CFD Analysis of NREL Phase VI Horizontal Axis Wind Turbine (HAWT)

NREL Phase VI is well known test case in wind turbine field. This is two bladed horizontal axis wind turbine (HAWT) with diameter of 10.058 for simple tip. It rated power is 20 kW and rotational speed is 72 rpm. (NREL report ttps://www.nrel.gov/docs/fy02osti/29955.pdf). We have used configuration H for this course. Please go through NREL report and you will how many configurations are there.

In this course we have covered all steps necessary for any CFD analysis of Wind Turbine specially for horizontal axis wind turbine (HAWT) i.e.

• CAD modeling in Solidworks
• Domain creation in Spaceclaim
• Tetra-Prism meshing in ICEMCFD
• Problem setup and solution in Fluent
• Post processing in Fluent
• Results comparison and validation of CFD and experimental data.

Our first was to read the NREL report and try to find out important parameters. This is what I found from the report:

• Turbine diameter = 10.058
• Rotor speed = 72 rpm
• Inlet wind speed = 7 and 10 m/s for this course, otherwise speed varies from 5 m/s to 25 m/s for different cases.
• Number of blades = 2
• Global pitch angle (configuration H) = 3 Deg (provided in Spaceclaim

Then I found out that the turbine design is based on S809 airfoil:

S809 airfoil is used from 25% to 100% span as shown in following picture, second section is transition region from first airfoil to circle and last section is cylindrical support section as shown in following picture.

We have used following table to design blade in SOLIDWORKS

This is what we got after using S809 airfoil and above table in SOLIDWORKS:

We have imported SOLIDWORKS file into ANSYS Spaceclaim

After opening file in Spaceclaim we have given 3 deg pitch angle

Then I have created another blade using MOVE command with pattern option

After that hub was created and all three parts we combined to form one single solid body using combine command.

Using above model inner and outer domains were created in spaceclaim

Two domains i.e. inner and outer domain spaceclaim files were imported into spaceclaim and tetra prism meshing was generated. Inner domain contains around 12 million cells and inner domain contains 1 million cells.

These meshes were saved in Fluent form (.msh) and were imported into Fluent using read and Append command

Following settings were specified in Fluent for this problem

Here is convergence plot for residuals and torque

Post processing was done in Fluent as well

Domain size effect on results

Mesh study

Turbulence model study

You can subscribe to this course using following link: