Topology optimization method for turbulent flow with application to helical-type labyrinth seals

• Grant number: 22/07937-7
• Support Opportunities: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): August 01, 2022
• Effective date (End): July 31, 2023
• Field of knowledge: Engineering - Mechanical Engineering - Mechanical Engineering Design
• Acordo de Cooperação: BG E&P Brasil (Shell Group)
• Principal Investigator: Julio Romano Meneghini
• Grantee: Diego Hayashi Alonso
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Host Company: Universidade de São Paulo (USP). Escola Politécnica (EP)
• Associated research grant: 20/15230-5 - Research Centre for Greenhouse Gas Innovation - RCG2I, AP.PCPE

Abstract

This work is inserted in the project "Design of smart labyrinth seals to reduce GHG emissions in pneumatic machines (compressors and turbines)", which is being developed in the Research Centre for Greenhouse Gas Innovation (RCGI), under FAPESP grant 2014/50279-4. One important source of GHG (greenhouse gases) emission is turbomachine leakage, which is directly related to sealing. In particular, labyrinth seals are noncontact seals that are widely used in the industry, mostly featuring a passive operation. However, the helical-type labyrinth seal has the potential to pump the leakage flow back to the inside of the turbomachine, meaning that it has the potential to achieve zero leakage, which is not possible without such active motion. Most works on labyrinth seals are centered around experimental analysis and simulations, but there are also works on parametric and shape optimizations. More recently, the topology optimization method, which is the most flexible and generic optimization approach, started being investigated for labyrinth seals. Moreover, the use of topology optimization in the design of helical-type labyrinth seals may improve its reverse pumping capability. The proposed research in fluid topology optimization encompasses some current challenges, such as higher rotational motions and turbulent flow. The numerical implementation will be performed in open source softwares, namely FEniCS/dolfin-adjoint for the adjoint model and optimization framework, OpenFOAM® for the simulation, and "FEniCS TopOpt Foam" for coupling both softwares. (AU)