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Effect of flanged diffuser divergence angle on wind turbine: A numerical investigation
Tahir Abbas Jauhar1, Muhammad Imtiaz Hussain2, Tayybah Kiren3
1Department of Mechanical Engineering, University of Gujrat, Gujrat, Pakistan.
Plos One
|June 15, 2023
Summary
This study enhanced small wind turbine power using a flanged diffuser, achieving up to 1.68x wind speed improvement. Optimal designs minimized flow separation and maximized airflow for better energy capture.
Area of Science:
- Renewable Energy Engineering
- Aerodynamics
- Fluid Dynamics
Background:
- Small-scale horizontal axis wind turbines (HAWTs) performance is often limited by aerodynamic factors.
- Flanged diffusers can augment power output but are sensitive to design parameters like diffuser angle and back pressure.
Purpose of the Study:
- To numerically investigate the optimal placement of a wind turbine rotor within a flanged diffuser.
- To analyze the impact of varying diffuser angles and wind speeds on power augmentation and flow characteristics.
Main Methods:
- Computational Fluid Dynamics (CFD) was used to model and analyze shroud and flange configurations.
- Experimental validation was performed at 6 m/s and 8 m/s, comparing performance with and without the diffuser.
Main Results:
- A 4° divergence angle eliminated flow separation, maximizing flow rate and achieving a 1.68x wind speed improvement.
- The optimal flange height was determined to be 250 mm.
- Optimal wind turbine dimensionless location varied between 0.45 and 0.5 for 2° and 4° divergence angles, respectively.
Conclusions:
- The flanged diffuser design significantly enhances HAWT performance.
- Optimizing diffuser angle and turbine placement is crucial for maximizing power augmentation.
- This research offers valuable insights for improving small-scale wind energy systems.
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