Contribution in Optimization of Honeycomb Abradable Seals Structure

Abstract

The abradable coatings had significantly enhanced turbomachinery performance by acting as a sacrificial seal between rotating blades and stationary casing. Further improvement in seal design to meet the higher energy demand and increase the service time has been the key challenges to solve in the gas turbine industry. Honeycomb seals have become the industry standard clearance seal technique due to their unique design and high structural strength with minimum weight. The present study proposes a concept to form a thermal shock resistance structure to achieve higher temperature capability and improve the reliability of abradable seal structures. A cavity layer of honeycomb seal structure made of SS 321 alloy was coated with advanced high-temperature ZrO2+7.5%Y2O3+4% polyester seal material using TriplexPro-210 plasma spray system. The integrity of a seal structure was assessed by a cross-sectional analysis and evaluation of the coating microstructure. Additionally; the microhardness test was performed to estimate coating fracture toughness; and Object-Oriented Finite Element analysis was used to assess its thermo-mechanical performance. The concept proposed in this study should be further validated to develop the most capable innovative technology for advanced gas turbine abradable seal structures.

Microstructure Image-Based Finite Element Methodology to Design Abradable Coatings for Aero Engines

“…In Bérenger Berthoul [26,27], a new framework was created for simulating coating wear in turbomachinery. Coating abrasion phenomenology research served as the foundation for the model.. Pathak, P. [28] proposed the development of a thermal shock resistance structure to improve the temperature capacity and reliability of abrasion-resistant seal structures. The coating's fracture toughness was measured using microhardness testing, and its thermomechanical performance was evaluated using object-oriented finite element analysis.…”