摘要：This study presented a hybrid model method based on proper orthogonal decomposition(POD) for flow field reconstructions and aerodynamic design optimization. The POD basis modes have better description performance in a system space compared to the widely used semi-empirical basis functions because they are obtained through singular value decomposition of the *** of the widely used linear regression, nonlinear regression methods are used in the function response of the coefficients of POD basis modes. Moreover, an adaptive Latin hypercube design method with improved space filling and correlation based on a multi-objective optimization approach was employed to supply the necessary samples. Prior to design optimization, the response performance of POD-based hybrid models was first investigated and validated through flow reconstructions of both single-and multiple blade rows. Then, an inverse design was performed to approach a given spanwise flow turning distribution at the outlet of a turbine blade by changing the spanwise stagger angle, based on the hybrid model method. Finally, the span wise blade sweep of a transonic compressor rotor and the spanwise stagger angle of the stator blade of a single low-speed compressor stage were modified to reduce the flow losses with the constraints of mass flow rate, total pressure ratio, and outlet flow *** results are presented in detail, demonstrating the good response performance of POD-based hybrid models on missing data reconstructions and the effectiveness of POD-based hybrid model method in aerodynamic design optimization.

摘要：The shear-stress transport(SST)turbulence model is incorporated into Navier-Stokes equations to simulate a turbomachinery flowfield.A staggered finite volume method is used to make the mean flow equations and turbulence model equations strongly coupled and enhance the stability of the numerical *** implicit treatment of the source terms is applied to the SST model.A steady state solution is obtained using five-stage Runge-Kutta time-stepping scheme with local time stepping and residual smoothing to accelerate convergence. The wall distance d,a key parameter in the SST model,is solved by a partial differential *** validations of the code are conducted on rotor 37,wp11 at design and off-design conditions by comparison with measurements and the Spalart-Allmaras(SA)turbulence *** flow within the tip is calculated with a multi-block grid.

摘要：An optimum design of the turbine would need a clear understanding of the influence of blade geometry on a Wells turbine performance. Practically, it is difficult to suggest the optimum geometry for the Wells turbine due to the complex interrelation among important parameters, the solidity, hub-to-tip ratio, aspect ratio, blade sweep of rotor, and so on. In the present study, the effect of blade geometry with the hub-to-tip and aspect ratios of rotor on the turbine performance was investigated with a numerical technique. As a result, the optimum blade geometry is as follows: the hub-to-tip ratio is about 0.7, and the aspect ratio about 0.5 under other constant important parameters, NACA0020 blade with blade sweep ratio of 0.35, and solidity of about 0.67. Furthermore, the detailed flow patterns for blade geometry were also shown and discussed in this paper.

摘要：Two concepts of the guide vanes channels design for a low head hydraulic turbine were investigated using 2D and 3D models. Model 2D was used to generate the geometry of profiles which form a blade channel. After that by means of 3D commercial code （ANSYS/Fluent v. 15）, the designed cascades were examined. The characteristic parameters of compared guide vanes have been presented. The problem of low head hydraulic turbine design is important from the technical point of view for usually not typical environmental circumstances, in which the hydropower plants are planned.