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W
1
WIDODO
1
, W.S., CHIN
2
, A.C., HAERYIP SIHOMBING
3
, and YUHAZRI
4
, M.Y.
1, 2, 3, 4
Faculty of Manufacturing Engineering Universiti Teknikal Malaysia Melaka
Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, MALAYSIA
1
wswidodoutem.edu.my
3
iphaery utem.edu.my
4
yuhazriutem.edu.my
1.0 I
NTRODUCTION
The developments of r enew able ener gy especially w ind ener gy become w idely since 1973 due to the oil cr isis issues. This view has been suppor ted by Peter et al., 2008 w ho states that the oil pr ice is for ecasted to be
r aised in the futur e and thus w ind ener gy is an alter native ener gy sour ces. The w ind tur bine is a device that utilizes w ind ener gy to gener ate mechanical or electr ical pow er . Accor ding to Manw ell et al., 2009, ther e ar e
tw o types of w ind tur bine: Hor izontal Axis Wind Tur bine HAWT and Ver tical Axis Wind Tur bine VAWT. HAWT ar e most commonly know n type of w ind tur bine and it oper ates par allel to the dir ection of the w ind
w her eas VAWT r otor is oper ated per pendicular to the direction of w ind. The tw o most common design pr inciple of VAWT is Savonius type and Dar r ieus type.
The paper focuses on the Savonius type r otor blades design and analysis. Savonius type r otor blade is a simple w ind tur bine that oper ates based on dr ag concept. Accor ding to Akw a et al., 2011 Savonius r otor can be
designed w ith tw o or thr ee blades, in single stage or multi-stages. The w or king pr inciple of Savonius r otor is r esembled to a cup anemometer . The low efficiency of VAWT limited its use in lar ge pow er pr oduction.
How ever , VAWT has sever al advantages over HAWT that make it w idely use in another sector such as w ater pumping system. The most appar ent advantage of VAWT is it can oper ate in all w ind dir ection and thus ar e built
w ithout using any yaw mechanism Halsey, 2011. Other advantages included low noise and simplicity.
In this pr oject, a VAWT is designed to pr oduce 5 kW pow er output. As the per for mance of VAWT is r elatively low , it becomes necessar y to explor e the effect of number of blades and sizing of the r otor blades in
the design stage. The Savonius w ind tur bine is a dr ag type VAWT w her e utilizes the drag for ce for its oper ation. D’Alessandr o et al., 2009 highlighted that the aer odynamic theor ies developed for lift type w ind tur bine
HAWT and Dar r ieus w ind tur bine cannot be applied for Savonius r otor . Accor ding to Islam et al., 2005 the flow patter n ar ound the Savonius r otor blade is char acter ized by flow phenomena that pr oduce pr essur e
differ ences betw een the concave and convex sur faces of the blades w hich w ill induce to aer odynamic for ce and tor que. Islam et al., 2005 fur ther explained that the featur e of flow phenomena including high tur bulence,
unsteadiness and flow separ ation. Figur e 1 show s the nor mal dr ag for ce, F
N
acts per pendicular on the blade sur face w her eas tangential dr ag for ce, F
T
acts along tangential dir ection on each blade. Both F
N
and F
T
equations have been stated by Islam et al., 2005 as follow :
F
N
=
∆
PS sin
∅
1 F
T
=
∆
PS cos
∅
2 Wher e the
△
P r epr esents the pr essur e differ ence betw een the concave and convex sur faces of the blade
and the S r epr esent the chor d length.
A BSTRA CT
This paper presents the design and analysis of the Savonius rotor blade to generate 5 kW power output. The relevant design parameters and theories were studied in this paper and used to
determine related design geometry and requirements of the Savonius rotor blade. The Savonius rotor was designed with the rotor diameter of 3.5 m and the rotor height of 7 m. The 3D model of Savonius
rotor blade was created by using SolidW orks software. Computational Fluid Dynamics CFD analysis and structural Finite Element Analysis FEA are presented in this paper. CFD analysis
was performed to obtain the pressure difference between concave and convex region of the blade while FEA was done to obtain the structural response of the blade due to the wind load applied in
term of stresses and its displacements. Key w ords:
Savonius, Rotor Blade, CFD, FEA.
DESIGN AND ANALYSIS OF 5 KW SAVONIUS ROTOR BLADE
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