From Conceptual 1D Design Towards Full 3D Optimization of a Highly Loaded Turbine Stage

Recent progress in additive manufacturing has enabled opportunities to explore novel stator rim geometries which can be implemented to improve cooling strategies in turbomachinery. This paper presents a simplified stationary geometry optimization strategy to produce enhanced stator-rotor cavity sealing and highlights main driving mechanisms. The stator and rotor rims were designed using a design strategy based on inspiration from the meandering of rivers. A minimum thickness of 2mm was maintained throughout the cavity to ensure a practical implementation. The computational domain comprised of the stator outlet, hub disk leakage cavity, and rotor platform was meshed using NUMECA Int. package, Hexpress. The numerical analysis required 3D Unsteady Reynolds Average Navier-Stokes to replicate vorticial structures using Ansys Fluent. The operating conditions were representative of engine-like conditions, exploring a wide range of massflow ratios from 1 to 3%. The optimization yielded designs that provide 30% reduction in rear platform temperature while minimizing coolant massflow. The applicability of the design was compared against 3D sector in both stationary and in rotation.

show abstract

“…6. The geometry is from Juangphanich et al [19]. The stator and rotor geometries are not used in the analysis.…”

Section: Computational Domain and Boundary Conditionsmentioning

confidence: 99%

Meander-Like Shape Optimization of the Stator-Rotor Platform Cavity

Juangphanich

Paniagua

2018

Volume 5C: Heat Transfer

Self Cite

View full text Add to dashboard Cite

show abstract

“…Turbomachinery aerodynamic design and optimization are vital towards guaranteeing the reduction of specific fuel consumption while maximizing the power output of future gas turbine engines [ 1 ]. The initial conceptual design of turbomachinery components often relies on expertise and design guidelines from previous engine programs.…”

Section: Introductionmentioning

confidence: 99%

Turbine Passage Design Methodology to Minimize Entropy Production—A Two-Step Optimization Strategy

Juangphanich

Maesschalck

Paniagua

2019

Entropy

Self Cite

View full text Add to dashboard Cite

Rapid aerodynamic design and optimization is essential for the development of future turbomachinery. The objective of this work is to demonstrate a methodology from 1D mean-line-design to a full 3D aerodynamic optimization of the turbine stage using a parameterization strategy that requires few parameters. The methodology is tested by designing a highly loaded and efficient turbine for the Purdue Experimental Turbine Aerothermal Laboratory. This manuscript describes the entire design process including the 2D/3D parameterization strategy in detail. The objective of the design is to maximize the entropy definition of efficiency while simultaneously maximizing the stage loading. Optimal design trends are highlighted for both the stator and rotor for several turbine characteristics in terms of pitch-to-chord ratio as well as the blades metal and stagger angles. Additionally, a correction term is proposed for the Horlock efficiency equation to maximize the accuracy based on the measured blade kinetic losses. Finally, the design and performance of optimal profiles along the Pareto front are summarized, featuring the highest aerodynamic performance and stage loading.Researchers have used Bezier curves [3] or a combination of splines and b-splines to design airfoil geometries. B-splines have been proven to be a successful tool in reducing turbomachinery loss when coupled to an optimizer. However, they have limitations. Shelton et al. [4] stated that it was difficult to induce large changes to the stagger, trailing edge wedge and leading edge angle using b-splines. They instead used b-splines as a tool to fine-tune the design of the blade. Ghaly and Mengistu [5] used Non-Uniform Rational B-Splines (NURBS) to optimize an existing turbine airfoil design in 2D-NURBS are similar to B-splines except their control points each have a weight. Their parameterization showed that NURBS required fewer points to parameterize a compressor airfoil [6], as opposed to a turbine blade [7] due to the increased curvature of the suction side. Shelton et al.[3] optimized a turbine blade under transonic conditions incorporating a stacking and sweep law. They similarly observed that it was difficult to make large changes to the stagger, wedge angle, and suction side surface angles in their parameterization using b-splines. Hasenjäger et al.[8] adopted b-splines to optimize a low aspect ratio stator blade in 3D and encountered difficulties as well, attempting to limit the number of control points needed to represent the blade surface using spline-like strategies.Bezier curves have been applied in a wide variety of turbomachinery applications because they offer designers the prospect of using less parameters while controlling the curvature by removing the need to parameterize the knot vector [9,10]. Goel et al. [11] used this type of curves to define 2D turbine airfoils using 10 and 8 parameters for the suction and pressure side respectively. Pierret and Van den Braembussche [12] employed a series of Bezier curves to model the suction and pressu...

show abstract

Study on one-dimensional performance prediction of multi-stage axial turbine based on the blade height

Xu,

Yuan,

et al. 2023

International Journal of Turbo &Amp; Jet-Engines

View full text Add to dashboard Cite

As turbine operating conditions change, the blade height and tip clearance undergo continuous alterations due to the combined effects of thermal stress, aerodynamic forces and centrifugal forces, subsequently influencing the turbine performance. To take this effect into account in turbine performance prediction, this study considers the influence of fluid-heat-structure coupling on blade height and tip clearance and establishes a one-dimensional comprehensive prediction method for multi-stage axial turbine performance considering blade height. When compared with experimental results from a four-stage axial turbine, by considering the fluid-thermal-solid coupling effects, the average relative error in total pressure ratio prediction is reduced from 3.76 % to 1.99 % and the average relative error in total temperature ratio prediction is reduced from 2.03 % to 1.26 %. Compared with the traditional flow prediction method, the prediction results of turbine characteristics considering blade height and tip clearance changes in this paper are closer to the experimental results.

show abstract

From Conceptual 1D Design Towards Full 3D Optimization of a Highly Loaded Turbine Stage

Cited by 4 publications

References 11 publications

Meander-Like Shape Optimization of the Stator-Rotor Platform Cavity

Meander-Like Shape Optimization of the Stator-Rotor Platform Cavity

Turbine Passage Design Methodology to Minimize Entropy Production—A Two-Step Optimization Strategy

Study on one-dimensional performance prediction of multi-stage axial turbine based on the blade height

Contact Info

Product

Resources

About