Efficient Temporal Third/Fourth-Order Finite Element Method for a Time-Fractional Mobile/Immobile Transport Equation with Smooth and Nonsmooth Data

In recent years, the numerical theory of fractional models has received more and more attention from researchers, due to the broad and important applications in materials and mechanics, anomalous diffusion processes and other physical phenomena. In this paper, we propose two efficient finite element schemes based on convolution quadrature for solving the time-fractional mobile/immobile transport equation with the smooth and nonsmooth data. In order to deal with the weak singularity of solution near t=0, we choose suitable corrections for the derived schemes to restore the third/fourth-order accuracy in time. Error estimates of the two fully discrete schemes are presented with respect to data regularity. Numerical examples are given to illustrate the effectiveness of the schemes.

Flow blockage in a transonic axial flow compressor: simulation analysis under distorted conditions

Today the aircraft industry is looking for faster and safer engines for both civil and military applications. The performance of all different types of air breathing engines depends on the amount of mass flow rate of air entering and hot gas ejecting out from the engine. Thrust is the key role for any engine performance. To achieve more thrust all the turbo machinery components like axial fan, axial flow compressor and axial flow turbine should function effectively. This paper is primarily dealing about one of the turbo machinery component, axial flow compressor performance where the study is more focused on flow blockage formation under distorted phenomena. The complete blade boundary layer formation and related flow numerical theory are discussed in detail, accordingly the boundary conditions were set to have better numerical simulations using ANSYS tool. To find the flow blockage formation suitable turbulence model was coded using the well know compressible equations. The flow blockage between the rotor and stator of the compressor stage was calculated and also validated with that of experimental data effectively. The flow simulation results also revealed that the performance parameters under the modern engine transonic speed from Mach 0.8 to 1.2 under the distorted conditions are better for aeromechanical features.

Rock-Concrete Joints Reliability during Building Process of Super Dam

Super dam construction under high steep slope is threatened by the uncertainty of shear strength development of rock-concrete joints. With numerical theory, the shear stress vector distribution of interface was studied. The simulation results show that dam section 23 of Xiluodu arch dam has enough safety reservation at rock-concrete joints zones with 4-lift separate pouring.

Analysis of the Pressure and Carrying Capacity of the Friction Pair Fluid-Film for the High Parameter Bellows Mechanical Seal

In this research, by based on the computational fluid dynamics (CFD) numerical theory, using the Standard-Turbulence model and the Standard-Wall function, the fluid-film between the clearance of the sealing ring friction pair for the bellows mechanical seal under such the high-temperature, high-pressure, high-speed as complex working conditions was numerically simulated, the pressure fluid and the relationship of the carrying-capacity of the fluid-film between the pressure inlet of seal cavity and the width of the fluid-film, and the results of the numerical analysis was compared with the theoretical value. The researching results provide the scientific basis for the optimization designing of the high parameter bellows mechanical seals.

Research on Optimal Weight Choice of Multi-MEMS Gyroscope Data Fusion

The performance of MEMS gyroscope is crucial to its application, and the zero-bias stability is the main characteristic parameter of gyroscope performance. When fusing several outputs of similar MEMS gyroscope, we often use the weighted mean method. The weight has great influence on the fusing result. In this paper, the optimal weight choice used in the fusion of Multi-MEMS gyroscope data is derived based on multivariate numerical theory. Experimental results show that after simulating multi-MEMS gyroscope data fusion on the measurement result of several gyroscopes, the zero-bias stability will effectively improve.

Orthogonal Design Optional Method of the Numerical Theory for the Hydraulic Squeeze Parameters

To apply the orthogonal design to confirm the optimal combination parameter of hydraulic squeeze is one good method for the coal seam in a state of stable geological factors. But if so the effect of injection meets uncertainly the requirement of the project in pace with advancement of the hydraulic squeeze measure and changing of the geological factors.In view of this situation and the characteristic of qualitative variable as well as quantitative variable of the geological factors affecting hydraulic squeeze. Put forward the application of numerical theory on the basis of optimization study of orthogonal design to confirm the optimal combination of the technical parameters of hydraulic extrusion when geological factors is in precarious state and then proceed optimization study.

Numerical theory of accretion flow and jet launching: A study on the galactic center

We obtained the first spectral predictions from a simulation of the Galactic Center to include radiative processes internally. We performed simulations with and without cooling, with and without spin, and for different initial configurations of the magnetic field, in order to test the effect on jet launching and inner accretion disk characteristics. By exploring parameter space, we will attempt to place new constraints on the controversial question about the presence or not of a jet from Sgr A*, as well as study jet launching in general. We have shown that, as expected, the spin of the BH affects the structure of the jet. The presence of cooling also strongly influences the inner structure of the accretion disk and therefore affects jet launching. These results show that radiative cooling is not negligible, as is usually assumed for the very underluminous supermassive BH, Sgr A*. On the contrary, the inclusion of cooling has a very visible influence on the accretion disk. Furthermore it creates an important difference in the resulting spectra.