한국마린엔지니어링학회지 제37권 제2호, pp. 163∼169, 2013. 3 (ISSN 2234-8352 Online) / (ISSN 2234-7925 Print) Journal of the Korean Society of Marine Engineering http://dx.doi.org/10.5916/jkosme.2013.37.2.163 †Corresponding author: 534-729, 1666 Youngsan-ro, cheongye-myeon, Muan-gun, Jeonnam, Department of Mechanical Engineering, Mokpo National University, E-mail: ydchoi@mokpo.ac.kr, Tel: 061-450-2419 1 Graduate School, Mokpo National University, Mokpo, E-mail: holyrain@mokpo.ac.kr, Tel: 061-450-2419 2 Graduate School, Mokpo National University, Mokpo, E-mail: pms72006@yahoo.com, Tel: 061-450-2419 Influence of guide vane shape on the performance and internal flow of a cross flow wind turbine Sung-Woo Son 1 Patrick Mark Singh 2 Young-Do Choi (Received November 15, 2012； Revised February 15, 2013；Accepted February 15, 2013) Abstract: In order to make the vertical-axis cross flow wind turbine commercially feasible, a guide vane is adopted and the effect of the guide vane shape is examined in order to improve the wind turbine performance. CFD analysis on the performance and internal flow of the turbine is carried out for the wind turbine model. The result shows that when the guide nozzle is installed, almost over two times of power co- efficient are achieved in comparison with the case of no guide nozzle installation. The guide nozzle acts as a role of suppressing the flow resistance at the blade passage, which is found when the guide nozzle is installed. Moreover, in this study, two kinds of the guide vane with a straight type and a curved type are adopted and compared. The curved guide vane nozzle produces higher power coefficient in comparison with that of straight guide vane nozzle. Keywords: Vertical axis cross flow wind turbine, Guide nozzle, Guide vane, Performance, Internal flow 1. Introduction Recently, the environmental problems such as global warming, pollution problems and so on have been con- sidered as inevitable issue. Therefore, the necessity of the use of renewable energy as one of the clean and sustainable natural energy resources has become high[1]. As one of the renewable energy resources, the vertical axis wind turbines for the small scale urban usage are relatively less expensive as initial construction costs and maintenance costs are lower in comparison with those of the horizontal axis wind turbines[2]. Among the vertical axis wind turbines, a cross flow wind turbine has a high torque coefficient at a low tip speed ratio, good self starting characteristics, low noise, high stability and relatively very simple structure to manufacture[2]. However, the cross flow wind turbine has a demerit of relatively low maximum power coefficient as com- pared to that of other small wind turbines. Therefore, re- lated researches on the use of a guide nozzle in a cross flow turbine to improve the turbine performance has been conducted[3]-[6]. In the present study, in order to improve the perform- ance of a cross flow wind turbine more, guide nozzle with guide vane is suggested to enable uniform inlet flow conditions. The variation in performance and in- ternal flow due to the change in the shape of the guide vane are examined by CFD analysis. 2. Cross Flow Wind Turbine Models and Numerical Methods 2.1 Wind Turbine Models and Guide Vane Shapes In previous study[6], it has confirmed that cross flow wind turbine with guide nozzle shows considerably