416109

Hindawi Publishing Corporation Advanc es in Mechanic al Engineering V olume , Art icle ID , pages http://dx.doi.org/.// Research Article Numerical Analysis of Impulse Turbine for Isolated Pilot OWC System Zhen Li u, 1,2,3 Jiy uan Jin , 4 Ying Cui, 2 and Haiwen Fan 2 Shandon g Provincial Key Labora tory of Ocean Engineering, Ocean University of China, Qingdao -, China College of Engineering, Ocean University of China, Qingdao -, China Qingdao Municipal Key Laboratory of Ocean Renewable Energy , Ocean Univer sity of China, Qingdao -, China Research Institute Korea Institute of Ocean Science and echnology, Daejon -, Republic of Korea Correspondence should be addressed to Jiyuan Jin; [email protected] Received June ; Revised July ; Accepted July Academic Editor: Haitao Yu Copyright © Zhen Liu et al. Tis is an openaccess article distribute d under the Crea tive Commons At tribu tion Licen se, which permits unrestricted use, distribution, and reproductio n in any medium, provided the original work is properly cited. Oscillating water column (OWC) is the most widely used wave energy converting technology in the world. Te impulse turbine is recently bee n emp loyed as the rad ial tur bine in OWC ac ili tie s to conv ert bid irectional mec han ical air power into ele ctr ici ty power . D numerical model or the impulse turbine is established in this paper to investigate its operating perormance o the designed impulse turbine or the pilot OWC system which is under the construction on Jeju Island, Republic o Korea. Te proper mesh style, turbulence model , and numerical solu tions are employe d to stud y the veloc ity and air pre ssur e distri buti on especially aro und the rotor blade . Te oper atin g coeffic ient s obta ined rom the nume rical simul atio n are compare d with corr espo nding exper imen tal data, which demonstrates that the D numerical model proposed here can be applied to the research o impulse turbines or OWC system. Effects o tip clearances on ow eld distribution characteristics and operating perormances are also studied. 1. Introduction Oscillating water column (OWC) is the most widely used wave energy technology in the world. It is utilized to convert wa ve ene rgy into low pr ess ure pneumatic ene rgy in the orm o a bidirectional air ow. Capable o rotating in one- way under above ow conditions, Wells turbine or impulse tur bines linked to the ele ctri c genera tor in the air duct is generally used to convert the dynamic air pressure into mechanical energy. A number o efforts have been made to study the operating perormance o air turbines or OWC wave energy con- verters. Maeda et al. [ ] presented experimental research reports on the impulse turbine within xed guide vanes or the OWC wave energy converter. Iffects o guide vanes on Wells turbines in the reciprocating air ows are experimen- tally investigated in [ ], demonstrating better perormance than turbines without guide vanes. Te sel-starting characteristics and operating perormance o the Wells turbine in irregular waves are studied by experimental and numerical methods in []. Huang et al. [] proposed a simple method or dealing with effects o pressure drops induced by the Wells turbine on the op erating perormance o air chambers. Te tting ormula is used, which is derived rom laboratory research on the at plate as the Wells turbine ’ s pressure drop substitute. It was rst investigated or the tip clearance o impulse turbine by D numerical model, which has been reported by Takker and Dhanasekaran [] that the turbine with . tip clearance perormed almost similar to the case o without tip cle ara nce or ent ire ow coe ffici ent s. An accura te description o the steady three-dimensional ow eld in a high solidity Wells turbine was provided in [ ]. Te analysis has been perormed by numerically solving incompressible NS equations in a noninertial reerence rame rotating with the turbine. A design method combining two powerul design tools (Pugh concept analysis and D CAD environment) is used in [ ] in or derto creat e an imp rovedimpul se turbi ne usi ng a sys temat- ic method. An investigation on the perormance o a Wells turbine or wave energy conversion using the CFD method was reported by aha et al. [ ]. Te study utilized several nume rical models and NA CA blade pro les with vario us

Documents

416109