A Study on the One-dimensional Design Equation of a Stepped Labyrinth Seal

Abstract

The performance of Labyrinth seal for sealing the secondary flow path of a gas turbine was predicted using Flomaster, a 1-dimensional code. First, the predictive ability of the straight-through seal module built into Flomaster was verified by comparing it with experimental data. The discharge coefficient was confirmed through the isentropic mass flow rate and the actual mass flow r ate found in Martin’s equation. The validity of the prediction using the one-dimensional code was verified through the straight-through seal, and the discharge coefficient according to the geometric variables was predicted using the stepped seal module built into the Flomaster. The performance of the seal predicted by the one-dimensional code was verified by comparing the results obtained with the three-dimensional CFD (computational fluid dynamics) data. Among the design variables of the stepped seal, the most important variable is the step height, but the effect is reduced above a certain height, so the design equation of the one-dimensional code could be used.