Upgrading a Shrouded Wind Turbine with a Self-Adaptive Flanged Diffuser

Abstract

In this paper, a self-adaptive flange is proposed for the wind turbine shrouded by a flanged diffuser to reduce the wind loads acting on the flanged diffuser at high wind velocities. The self-adaptive flange can maintain the advantages of the flanged diffuser at wind velocities lower than the rated velocity and reduce the wind loads acting on the diffuser and blades at higher wind velocities. Numerical analyses of fluid-structure interactions are carried out to investigate the flow field around the diffuser with a self-adaptive flange and the variation of wind load acting on the diffuser due to the reconfiguration of the self-adaptive flange at various wind velocities. Numerical results show that the wind load acting on the total flanged diffuser can be reduced by about 35% at 60 m/s due to the reconfiguration of the self-adaptive flange.

Wind Micro-Turbine Networks for Urban Areas: Optimal Design and Power Scalability of Permanent Magnet Generators

“…Different one-dimensional (1D) theoretical models have been proposed in the literature in order to predict the power production of wind turbines, with particular reference to shrouded or diffuser-augmented ones [4,[24][25][26][27]. The turbine is seen as an actuator disc and the flow over the disk is supposed to be ideal (i.e., without a rotational velocity component and frictionless).…”

“…The aforementioned power coefficient expresses the relation between the obtainable mechanical power and the power contained in the wind passing a reference area (conventionally the rotor swept area) with a given wind velocity [4]. Ducted/Shrouded Horizontal Axis Wind Turbines (S-HAWT) or Diffuser-Augmented Wind Turbines (DAWT) allow for enhancing the power output with respect to conventional or bare wind turbines, for a given rotor size [24][25][26][27]. In fact, the presence of the diffuser can provide an increase in the mass flow rate through the turbine blades, which produces a significant augmentation of the power coefficient C P referred to the rotor swept area [26].…”

“…In conclusion, the main advantages of DAWTs include the acceleration of the wind speed and the noise reduction with respect to the conventional bare turbines. The drawbacks are related to the extra weight and cost due to the presence of the diffuser; these structural and economic issues act as a restraint in the development of utility-scale wind turbines, whereas they constitute an affordable challenge for small-and micro-scale systems [24].…”

Pengaruh Desain Interior Diffuser Terhadap Peningkatan Performa Diffuser Augmented Wind Turbine (DAWT)

“…Desain kelengkungan diffuser pada curved diffuser disesuaikan dengan dimensi flat diffuser. Ketebalan diffuser yaitu 1,25 cm, mengacu pada studi terbaru yang dilakukan oleh Hu dan Wang [6], dimana pelat yang digunakan sebanyak sepuluh layer dengan ketebalan masing-pasing 1,25 mm.…”

“…Model tersebut terdiri atas kombinasi dari model standard k-ε [9] di daerah freestream dan Wilcox k-ω model [10] untuk aliran di dekat dinding. SST k-ω merupakan model turbulensi yang baik dalam hal memprediksi aliran dengan pengaruh adverse pressure gradient yang kuat sebagaimana telah digunakan pada simulasi numerik terdahulu Hu dan Wang [6], Bangga dan Sasongko [11], Bangga et al [12], Pape and Lecanu [13], Sørensen et al [14], Weihing et al [15], Jost et al [16], dan Klistafani [17,18]. Gambar Terlihat pada gambar 6 bahwa tidak ada perbedaan peningkatan kecepatan rata-rata yang dihasilkan oleh flat diffuser dengan curved diffuser pada daerah upstream hingga inlet diffuser (x/L = 0).…”