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Liquid sloshing in partially filled containers is widely observed in various engineering systems where the forces exerted by the liquid on tank walls may result in the instability of tank or even a structural failure. To enhance the hydrodynamic damping ratio and consequently decrease the sloshing forces, baffles have been designed as effective internal components inside containers in most of the practical engineering problems. In this work, we numerically investigate the sloshing mitigation using elastic baffles through our recently developed methodology based on the coupling strategy of smoothed finite element method (SFEM) and an improved version of smoothed particle hydrodynamics (SPH) offering better accuracy. First, we simulate a benchmark problem of sloshing flow interacting with an elastic baffle installed in a container, and the numerical results agree well with the experimental data. Further, various cases are conducted to study the sloshing mitigation by using deformable baffles with different configurations and elasticities. Our current observations and findings based on the simulation results demonstrate that the impact pressure on the tank wall is significantly influenced by the geometric orientations and complex configurations of elastic baffles. The timing of sloshing flow impacting on the container wall can be passively controlled by adequately choosing the baffle elasticity. The damping performances of different elastic baffles are quantified by the numerically obtained Pressure - E b a f f l e lines. The relevant analysis in this paper can greatly help explore the effective solutions to mitigate the liquid sloshing in engineering systems. • The coupling method is extended to investigate the sloshing mitigation using elastic baffles. • The coupling method obtains smooth pressure/stress fields and accurate structural deformations. • The damping effects of complex deformable baffles are comparatively studied. • The sloshing flow impacting on the container can be passively controlled by choosing the baffles. • The elastic baffles with the best damping performance are determined by the P- E b a f f l e lines. [ABSTRACT FROM AUTHOR]

This paper exploits the potential of a high-order implicit radial basis function-based differential quadrature-finite volume (IRBFDQ-FV) method for effective simulation of inviscid and viscous compressible flows using unstructured grids. The framework of IRBFDQ-FV method is based on finite volume discretization which can guarantee conservation of mass, momentum and energy. The flow field variables within each control cell are represented by a fourth-order approximation constructed by a Taylor series expansion to the cell center with spatial derivatives as the undetermined coefficients. All spatial derivatives are computed by the meshless and highly converged RBF-based differential quadrature (RBFDQ) technique. Regarding flux evaluation, the discrete gas-kinetic flux solver is applied to evaluate inviscid and viscous fluxes simultaneously for compressible viscous flows. Resultantly, the special mathematical treatment for the viscous flux, which is usually adopted in other high-order methods, can be avoided. A point extrema-based extended bounds (PEEB) shock-capturing limiter is introduced to eliminate spurious numerical oscillations near discontinuities. Due to the implicit nature of the proposed method, implicit time-stepping schemes compatible with the spatial accuracy are devised to efficiently solve the resulting discretized equations. Representative compressible flow problems are simulated to verify the high-order accuracy, excellent efficiency and robustness of the present method. Comparison with two other high-order finite volume methods further shows competitiveness of the present method in solving compressible flow problems on unstructured grids. • Compressible inviscid and viscous flow problems are solved by the present high-order method on unstructured grids. • RBFDQ meshless method is locally employed for derivative approximation. • Convective and viscous fluxes at the cell interface are simultaneously evaluated with high-order accuracy. • Implicit time integration methods are applied to obtain the steady-state and transient solutions with high-order accuracy. [ABSTRACT FROM AUTHOR]

A high-order implicit radial basis function-based differential quadrature-finite volume (IRBFDQ-FV) method is presented in this work to efficiently simulate incompressible flows with heat transfer on unstructured mesh. The velocity and temperature fields are solved by locally using the lattice Boltzmann flux solver and the high-order finite volume method. Specifically, the proposed highly accurate finite volume method utilizes a high-order Taylor polynomial to approximate the solution within every control cell. Spatial derivatives are the corresponding coefficients in the polynomial, and they are approximated by the meshless radial basis function-based differential quadrature (RBFDQ) method. The diffusive and convective fluxes at each cell interface are simultaneously evaluated through local reconstruction of lattice Boltzmann solution using D2Q9 lattice velocity model. To efficiently calculate the solution with high-order accuracy, an implicit time-marching method incorporating the lower-upper symmetric Gauss-Seidel (LU-SGS) and the explicit first stage, singly-diagonally implicit Runge-Kutta (ESDIRK) approaches is devised. The proposed method is comprehensively validated by a series of numerical experiments containing both steady-state and time-dependent heat transfer problems with/without curved boundaries at a wide variety of Rayleigh numbers and Grashof numbers. The obtained results demonstrate a high degree of accuracy and reliability of the proposed method for complex flows on unstructured mesh. In comparison with the classical second-order method, the proposed high-order method has better computational efficiency when comparable results are achieved. • A high-order IRBFDQ-FV method is presented for simulation of incompressible thermal flows on unstructured grids. • Numerical results validate the fourth-order accuracy of the present high-order method on unstructured grids. • An implicit time-marching strategy is used to compute the high-order accurate solutions for steady and unsteady flows. • The inviscid and viscous fluxes at the cell interface are simultaneously evaluated with high-order accuracy. • The present method outperforms the conventional second-order method in terms of accuracy and computational efficiency. [ABSTRACT FROM AUTHOR]

Thin-film transistors with bottom gate and staggered electrodes using radio frequency sputtering ZnO and SiO2 films as channel layer and gate insulator are fabricated in this work. The performance of ZnO-TFTs with different oxygen partial pressure (15%, 20% and 30%) SiO2 dielectrics are investigated and compared with each other. The experiment results show that the oxygen partial pressure plays an important role in enhancing both the field effect mobility and bias stability of the devices. The best performance device is obtained with 20% oxygen partial pressure SiO2 dielectric, which has the smallest leakage current compared with the other two types of insulators. The field effect mobility, on/off ratio and sub-threshold swing for the 20% oxygen partial pressure SiO2 dielectric based device are 8.1 cm2/V.s, 1.8×108 and 1.35 V/dec, respectively. The 20% oxygen partial pressure insulator based device also shows a much small threshold voltage shift of 2 V after a 20 V gate voltage stressed for 1 h, while these values for the 15% and 30% oxygen partial pressure insulator based devices are 7.3 V and 3 V, respectively. [Copyright &y& Elsevier]