Sıfır Emisyonlu Yenilenebilir Enerji Üreten Yelkenli Bir Tekne İçin Sualtı Türbin Tasarımı

Yıl 2016, Cilt: 7 Sayı: 3, 537 - 550, 01.12.2016

Serkan Ekinci Mustafa Alvar

Öz

Son yıllarda, rüzgar ve güneş enerjisi ile deniz ve gel-git akıntıları gibi yenilenebilir kaynaklardan elektrik
enerjisi üretimi üzerine yapılan teorik çalışmaların ve uygulamaların hızlı bir şekilde arttığı görülmektedir.
Bunlardan sualtı akıntı türbinleri, suyun değişik hareketlerinden yararlanarak enerji üreten sistemler
arasında olan ve düşük akım hızlarında dahi enerji üretebilme yeteneğine sahip, okyanus ve denizlerde
işletilen enerji üretme yöntemlerinden biridir.
Bu çalışmada, yelkenli bir tekne üzerinde sabit bulunacak ve yelken seyri sırasında tekne gövdesi etrafındaki
akıştan enerji elde edecek bir su altı akıntı türbininin, fonksiyon gereksinimleri doğrultusunda ön tasarımı ve
detay tasarımı gerçekleştirilmiştir. Tasarım aşamalarında, su altı türbin kanatlarının dizaynı, analizi ve
optimizasyonunda yaygın olarak kullanılan momentum kanat elemanı yöntemi (MBEM)’nden
yararlanılmıştır. Ön tasarım ve detay tasarım sonucunda ortaya çıkan yatay eksenli sualtı türbin sistemi,
bileşenleri ile birlikte gösterilmiştir. Bu sayede, üzerinde rüzgâr ve/veya güneş gibi yenilenebilir enerji
kaynaklarından enerji elde edebilen, depolayabilen ve gerektiğinde bu enerjiyi kullanabilen donanıma sahip
her yelkenli tekne için, güneş ve rüzgâr teknolojilerine göre daha fazla güç üretebilen, verimli, uzun ömürlü,
kullanımı kolay ve yenilikçi bir ürün ortaya konmuştur.

Anahtar Kelimeler

Yenilenebilir enerji, sualtı akıntı türbini, momentum kanat elemanı yöntemi

Marine current turbine design for zero emission renewable energy producing a sailing boat

Öz

In the recent years, rapid increase in theoretical
studies and applications on electrical power
generation from renewable sources, such as wind,
sun, marine or tidal currents, can be encountered in
the literature. Among these, marine current turbines,
produce energy by taking the advantage of
alternating motion of water, and have the ability to
produce energy even at low flow rates, and are
operated in oceans and seas as a renewable energy
source.
In this study, design of marine current turbine, to be
installed on a zero emission sail boat consept as a
prominent renewable energy source, is done. Firstly,
the design requirements of marine current turbine to
be installed on the sailboat are determined. So forth,
prerequisites for two marine current turbines, at
starboard and port, are turbine diameters to be less
than 700 mm, design speed to be 3.1 m / s (6 knots),
electrical power generation to be not less than 850
W, total appendage resistance to be not exceeding
5% of the ship resistance during the motor cruising
and also 25% of the ship resistance during the
sailing, in total, and weight of each turbine to be not
exceeding 35 kg. Considering the prerequisites
above, low Reynolds number turbine blade section
profile FX63-167, also used wind turbine blade
section with the highest CL/CD (lift coefficient/drag
coefficient) ratio, is chosen. Nevertheless,
considering manufacturing and productivity,
changes in the geometry of trailing edge of the
section is done. TSR, a substantial parameter for
marine turbines, and turbine diameter data from
available five marine current turbine in production,
ranging in diameter 3.1-6.3 m are taken into
account. For design, TSR and turbine diameter (D)
are considered to be 3.4 and 0.5 m, respectively.
TSR is an important parameter in turbine design.
Turbine, under the boat, aims to convert energy to
water flow that occurs on its body during the course
of sailing. In the meanwhile, it is causes an
additional resistance by acting as an appendage on
sail boat. The additional appendage resistance
reduces the speed of boat. It is inevitable. To
overcome, the most efficient system can be
developed by reducing it to the minimum. The
additional appendage resistance on the sail boat
occurs, since the two kinds of hydrodynamic forces
are generated on turbine. The first hydrodynamic
force is the viscous resistance component caused by
flow around turbine geometry. The other
hydrodynamic force is opposed thrust force,
rotational thrust acting in the opposite direction of
boat motion, occurring on turbine blades and trying
to stop the boat. The opposed thrust increases in
proportion with the increase in rotational speed of
the turbine. Therefore, choosing lower TSR values is
concluded in this study.
A computer code, based on momentum blade
element method, is used for blade geometry design
and optimization. At the end of optimization, turbine
speed (N), power coefficient (CP), tip speed ratio
(TSR), torque (T), thrust (F) and theoretical power
are calculated to be 460 rpm, 0.461, 3.882, 8.72 Nm,
827 N, 1383.5 W, respectively. The calculated final
geometric values for the turbine blades are given.
For the results obtained in pre-design calculations
to be close to practice and actual, turbine
mechanical design, including hub and pod parts, is
also carried out. The reason for the system to be
preferred as a folding system, is to minimize the
flow-induced resistances during the motor cruising.
A horizontal axis marine current turbine system with
all components is designed and presented. As a
result, an efficient, durable, easy to operate, and
innovative product is presented for sailing boat
which has capability to generate, accumulate and
consume alternative energy by using solar and/or
wind renewable energy sources.

Anahtar Kelimeler

Renewable energy, marine current turbine, momentum blade element method