Three-Dimensional Inverse Method for Turbomachinery Blading Design

Abstract

An iterative procedure for 3D blade design is presented. The three-dimensional blade shape is modified using a physical algorithm, based on the transpiration model. The transpiration flux is computed by means of a modified Euler solver, in which the target pressure distribution is imposed along the blade surfaces. Only a small number of modifications is needed to obtain the final geometry. The method is based on a high resolution three-dimensional Euler solver. An upwind biased evaluation of the advective fluxes allows for a very low numerical entropy generation, and sharp shock capturing. The method is first validated, by redesigning an existing geometry, starting from a different one. It is further used to redesign a transonic compressor blade, to achieve, for the same mass flow and outlet flow angle, a shock free deceleration along the suction side. The last example concerns the design of a low aspect ratio turbine blade, with a positive compound lean to reduce the intensity of the passage vortices. The final blade is designed for an optimized pressure distribution, taking into account the forces resulting from the blade lean angle.

Advances in Aerodynamic Design of Gas Turbines Compressors

“…In the last two decades, three-dimensional inverse design methods have emerged and been applied successfully for a wide range of designs, involving both radial/mixed flow turbomachinery blades and wings (Zangeneh, 1991;Demeulenaere & Van Den Braembussche, 1996;Dulikravich & Baker, 1999). Quite a new approach to the 3D design of axial compressor bladings has been recently proposed by Tiow, 2002.…”

A numerical method for inverse design based on the inverse Euler equations

“…The advantage of these methods lies in their speed, since the most CPU intensive step in an optimization method, the computation of gradients, is avoided. The inverse methods are based either on a moving grid strategy [2,3] or on an intrinsic streamline aligned system of co-ordinates [4][5][6][7][8]. Methods implementing the second strategy are called single-pass methods.…”

Analytical and numerical investigation of the optimum pressure distribution along a low-pressure axial fan blade

“…The first would be the pressure distribution along the blade suction and pressure surfaces [3]. The preferred method, however, uses the blade pressure loading (the static pressure difference between the suction and pressure surfaces) and blade thickness distribution, resulting in the calculation of the mean camber line [4].…”