Abstract: The incorporation of computational fluid dynamics in the design of modern hydraulic turbines appears to be necessary in order to improve their efficiency and cost-effectiveness beyond the traditional design practices. A numerical optimization methodology is developed and applied in the present work to a Turgo water turbine. The fluid is simulated by a Lagrangian mesh-free approach that can provide detailed information on the energy transfer and enhance the understanding of the complex, unsteady flow field, at very small computing cost. The runner blades are initially shaped according to hydrodynamics theory, and parameterized using Bezier polynomials and interpolation techniques. The use of a limited number of free design variables allows for various modifications of the standard blade shape, while stochastic optimization using evolutionary algorithms is implemented to find the best blade that maximizes the attainable hydraulic efficiency of the runner. The obtained optimal runner design achieves considerably higher efficiency than the standard one, and its numerically predicted performance is comparable to a real Turgo turbine, verifying the reliability and the prospects of the new methodology.
Abstract: This work is an attempt to use the standard Smoothed
Particle Hydrodynamics methodology for the simulation of the
complex unsteady, free-surface flow in a rotating Turgo impulse
water turbine. A comparison of two different geometries was
conducted. The SPH method due to its mesh-less nature is capable of
capturing the flow features appearing in the turbine, without
diffusion at the water/air interface. Furthermore results are compared
with a commercial CFD package (Fluent®) and the SPH algorithm
proves to be capable of providing similar results, in much less time
than the mesh based CFD program. A parametric study was also
performed regarding the turbine inlet angle.