Labyrinth Diode Designed by Topology Optimization of Binary Structures using Laminar Flow and Real Gas Properties with Experimental Validation
Palavras-chave:
Topology Optimization, Labyrinth Diode, Laminar Flow, Experimental ValidationResumo
One of the most pressing issues that require attention is the reduction of CO2 emissions, and one approach to mitigate this problem is by enhancing the performance of diodes used for sealing and minimizing leakage in turbomachinery. This study focuses on the design of a labyrinth diode using the Topology Optimization of Binary Structures (TOBS) method, which incorporates laminar flow and real gas properties. The labyrinth diode design is obtained through TOBS, considering energy dissipation and vorticity magnitude as a multi-objective framework within a specified volume fraction. The optimization problem takes into account the dimensions of
the test bench and the properties of real CO2 gas in a two-dimensional axisymmetric model. The labyrinth diode design is optimized for laminar fluid flow governed by the Navier-Stokes equations, with the inclusion of the standard Darcy term to penalize solid domain infiltration. Computational Fluid Dynamics (CFD) is employed to numerically assess the diode’s performance and compare it with experimental measurements, evaluating its effectiveness in reducing leakage. The optimized topology is transformed into a solid model and fabricated using UV-photosensitive resin through 3D printing. The fabricated prototype is then tested on a test bench (TB) equippedwith a chamber capable of evaluating two seals with a middle entry, utilizing a 40 mm rotor. The TB can reach a maximum rotational speed of 10,000 rpm and generate a pressure drop of up to 5 bar. The leakage rate is measured in kg/s using instrumentation that adjusts the mass flow rate based on pressure/temperature analysis. The results indicate the need for further improvements to accommodate turbulent flow and higher Mach numbers in compressible flow during Topology Optimization. Nonetheless, the current findings offer promising insights into reducing leakage in turbomachinery seals.
