Exploring Topology Optimization for High Pressure Turbine Blade Tips

Abstract

This work presents the aerodynamic topology optimisation of high pressure turbine rotor blade tips. Before carrying out the topology optimisation on the blade tip, some initial tip design studies were carried out. A winglet tip was optimised first and it was found that the optimum winglet design features a combination of small and largest overhangs possible that increase the aerodynamic efficiency by 1.40% compared to the datum design. Secondly, a radial basis function based parametrisation was set up to allow the creation of a single squealer rim on the datum blade's tip that could move position in the circumferential direction. The optimum case proved to increase efficiency by 0.46% compared to the flat datum tip of the same tip gap. After that, a combination of winglet and topology free squealer tips was investigated via topology optimisation. The winglet tip was created as in the winglet only optimisation cases and topology free squealer walls were parametrized and created using mapping of a radial basis function surface. It was shown that the radial basis function surface based parametrization creates a very flexible design space containing novel squealer topologies. Combining both winglet and novel squealer topology optimisation, better designs than the flat tip winglet can be achieved. However, because of the flexibility of the design space, gradient based methods were found to struggle to reach an optimum solution. This was resolved by optimising in the most promising design subspace.

Multidisciplinary Adjoint-based Optimizations in the MADELEINE Project: Overview and Main Results

“…The challenge here is to maximize the aerodynamic efficiency considering hard thermal and structural constraints. The Aero-Thermal-Cooling of the MT1 Turbine [31] (Figure 37) has been used in MADELEINE to show the benefits of using adjointbased MDO to design High-Pressure Turbine Blades. RR is working with USFD, UniCA, NTUA, ESI and OPT on this test case.…”

“…PADRAM provides a rich design space for the Turbine Tip, as shown in Figure 38 the Winglet and squealer are parameterized with spline points, however, in MADELEINE the use of the topology Optimization via the OPT Mimic tool is also explored [39]. Parametric free tip design has produced designs that are 0.3% better than a parametric-based optimized squealer tip [31]. A strong sealing effect has taken place due a counter rotating pair of vortices (Figure 41).…”