the shape of wake behind a wind turbine is normally assumed to have a hat shape for the models used in wind farm layout optimization purposes; however, it is know from experimental tests and numerical simulations that this is not a real assumption. in reality, the results of actual measurements and detailed numerical simulation show that the velocity in wake region has a s-shape profile. the pr...

The triboelectric nanogenerator (TENG) is a powerful approach toward new energy technology, especially for portable electronics. A theoretical model for the sliding-mode TENG is presented in this work. The finite element method was utilized to characterize the distributions of electric potential, electric field, and charges on the metal electrodes of the TENG. Based on the FEM calculation, the ...

In this paper the Semi-Analytical Finite Element (SAFE) method for modeling guided wave propagation is extended to account for linear viscoelastic material damping. Linear viscoelasticity is introduced by allowing for complex stiffness constitutive matrices for the material. Dispersive characteristics of viscoelastic waveguides, such as phase velocity, attenuation, energy velocity and cross-sec...

Guided wave focusing has been developed as a promising technique for defect detection in pipeworks, where non-axisymmetric flexural modes are tuned so that ultrasonic energy can be focused at a target point in a pipe. If a defect is located at the target point, large amplitude reflected waves can be observed. In this study, the focusing phenomenon is analyzed using a semi-analytical finite elem...