On the Improvement of Wind Power Predictions Based on Terrain Characteristics and Measurements of the Annual Energy Production

The assessment of the production capacity of wind farms is a crucial step in wind farm design processes, where a poor assessment can cause significant economic losses. Data from Canadian wind farms benefiting from national production incentive programs show that wind farms are typically characterized by an overestimation of the production capacity. In this context, a study has been done to provide insight on the origin of the discrepancies between the energy production estimates and the measured energy generation, and to develop a method to reduce these discrepancies. To this end, the WAsP and MS-Micro models have been studied. Besides the wind speed measurements, topography indices have been developed to identify the influence of the various characteristics of the site on the error in the annual energy production (AEP). In addition, roughness classes have been created, including a reference roughness and a roughness complexity. The indices have also allowed establishing correlations and developing equations to evaluate the error based on the site characteristics and the positions of wind turbines on the measured annual energy production. An average reduction of up to 83% on the AEP errors was obtained when the methodology was applied to five wind farms in Canada.

Structure of Channel Flows with Surface Mounted Ribs

The flow inside a channel with surface mounted ribs is studied by numerical simulation and experimental flow visualization. Both the geometry with one rib and the geometry with two ribs, placed perpendicular to the flow, are studied, with particular emphasis on the effect of the variation of the distance between the ribs on the structure of the flow. Results show that, for Reynolds number flows of 400 and 1000 (based on the uniform incoming velocity and the height of the ribs), the flow reattaches between the ribs when they are separated by distances of 12h (h being the height of the ribs) and 6h, respectively. In this respect, however, the numerical results for the Reynolds number flow of 1000 are in contradiction with published results.

Vortex Simulation of Axisymmetrical Flows in Cylindrical Geometries．PartII：Application to Pipes Incorporating an Orifice Plate

The Random Vortex Method extended to an azisymmetrical flow is used in the study of the flow field inside pipes incorporating an orifice plate with different contraction ratios and different inlet velocity profiles. Three test-cases, each having experimental measurements available in the literature, are studied. In particular, instantaneous and average velocity fields along with the turbulent statistics for high Reynolds number flows are computed and compared to the corresponding experimental results.These comparisons show the ability and the citations of the method. The results of the numerical simulations are used in the physical analysis of the flow fields and thus allow for a better understanding of the dynamics of the flow in pipes incorporating an orifice plate.

Vortex Simulation of Axisymmetrical Flows in Cylindrical Geometries．PartI：Numerical Algorithm

The Random Vortex Method extended to an axisymmetrical flow is used in the study of the flow field inside circular geometries characterized by an axis of symmetry. The method uses a formulation in vorticity variables expressed in cylindrical coordinates with e assumption of all axisymmetrical flow.The algorithm uses a semi-Lagrangian approach for the simulation of the vortex dynamics. In this paper, the algorithm of the computational method, along with a description of the method of vorticity generation on solid walls, are presented in detail.