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The contingency theory in quality management is examined. The comparative results of the patterns of quality management systems in selected service industries in China and in the manufacturing industry are presented.

Purpose - The aim of the study is to present a piecewise parabolic method (PPM) for numerical simulation of barotropic and nonbarotropic two-fluid flows in more than one space dimension. Design/methodology/approach - In transition layers of two components, a fluid mixture model system is introduced. Besides, conserving the mass, momentum and energy for the mixture, the model is supplemented with an advection equation for the volume fraction of one of the two fluid components to recover the pressure and track interfaces. The Tait and stiffened gas equations of state are used to describe thermodynamic properties of the barotropic and nonbarotropic components, respectively. To close the model system, a mixture equation of state is derived. The classical third-order PPM is extended to the two-fluid case and used to solve the model system. Findings - The feasibility of this method has been demonstrated by good results of sample applications. Each of the material interfaces is resolved with two grid cells and there is no any pressure oscillation on the interfaces. Research limitations/implications - With the mixture model system, there may be energy gain or loss for the nonbarotropic component on the material interfaces. Practical implications - The method can be applied to a wide range of practical problems. Originality/value - The method is simple. It not only has the advantage of Lagrangian-type schemes but also keeps the robustness of Eulerian schemes. [ABSTRACT FROM AUTHOR]

Purpose - This paper aims to examine how using lattice Boltzmann method (LBM) aids the study of the isothermal-gas flow with slight rarefaction in long microtubes. Design/methodology/approach - A revised axisymmetric lattice Boltzmann model is proposed to simulate the flow in microtubes. The wall boundary condition combining the bounce-back and specular-reflection schemes is used to capture the slip velocity on the wall. Appropriate relation between the Knudsen number and relax-time constant is defined. Findings - The computed-slip velocity, average velocity and non-linear pressure distribution along the microtube are in excellent agreement with analytical solution of the weakly compressible Navier-Stokes equations. The calculated-friction factors are also consistent with available experimental data. For simulations of slip flow in microtube, LBM is more accurate and efficient than DSMC method. Research limitations/implications - The laminar flow in circular microtube is assumed to be axisymmetric. The present LBM is only applied to the simulation of slip flows (0.01?<?Kn0<0.1) in microtube. Practical implications - Lattice-BGK method is a very useful tool to investigate the micro slip flows. Originality/value - A revised axisymmetric D2Q9 lattice Boltzmann model is proposed to simulate the slip flow in axisymmetric microtubes. [ABSTRACT FROM AUTHOR]

Purpose ? The aim of the present study is to evaluate the accuracy and efficiency of Lattice-BGK (LBGK) method application in simulation of the 3D flow through complex geometry. On the other hand, the steady flows through vascular tube with Reynolds number 10-150 and different constriction spacing ratios are simulated. Design/methodology/approach ? The numerical method is based on the LGBK method with an incompressible D3Q19 model. To treat the curved boundary, the ?bounce back? scheme combined with spatial interpolation of second order is applied. Findings ? The highly axisymmetric property in the direct 3D tube flow simulation is observed. Solutions obtained from LBGK method are quite consistent with that of finite volume method (FVM). The overall order of accuracy of these LBGK solutions is about 1.89. The LBGK incompressible D3Q19 model with the curved boundary treatment can handle the problems of 3D steady flow through complex geometry. Research limitations/implications ? Investigating the flow in constricted vascular tubes with different stenose shape and higher Reynolds number is left for future work. Practical implications ? Lattice BGK method is the very useful tool to investigate the steady vascular flow. Originality/value ? Applying LBGK method with incompressible D3Q19 model to simulate the steady flow through complex geometry. The accuracy and efficiency of the present LBGK solver are examined. [ABSTRACT FROM AUTHOR]

A detailed analysis on the characteristics of laminar flow over a bell-shaped stenosis for a physiological pulsatile flow is presented in this study. In order to have a good understanding of the physiological pulsatile flow, a comparison of the numerical solutions to three types of pulsatile flows, including a physiological flow, an equivalent pulsatile flow and a pure sinusoidal flow, are made in this work. The comparison shows that the flow behavior cannot be properly estimated if the equivalent or simple pulsatile inlet flow is used in the study of flow fields through stenosed arteries instead of actual physiological one. Then the physiological pulsatile flow is further studied by considering the effect of constriction ratio of stenosis, Womersley number and Reynolds number on the flow behavior through stenosed arteries. The analysis shows that the variation of these flow parameters puts significant impacts on the pulsatile flow field for the physiological flow. [ABSTRACT FROM AUTHOR]

Numerical studies are carried out to investigate the liquid-lubricated herringbone-grooved journal bearings (HGJBs) performance (such as the pressure and cavitation distribution, load capacity and attitude angle, stability, etc.). Symmetrical and non-symmetrical HGJBs are studied, respectively, and the herringbone grooves' influence on the stability of HGJBs is analyzed carefully. It was found that the maximum pressure and load capacity increase with the increase of eccentricity ratio while the attitude angle decreases with the increase of eccentricity ratio. The cavitation may occur in the fluid film of journal bearings while the eccentricity ratio increases to some critical value. The area of cavitated region increases with the increase of the eccentricity ratio. For non-symmetrical HGJBs, the pressure and cavitation distribution is asymmetrical oo. [ABSTRACT FROM AUTHOR]