Automatic Three-Dimensional Optimisation of a Modern Tandem Compressor Vane

Abstract

In order to increase the performance of a modern gas turbine, compressors are required to provide higher pressure ratio and avoid incurring higher losses. The tandem aerofoil has the potential to achieve a higher blade loading in combination with lower losses compared to single vanes. The main reason for this is due to the fact that a new boundary layer is generated on the second blade surface and the turning can be achieved with smaller separation occurring. The lift split between the two vanes with respect to the overall turning is an important design choice. In this paper an automated three-dimensional optimisation of a highly loaded compressor stator is presented. For optimisation a novel methodology based on the Multipoint Approximation Method (MAM) is used. MAM makes use of an automatic design of experiments, response surface modelling and a trust region to represent the design space. The CFD solutions are obtained with the high-fidelity 3D Navier-Stokes solver HYDRA. In order to increase the stage performance the 3D shape of the tandem vane is modified changing both the front and rear aerofoils. Moreover the relative location of the two aerofoils is controlled modifying the axial and tangential relative positions. It is shown that the novel optimisation methodology is able to cope with a large number of design parameters and produce designs which performs better than its single vane counterpart in terms of efficiency and numerical stall margin. One of the key challenges in producing an automatic optimisation process has been the automatic generation of high-fidelity computational meshes. The multi block-structured, high-fidelity meshing tool PADRAM is enhanced to cope with the tandem blade topologies. The wakes of each aerofoil is properly resolved and the interaction and the mixing of the front aerofoil wake and the second tandem vane are adequately resolved.

A Novel Surface Parameterization Method for Optimizing Radial Impeller Design in Fuel Cell System

“…Omidi et al [21] used a hybrid method, comprising a genetic algorithm and a simulation package to realize the global optimization, simulate the function of a radial com impeller pressor, and evaluate the effects of losses in the impeller. In terms of the parametric optimization, blade parameterization methods are mainly divided into two categories: one is to fix the shape of each section and only change the position of the stacking line; the other is to reshape the geometry of each section, i.e., deform the pressure and suction surfaces, or directly change the mid-arc and thickness distribution [22,23]. Hehn et al [24] used three independently designed camber curves instead of ruled surfaces to optimize the blade geometry and aerodynamic analysis, which required 156 optimization variables.…”

A Novel Surface Parametric Method and Its Application to Aerodynamic Design Optimization of Axial Compressors

“…Thus, it is rarely used in an actual optimization project. The second category is to take the control parameters of free curves that fit the central arc of the 2D cascade geometry [7][8][9][10] or the profile of the suction and pressure side as optimization variables [11][12][13][14]. These control parameters can control the geometric changes in the 3D blades during the optimization process.…”

Analysis of Flow Characteristic of Transonic Tandem Rotor Airfoil and Its Optimization

“…The numerical optimization method can help designers find the optimal solution, and even carry out in-depth analysis to further understand the flow mechanism. Schlaps et al [15] optimized the 3D tandem stator relative position with the multiobjective algorithm, and the optimal relative position principle was summarized. Ju et al [16] optimized a 2D tandem blade with the multiobjective genetic algorithm and artificial neural network method.…”