| As the main work unit of the core parts of turbomachinery such asturbine and compressor, blades realize the energy exchange process by theinteraction with fluid medium. The shape design of blades directlydetermines the work efficiency of blades, and of course affects theperformance of turbomachinery. Therefor it is necessary to have a researchon the aerodynamic optimization design of blade profile, to obtain a furtherperformance improvement of blades and a better utilization of energy.Combining Non-Uniform Rational B-Spline (NURBS), numericalsimulation and analysis of cascade flow field with a global optimizationmethod based on Kriging approximation model, an automatic aerodynamicoptimization method for turbine cascade is introduced in this investigation.Firstly, according to the principles of direct and inverse solution, theturbine blade profile described by discrete points is parameterized byNURBS curve and at last the control points are obtained. During theparameterization, the fitting precision can be improved by the optimizationof the weights.An automatic optimization method for turbine cascade aerodynamicdesign is set up by the combination of profile parametric modeling, solvingof series of geometric and mechanic properties, numerical simulation ofthe flow field and modern optimization algorithm. The data produced byevery part transfer automatically during the optimization. To accelerate theoptimization process, an adaptive sequential optimization algorithm basedon improved Kriging model is used to shorten the design period.Finally, shape optimization design of a turbine blade profile isperformed by the method. After the optimization of partial of the prototype profile, the total pressure loss coefficient is further reduced by1.49%atdesign condition. The results also show that better aerodynamicperformance is gained at different incidence, and the optimization methodused is reliable. This investigation has set up a good basis for the furtherstudy of multi-objective and multidisciplinary optimization of the turbineblade. |
