Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Investigating the Power-Performance Prediction on an H- and Helical-type Tidal Current Turbine Using CFD Method

CFD에 의한 H 및 Helical 타입 조류발전용 터빈의 출력성능예측에 관한 연구

  • Kim, Bum Suk (Faculty of Wind Energy Engineering, Graduate School, Jeju Nat'l Univ.)
  • 김범석 (제주대학교 대학원 풍력공학부)
  • Received : 2014.12.04
  • Accepted : 2015.06.08
  • Published : 2015.08.01
Download PDF
⟨ Previous Next ⟩

Abstract

In this study, we conduct power performance and load analyses of two different types of vertical-axis tidal-current turbines using the computational fluid dynamics (CFD) method. To analyze the power output and loads, we perform transient CFD simulations considering the cavitation model using ANSYS CFX. The averaged power output of an H-type rotor was 7.47 kW and 67.6 kW in normal and extreme operating conditions, respectively, which did not satisfy the initial design conditions. However, in the case of the helical-type rotor, the power output under normal and extreme conditions were close to the expected values. The cavitation, which may cause instantaneous power fluctuation, occurred repeatedly at the suction side of the rotors. In order to guarantee a more stable power supply and to prevent fatigue failure, we require a design that minimizes cavitation.

본 연구에서는 CFD 해석기법을 이용하여 서로 다른 두 가지 형식의 수직축 조류발전용 터빈에 대한 출력성능 및 하중 해석을 수행하였다. ANSYS CFX를 이용하여 시간변화에 따른 해석을 수행하였으며, H 타입 로터의 정상 및 극치운전조건에서 각각 7.47kW와 67.6kW의 출력이 나타났다. 이는 초기 설계조건에 적합하지 않은 것으로 확인되었으며, helical 타입 로터의 정상 및 극치운전조건에서는 출력성능이 거의 설계 운전점에 가까운 특성을 나타내었다. 블레이드 주변에 발생하는 캐비테이션은 두 종류의 로터 블레이드 모두에서 반복적으로 발생되었으며, 조류 터빈의 순간 출력변화에 많은 영향을 미칠 수 있다. 따라서 안정적인 출력품질의 확보 및 피로파손 방지를 위해서는 캐비테이션 현상의 발생을 최소화 할 수 있는 설계가 필요하다.

Keywords

References

  1. Nicholls-Lee, R. F., Turnock, S. R. and Boyd S. W., 2008, "Simulation based Optimisation of Marine Current Turbine Blades," 7th International Conference on Computer and IT Applications in the Maritime Industries, pp. 314-328.
  2. Bahaj, A.S., Molland, A.F., Chaplin, J.R. and Batten, W.M.J., 2007, "Power and Thrust Measurements of Current Turbines Under Various Hydro Dynamic Flow Conditions in a Cavitation Tunnel and a Towing Tank," Journal of Renewable Energy, Vol. 32 No. 3, pp. 407-426. https://doi.org/10.1016/j.renene.2006.01.012
  3. Batten, W.M.J., Bahaj, A.S., Molland, A.F. and Chaplin, J.R., 2008, "The Prediction of the Hydrodynamic Performance of Marine Current Turbines," Journal of Renewable Energy, Vol. 33, pp. 1085-1096. https://doi.org/10.1016/j.renene.2007.05.043
  4. Francis, M. and Hamilton, M., 2007, "SRTT Floating Tidal Turbine Production Design Study with Independent Verification," AEA Energy & Environment, 07/1463.
  5. Harrison, M.E., Batten, W.M.J., Myers, L.E. and Bahaj, A.S., 2009, "A Comparison between CFD Simulation and Experiments for Predicting the far Wake of Horizontal Axis Tidal Turbines," 8th European Wave and Tidal Energy Conference, Sweden.
  6. Kim, B.S., Kim, W.J., Bae, S.Y., Park, J.H and Kim, M.E., 2011, "Aerodynamic Design and Performance Analysis of Multi-mw Class Wind Turbine Blade," Journal of Mechanical Science and Technology, Vol. 25, No, 8, pp. 1-8.
  7. Menter, F.R., Kuntz, M. and Langtry, R., 2003, "Ten Years of Industrial Experience with the SST Turbulence Model," Turbulence, Heat and Mass Transfer 4, Begell House, Inc., pp. 625-632.
  8. Kim, B.S., Bae, S.Y., Kim. W.J. and Lee, S.L. and Kim. M.K., 2012, "A Study on the Design Assessment of a 50 kW Ocean Current Turbine Using Fluid Structure Interaction Analysis," IOP Conference Series: Earth and Environmental Science, Vol. 15, p. 042037.