Hysteresis Effect in Operation of Small Wind Power Generators
Mathematical models of operating of horizontal-axis and vertical-axis wind turbines (HAWTs and VAWTs) are considered describing both aerodynamic load and electric generator. This model allows describing steady regimes and transient processes. Using the model, the hysteresis phenomenon is described arising during change of the external resistance in the electric circuit. It is shown that the preferable working regimes of the devices belong to the range of external load where the hysteresis effect appears.
Analysis of Aerodynamic Hysteresis in Echelon formation
This work is based on the vortex lattice method using a “decambering” approach, which accounts for flow separation and makes the separated flow to follow viscous flow condition at high angles of attack over the airfoil and 3D wings. This method used to study the aerodynamic hysteresis of two wings configuration at near stall and post-stall flow conditions. The hysteresis of different data and their effect have been studied. The effect of shifting stall due to presence of hysteresis for forward and backward flow regimes also has been reported.
Evidence of spurious results along with spatially autocorrelated errors in the context of geographically weighted regression for two independent SAR(1) processes
AbstractThe aim of this paper is to examine the performance of the geographically weighted regression (GWR) technique in terms of recognizing linear relationships at the local level. Using a Monte Carlo analysis with two independent spatially autocorrelated SAR(1) processes, this study finds that spurious behavior exists at the local level along with spatially autocorrelated errors. Therefore, GWR estimation results must be interpreted with caution.
