ISSN Online: 2377-424X
ISBN Print: 978-1-56700-474-8
ISBN Online: 978-1-56700-473-1
International Heat Transfer Conference 16
SHAPE OPTIMIZATION TO IMPROVE FILM-COOLING PERFORMANCE FOR LAIDBACK FAN-SHAPED FILM COOLING HOLE ON THE SUCTION SURFACE OF A TURBINE VANE
Abstrakt
In order to ensure the maximum film cooling effectiveness with minimum pressure loss, the three-dimensional CFD analysis and surrogate model approximation method were adopted to optimize
the shape of single row of laidback fan-shaped film holes on the suction surface of a turbine vane. Among the main geometric parameters, the dimensionless hole-to-hole pitch (P/d) and height-todiameter ratio (t/d) were fixed as 4.5 and 2.5 respectively. The inclination angle (α), lateral expansion angle (β) and forward expansion angle (γ) were selected as the design variables. Given the range of design variables as wide as possible, the geometric optimization of a laidback fan-shaped film hole was
carried out under a typical blowing ratio of M=1.5 by respectively selecting the area-averaged adiabatic film cooling effectiveness and discharge coefficient to evaluate the film cooling performance and pressure loss. Radial basis function neural network (RBFNN) was employed to construct the surrogate model, and a variant of non-dominated sorting genetic algorithm (NSGA-II) was coupled to perform a multi-objective optimization for obtaining the Pareto front of optimal solutions. Further, three typical optimal points selected from the Pareto front are evaluated by numerical simulation and the influence mechanism about the area-averaged adiabatic film cooling effectiveness and discharge coefficient is
illustrated according to the detailed flow field and heat transfer.