A simple theory and performance prediction for a shrouded wind turbine with a brimmed diffuser

Koichi Watanabe, Yuji Ohya

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)


We developed a new wind turbine system that consists of a diffuser shroud with a broad-ring brim at the exit periphery and a wind turbine inside it. The shrouded wind turbine with a brimmed diffuser, which we called a “wind lens turbine” (WLT), has demonstrated power augmentation by a factor of about 2–5 compared with a bare wind turbine for a given turbine diameter and wind speed. The increase in power output depends on the diffuser shape and length and the brim height. However, a simple theory presented in this paper argues that only two performance coefficients are needed to predict the performance of WLT. The coefficients are the back pressure coefficient of the brim and the pressure recovery coefficient of the diffuser. We theoretically showed that the back pressure coefficient was particularly important for the performance of WLT. Finally, the simple theory was evaluated with experimental results. The results showed good agreement with each other.

Original languageEnglish
Article number3661
Issue number12
Publication statusPublished - Jun 2 2021

All Science Journal Classification (ASJC) codes

  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Energy Engineering and Power Technology
  • Energy (miscellaneous)
  • Control and Optimization
  • Electrical and Electronic Engineering


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