In connection with the design of wind turbines and their control algorithms, the transient loads, especially generated by time varying blade loads, are very important. In the Blade Element Momentum method, the most widespread tool in the wind turbine industry, the time constants necessary to describe these problems are not an inherent part of the model. In the present study two different approa...

Abstract. One promising design solution for increasing the efficiency of modern horizontal axis wind turbines is installation curved tip extensions. However, introducing such complex geometries may move traditional aerodynamic models based on blade element momentum (BEM) theory out their range applicability. This motivated present work, where a swept shape investigated by means both experimenta...

Efficient extraction of interconnect parasitic parameters has become very important for present deep submicron designs. In this paper, the improved boundary element method (BEM) is presented for 3D interconnect resistance extraction. The BEM is accelerated by the recently proposed quasi-multiple medium (QMM) technology, which quasicuts the calculated region to enlarge the sparsity of the overal...

Harnessing renewable and clean energy resources from winds tides are promising technologies to alter the high level of consumption traditional because their great global potential. In this regard, developing farms with multiple converters is interest due skyrocketing demand for sustainable resources. However, numerical simulation these during planning phase might pose challenges, most significa...

This paper shows a method to compute the chord and twist distributions in wind power blades. The distributions are computed to maximize the mean expected power depending on the Weibull wind distribution at a specific site. This approach avoids assumptions about optimal attack angle related to the ratio between the lift to drag coefficients. To optimize chord and twist distributions, an efficien...

Constant elements offer many advantages as compared with other higher-order elements in the boundary element method (BEM). With the use of constant elements, integrals in the BEM can be calculated accurately with analytical integrations and no corner problems need to be addressed. These features can make fast solution methods for the BEM (such as the fast multipole, adaptive cross approximation...

We describe a hybrid method which combines the boundary element method (BEM) and the finite element method (FEM) to compute circuit models for layout dependent capacitances. The method can handle irregularities in the stratification of the layout of the integrated circuits (IC’s). New in the method are the models for the interface between the regions where the BEM and the FEM are applied. We sh...

During their operation, wind turbine blades are eroded due to rain and hail, or they are contaminated with insects. Since the relative inflow velocity is higher at the outer than at the inner part of the blades, erosion occurs mostly at the outer blade region. In order to prevent strong erosion, it is possible to install a leading edge protection, which can be applied to the blades after the in...

Accurate and eecient extraction of parasitic resistance is gaining more and more importance to achieve a high-speed high-performance digital system. In this paper , we proposed a superconvergence accelerated boundary element method (SA-BEM) to calculate parasitic resistances. Experimental results show that the SA-BEM can achieve up to two orders of magnitude speed up over the traditional BEM an...

a classical theory is developed which calculates the momentum transfer rate constant between an ion and a non-polar molecule. the model takes into consideration the effect of diffraction outside the capture limit on the rate constants. the theory is used to calculate momentum transfer rate constant for cl- with trans-dichloroethylene and para-difluorobenzene. theoretical results are compared to...