A throughflow optimizing strategy for axial compressor transition duct in a marine gas turbine

To enhance the aerodynamic performance of transition duct between low pressure and high pressure axial compressor for a gas turbine, a through-flow optimization strategy considering practical operating conditions is proposed in this paper. The method integrates a high-order Bézier curve for modeling the end-wall flow path and a customized profile for the strut geometry, establishing a parameterized mathematical model to represent the duct’s through-flow structure. A composite objective function is formulated to simultaneously minimize total pressure loss and exit flow non-uniformity across multiple operating conditions. The optimization framework combines the Non-Linear Programming by Quadratic Lagrangian (NLPQL) algorithm with an Optimal Latin Hypercube Design (Opt-LHD) sampling strategy. Numerical simulations and experimental tests validate the approach using a redesigned transition duct. Results demonstrate significant improvements: at the design condition, the total pressure loss coefficient is reduced by 52.58%, and the outlet flow non-uniformity coefficient decreases by 34.72%. Flow field analysis reveals that optimized geometries mitigate adverse pressure gradients and suppress flow separation, particularly near strut-endwall junctions. Experimental results also confirms consistent performance enhancements across the full operating range, underscoring the effectiveness for gas turbines.