Abstract To simulate the large-scale impacts of wind farms, turbines are parameterized within mesoscale models in which grid sizes typically much larger than turbine scales. Five wind-farm parameterizations were implemented Weather Research and Forecasting (WRF) Model v4.3.3 to multiple operational farms North Sea, verified against a satellite image, airborne measurements, FINO-1 meteorological mast data on 14 October 2017. The parameterization by Volker et al. underestimated turbulence...

Abstract. The performance of a wind farm is significantly influenced by turbine–wake interactions. These interactions are typically quantified for each turbine either measuring its nacelle speed or evaluating rotor-averaged using numerical methods that involve set discrete points across the rotor disc. Although various point distributions exist in literature, we introduce two analytical expressions integrating non-axisymmetric Gaussian wakes, which account wake stretching and shearing...

Abstract Engineering wake models enable fast calculation of wind-farm power generation including wake-turbine interactions, which is critical for annual energy yield calculations and farm optimisation either at the design phase or during operation. The operating point a turbine determined based on its rotor-averaged wind speed, impacted by upstream wakes. deficit typically calculated numerically using set averaging points across rotor disk, Gaussian shape function commonly evaluated. This...

Describing the evolution of a wind turbine's wake from top-hat profile near turbine to Gaussian in far is central feature many engineering models. Existing approaches, such as super-Gaussian models, rely on set tuning parameters that are typically obtained fitting high-fidelity data. In current study, we present new model leverages similarity between shape normal streamwise direction and diffusion passive scalar disk source. This provides an analytical expression for scaling function ensures...

Abstract. The performance of a wind farm is significantly influenced by turbine-wake interactions. These interactions are typically quantified for each turbine evaluating its rotor-averaged speed, which impacted upstream wakes, using numerical methods that involve discrete points across the rotor disk. Although various point distributions exist in literature, we introduce an analytical expression integrating Gaussian wake over circular disk, accounts stretching and shearing resulting from...

This work introduces an immersed boundary method for two-dimensional simulation of incompressible Navier-Stokes equations. The uses flow field mapping on the and performs a contour integration to calculate forces. takes into account relative location inside background grid elements by using inverse distance weights, also considers curvature edges. governing equations fluid mechanics are solved Galerkin-Least squares finite element formulation. model is validated against stationary vertically...

There is an academic discussion about the value relevance of deferred tax, which aims to find out effect tax on investors’ decisions. In light this discussion, first question impact management practices manipulate earnings, called earnings management, second third and fourth mediating management. The paper focuses listed firms in Egyptian Stock Exchange (EGX), especially that were recorded EGX 100, for six-year period (2013–2018) 107 642 completed observations. findings are as follows: uses...

This study aims to investigate the impact of corporate social responsibility (CSR) practices on debt finance (DF) Egyptian firms, as well examine moderating role accounting conservatism (AC) this relationship. The sample consists 120 listed firms from 2012 2019 with overall observations 960, data were processed using panel corrected standards errors (PCSE) and generalized least squares (GLS). results reveal that CSR have a negative effect DF means engage in less ability obtain than non-CSR...

In current calibration and compensation methods for gear backlash of industrial robots, only stationary effects are considered. Alternatively, expensive sensors used absolute position control robots. This paper investigates the dynamic behavior measurability its influences at a KUKA KR500-3 MT robot in context online compensation.

A novel method has been introduced to solve a point inclusion in polygon problem. The is applicable convex as well non-convex polygons which are not self-intersecting. independent of rounding off errors, gives it leverage over some methods prone this brief summary the used problem presented and discussed. compared other existing from view computational cost. This was inspired Computational Fluid Dynamics (CFD) application using grids fitted simulated objects.