth, and that the main cause of a stabilized nanocrystalline structure is not the solute drag but the reduction in GB energy. [Copyright &y& Elsevier]