PSI - Issue 47

Bayu Anggara et al. / Procedia Structural Integrity 47 (2023) 675–684 Bayu Anggara, Dominicus Danardono DPT*, Eko Prasetya Budiana / Structural Integrity Procedia 00 (2019) 000 – 000 8

682

CP Clean CP Trapezoid 45 deg CP Rectangular 45 deg CP Triangular 45 deg

0,40

0,35

0,30

0,25

0,20

0,15

0,10 Power Coefficient

0,05

0,00

0,5

1,0

1,5

2,0

2,5

Tip Speed Ratio (TSR)

Fig. 7. Power coefficient with tip speed ratio 0.5-2.5

The graph in the Fig 7 shows the effect of adding HEV variations on the Darrieus H rotor blades with an installation angle of 45 degrees. The data shows that adding HEV increases Cp at TSR 1.0, 1.5, and 2.5. Even though at TSR 2 Cp, the resulting variation without HEV was higher than the triangular and trapezoidal variations, this variation eventually experienced a downward trend at TSR 2.5. It can be seen that adding HEV with trapezoidal and triangular geometries can delay flow separation, which in this case occurs at high TSR. 3.3. Turbulent Kinetic Energy Contour Analysis Figure 8 analyzes the turbulent kinetic energy in the turbine and the area around it TSR 1.5. Visualization is taken when the angle of attack is 0°. It can be seen that the variation with the addition of the HEV trapezoid experiences the highest kinetic energy, which is marked with a reddish color on the visualization. This is in line with the power coefficient achieved by the trapezoid variation at TSR 1.5, which is higher than the other variations. The installation of vortex generators on turbine blades was also suggested by Kolkman et al. (2018), consistently increasing the transfer of momentum from the outer area to near the boundary layer wall and inducing an increase in turbulent kinetic energy in the region near the wall. The HEV installation effect is also stated Dong and Meng (2004) that there is a relationship between the effect of the flow passing through the trapezoidal tab and the high turbulent kinetic energy generated.