Performances and Stall Delays of Three Dimensional Wind Turbine Blade Plate-Models with Helicopter-Like Propeller Blade Tips

Abstract

The research on three dimensional (3-D) wind turbine blades has been introduced (Sutrisno, Prajitno, Purnomo, & B.W. Setyawan, 2016). In the current experiment, the 3-D wind turbine blades would be fitted with helicopter-like blade tips and additional fins to the blade hubs to demonstrate some laminarizing features.It was found that additional helicopter-like blade tip to the turbine blade creates strong laminar flows over the surface of the blade tips. Supplementary, finned hub, fitted to the blade body, creates rolled-up vortex flows, weakens the blade stall growth development, especially for blades at high-speed wind. A proposed mathematical form of modified lifting line model has been developed to pursue further 3-d blade development study of 3-d wind turbine blade.Rolled up vortex effects, developed by finned of the base hub, has been acknowledged could demolish the turbulent region, as well as laminarize the stall domain to intensify the induced wind turbine blade lift.

Dimensional Analysis in Power Predicting of a Real Scale Wind Turbine Based on Wind Tunnel Torque Measurement of Small Scaled Models

“…Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 16 August 2018 doi:10.20944/preprints201808.0283.v1 Figure 12 shows comparisons between the tuft patterns of backward wind turbine blades of radius r = 19 cm. The coefficient of performance of these two backward blades, since they both have the same styles, are similar [9]. Figure 12 showed the patterns at a) U=4.5 m/s, RPM=840, TSR=3.712, with weak stall pattern, b) U=5.2 m/s, RPM=1060, TSR=4.054, with half stall pattern, c) U=5.5 m/s, RPM=1120, TSR=4.059, similarly with half stall pattern, and the second row at d) U=3.0 m/s, RPM=200, TSR=1.325, with weak stall pattern, e) U=4.2 m/s, RPM=440, TSR=2.083, with half stall pattern, f) U=4.9 m/s, RPM=530, TSR=2.151, also with half stall pattern.…”

“…As for wind turbines, with the addition of swept on the blade, it slightly reduces performance but stall is delayed, that the blade high performance will survive, to higher wind speeds. In wind turbine blades, since stall propagation from the root outward, swept positive/backward is from the root toward the tip [9], as seen in Fig, 3. This is very beneficial for the region with lots of gusty winds.…”

“…For the results comparison between the lifting line theory and measured power, in the previous report [9], we have compared between performance coefficient (Cp) versus tip speed ratio (λ) implementing lifting line theory based on the Pistolesi principle with rotation, versus the actual measurement results. The matching result was satisfactory.…”

“…Lutz describes the practicality of lifting-line theory, Ayati calculates aerodynamic effects on wind turbine blades using the lifting-line theory, and digitally Lamar, developing a modified Multhopp approach for predicting lifting pressures and camber shape for composite planforms [6][7][8]. Moreover, Sutrisno et al, using the lifting-line theory, modeled the performances of three-dimensional (3-D) wind turbine blade plate-models with helicopter-like propeller blade tips [9]. 2 of 12 Kesler made a comparison between the experimental thrust and propeller thrust predicted by Prandtl's lifting line theory.…”

The Flow Visualization CFD Studies of the Fuselage and Rolled-up Vortex Effects of the Chengdu J-10-like Fighter Canard

“…It has been explained about the role of rolled-up vortex arises in 3-D wind turbine blades with Helicopter-Head-Like Propeller Blade Tips (Sutrisno et al, 2017) or blades with fin. In wind turbine blades, rolled-up vortex could perform laminarization effect on turbulent region which delay the stall.…”