Academia.eduAcademia.edu

Figure from:Wind energy investigation of straight-bladed vertical axis wind turbine using computational analysis

See full PDFdownloadDownload figure
When the velocity is considered, again, similar behavior is shown initially by both blade profiles. At the impact point, the value of velocity is reduced, as seen from the figure, whereas near side edges, velocities of rates increase, resulting in lift force.

Figure 9 When the velocity is considered, again, similar behavior is shown initially by both blade profiles. At the impact point, the value of velocity is reduced, as seen from the figure, whereas near side edges, velocities of rates increase, resulting in lift force.

Related Figures (16)

Figure 1. NACA0012 profile
Figure 1. NACA0012 profile
1.3.3. Selection of NACA0012, NACA2415 based on the following
1.3.3. Selection of NACA0012, NACA2415 based on the following
The methodology process starts with analyzing and studying different research work. Additional research articles have been reviewed on various topics related to blade design aerodynamics and parameters. It has been decided to investigate blade profiles with ANSYS-Fluent software platform, which is widely used in the aerodynamic and automobile industries. The flow chart given below shows the primary analysis sequence used here.
The methodology process starts with analyzing and studying different research work. Additional research articles have been reviewed on various topics related to blade design aerodynamics and parameters. It has been decided to investigate blade profiles with ANSYS-Fluent software platform, which is widely used in the aerodynamic and automobile industries. The flow chart given below shows the primary analysis sequence used here.
Figure 5. Meshed geometry near airfoil edges (Zoom view) For mesh distribution, several features of meshing in ANSYS-Fluent is used. For body sizing, the element size as 0.5 mm is provided, which is enough good compare to 180 mm. then edge sizing is given on the inlet and outlet wall. The number of divisions selected was 200, which was enough for edge sizing. Meshing is done according to these parameters by selecting appropriate edges and reference surfaces.
Figure 5. Meshed geometry near airfoil edges (Zoom view) For mesh distribution, several features of meshing in ANSYS-Fluent is used. For body sizing, the element size as 0.5 mm is provided, which is enough good compare to 180 mm. then edge sizing is given on the inlet and outlet wall. The number of divisions selected was 200, which was enough for edge sizing. Meshing is done according to these parameters by selecting appropriate edges and reference surfaces.
Figure 4. Geometry of NACA0012 at a=0° surfaces, the Boolean function of ANSYS-Fluent from the concept is used. It has been prepared in Workbench.
Figure 4. Geometry of NACA0012 at a=0° surfaces, the Boolean function of ANSYS-Fluent from the concept is used. It has been prepared in Workbench.
Figure 6 presented the pressure variation of NACA0012 aerofoil. Figure 6. Pressure variation of NACA0012
Figure 6 presented the pressure variation of NACA0012 aerofoil. Figure 6. Pressure variation of NACA0012
Figure 8. Pressure variation of NACA2415 From the pressure variation on NACA2415 profile, it is invistigated that both the blade profiles show similar kinds of behaviors. The higher pressure values at the leading edge that is the impact point, red color shows a higher value of pressure, where blue color is indicating the least value of pressure. Near the side edges, the pressure is reduced for both the profiles, and this variation in pressure helps in lift force, and those are presented in figures 6 to 9.
Figure 8. Pressure variation of NACA2415 From the pressure variation on NACA2415 profile, it is invistigated that both the blade profiles show similar kinds of behaviors. The higher pressure values at the leading edge that is the impact point, red color shows a higher value of pressure, where blue color is indicating the least value of pressure. Near the side edges, the pressure is reduced for both the profiles, and this variation in pressure helps in lift force, and those are presented in figures 6 to 9.
Pressure and velocity variations are appropriately compared here in figures 10 and 11. The analysis was with two different Reynolds numbers cases, which are 50000 and 100000. The following results are observed: At 50000 Reynolds number, lift and drag coefficients are studied. For a=0°, the lift coefficient is zero for the symmetric blade that is NACA0012 whereas for asymmetric that is NACA2415 is 0.0354 turning higher lift to drag coefficient. Similarly, for 100000 Reynolds number, analysis has been done. The lift coefficient is 0 for NACA0012, and the value of the lift coefficient is 0.01918 for asymmetric profile design, which is presented in figures 12 and 13.
Pressure and velocity variations are appropriately compared here in figures 10 and 11. The analysis was with two different Reynolds numbers cases, which are 50000 and 100000. The following results are observed: At 50000 Reynolds number, lift and drag coefficients are studied. For a=0°, the lift coefficient is zero for the symmetric blade that is NACA0012 whereas for asymmetric that is NACA2415 is 0.0354 turning higher lift to drag coefficient. Similarly, for 100000 Reynolds number, analysis has been done. The lift coefficient is 0 for NACA0012, and the value of the lift coefficient is 0.01918 for asymmetric profile design, which is presented in figures 12 and 13.
Figure 12. Coefficient of lift vs drag
Figure 12. Coefficient of lift vs drag
For the second part, the pitch angle is diverse in the range of -12.5 degrees to 10 degrees. The coefficients of lift and drag are found out at different angles. Reynolds number is considered as 100000, and different pitch angles are considered while analyzing.
For the second part, the pitch angle is diverse in the range of -12.5 degrees to 10 degrees. The coefficients of lift and drag are found out at different angles. Reynolds number is considered as 100000, and different pitch angles are considered while analyzing.
For the range of pitch angles and Reynolds number 100000, lift, drag, and lift coefficient is studied. After analysis, the lift coefficient value to drag is highest at a = - 5° value of the lift coefficient as 0.6141 and for drag as 0.01674, which is presented in figure 15.
For the range of pitch angles and Reynolds number 100000, lift, drag, and lift coefficient is studied. After analysis, the lift coefficient value to drag is highest at a = - 5° value of the lift coefficient as 0.6141 and for drag as 0.01674, which is presented in figure 15.