An integrated procedure for the structural design of a composite rotor-hydrofoil of a water current turbine (WCT)

SERGIO ALEJANDRO OLLER ARAMAYO; LIZ G. NALLIM; SERGIO OLLER

APPLIED COMPOSITE MATERIALS

SPRINGER

Lugar: Berlin; Año: 2013 vol. 20 p. 1273 - 1288

0929-189X

This paper shows an integrated structural design optimization of a composite rotor-hydrofoil of a water current turbine by means the finite elements method (FEM), using a Serial/Parallel mixing theory (Rastellini et al. Comput. Struct. 86:879?896, 2008, Martinez et al., 2007, Martinez and Oller Arch. Comput. Methods. 16(4):357?397, 2009, Martinez et al. Compos. Part B Eng. 42(2011):134?144, 2010) coupled with a f luid-dy namic formulation and multi-objectiv e optimization algorithm (Gen and Cheng 1997, Lee et al. 2011, Lee et al. Compos. Struct. 99:181?192, 2013, Lee et al. Compos. Struct. 94(3):1087?1096, 2012). The composite hydrofoil of the turbine rotor has been design using a reinforced laminate composites, taking into account the optimization of the carbon fiber orientation to obtain the maximum strength and lower rotational-inertia. Also, these results have been compared with a steel hydrofoil remarking the dif f erent perf ormance on both structures. The mechanical and geometrical parameters inv olv ed in the design of this f iber-reinf orced composite material are the fiber orientation, number of lay ers, stacking sequence and laminate thickness. Water pressure in the rotor of the turbine is obtained f rom a coupled fluiddy namic simulation (CFD), whose detail can be f ound in the reference Oller et al. (2012). The main purpose of this paper is to achieve a very low inertia rotor minimizing the start-stop effect, because it is applied in axial water flow turbine currently in design by the authors, in which is important to take the maximum advantage of the kinetic energy. The FEM simulation codes are engineered by CIMNE (International Center for Numerical Method in Engineering, Barcelona, Spain), COMPack for the solids problem application, KRATOS for fluid dynamic application and RMOP for the structural optimization. To validate the procedure here presented, many turbine rotors made of composite materials are analyzed and three of them are compared with the steel one.