Effect of Vortex Generators on NREL Wind Turbine: Aerodynamic Performance and Far-Field Noise

Passive flow separation control with vortex generators (VG) is actively used over the wind turbine blade. In this paper, the effect of vortex generators is simulated on a full-scale 2-blade wind-turbine tested at the National Renewable Energy Laboratory. The simulation is performed using Very-Large-Eddy/Lattice-Boltzmann method (VLES/LBM). The analysis focuses on the effect of vortex generators on the aerodynamic performance and far-field noise. The simulation results without vortex generators are compared with the experimental results, reaching good agreement. The vortex generators produce counter-rotating vortices in the wake which effectively delay flow separation, leading to better aerodynamic performance. The acoustic analysis indicates that the dominant noise sources are the tonal noise produced by the flow separation and the turbulent-boundary-layer trailing-edge noise. Similar noise levels are obtained for the configurations with and without vortex generators

Life-long tailoring of management for patients with hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common genetic heart disease, characterised by complex pathophysiology and extensive genetic and clinical heterogeneity. In most patients, HCM is caused by mutations in cardiac sarcomere protein genes and inherited as an autosomal dominant trait. The clinical phenotype ranges from severe presentations at a young age to lack of left ventricular hypertrophy in genotype-positive individuals. No preventative treatment is available as the sequence and causality of the pathomechanisms that initiate and exacerbate HCM are unknown. Sudden cardiac death and end-stage heart failure are devastating expressions of this disease. Contemporary management including surgical myectomy and implantable cardiac defibrillators has shown significant impact on long-term prognosis. However, timely recognition of specific scenarios – including transition to the end-stage phase – may be challenging due to limited awareness of the progression patterns of HCM. This in turn may lead to missed therapeutic opportunities. To illustrate these difficulties, we describe two HCM patients who progressed from the typical hyperdynamic stage of asymmetric septal thickening to end-stage heart failure with severely reduced ejection fraction. We highlight the different stages of this complex inherited cardiomyopathy based on the clinical staging pro-posed by Olivotto and colleagues. In this way, we aim to provide a practical guide for clinicians and hope to increase awareness for this common form of cardiac disease

Molecular Monitoring of Lymphoma

This chapter provides the background information of the PCR targets for molecular MRD monitoring (i.e., Ig/TCR gene rearrangements and chromosome aberrations), explains how these targets can be identified. [...

Molecular Monitoring of Lymphoma

This chapter provides the background information of the PCR targets for molecular MRD monitoring (i.e., Ig/TCR gene rearrangements and chromosome aberrations), explains how these targets can be identified. [...

Provision of social support by mayors in times of crisis: a cross-sectional study among Dutch mayors

Security and Global Affair