Numerical Optimization for Advanced Turbomachinery Design

Abstract

The multilevel-multidisciplinary-multipoint optimization system developed at the von Kármán Institute and its applications to turbomachinery design is presented. To speed up the convergence to the optimum geometry, the method combines an Artificial Neural Network, a Design Of Experiment technique and a Genetic Algorithm. The different components are described, the main requirements are outlined and the basic method is illustrated by the design of an axial turbine blade.A procedure for multipoint optimization, aiming for optimal performance at more than one operating point, is outlined and applied to the optimization of a low solidity diffuser.The extension to a multidisciplinary optimization, by combining a Navier-Stokes solver with a Finite Element Analysis, allows an efficient search for a compromise between the sometimes conflicting demands of high efficiency and respect of mechanical constraints. It is shown that a significant reduction of the stresses is possible with only a small penalty on the performance and that this approach may lead to geometries that would normally be excluded when using less sophisticated methods.

Effect of blade installation angle on power efficiency of resistance type VAWT by CFD study

“…The unsteady Reynolds-averaged Navier-Stokes equations are solved using the pressure-implicit with splitting of operators (PISO) pressure-velocity coupling scheme that is a part of the SIMPLE family of algorithms [26]. The model of turbulence is k-x shear-stress transport (SST) which was developed by Menter to effectively blend the robust and accurate formulation of the k-x model in the near wall region with the free-stream independence of the k-e model in the far field and discretization scheme for momentum equation is the quadratic upwind interpolation of convective kinematics (QUICK) which may provide better accuracy than the second-order scheme for rotating or swirling flows and is applicable to quadrilateral or hexahedral meshes.…”

“…Figure 3 shows the details of the blade surface. The rotating zone and the stationary zone are separated by an interface which is two interfaces superposed [24][25][26].…”

Variable-Fidelity Aerodynamic Shape Optimization

“…The Euler equations are exact, while FPE is an approximation (weak shocks) to those equations, and TSDE is a further approximation (thin airfoils at small angle of attack). These approaches can be applied effectively for high-speed design, such as the cruise design of transport aircraft wings [13,14] and the design of turbomachinery blades [2].…”

Inverse airfoil design using variable-resolution models and shape-preserving response prediction

“…Aerodynamic shape optimization (ASO) involves the design of aerodynamic components such as aircraft wings and turbine blades [6,24]. The state-of-the-art ASO design methods employ high-fidelity computational fluid dynamics (CFD) simulations as a part of efficient numerical optimization algorithms [2,10,27,28].…”