Optimization of the Straight-Through Labyrinth Seal With a Smooth Land

Abstract

This paper presents the methodology and results of the optimization of a straight-through labyrinth seal with two inclined fins against smooth-land. The optimization was performed using commercial tools implemented in the ANSYS environment, such as goal-driven optimization. The response surfaces were created based on Latin hypercube samples found from computational fluid dynamics (CFD) calculations. The CFD solver, using a steady-state scheme with the k–ω shear stress transport (SST) turbulence model, was applied. A screening algorithm was used to find the best candidates on the response surfaces. The objective function adopted in the labyrinth seal optimization was the minimization of the discharge coefficient value. A wide range of parameters of the fins position and shape were taken into account, with physically justified degrees-of-freedom. The optimization results were supported by the results of an in-house experiment performed on a stationary, linear test rig. The test rig was fed by a high-capacity vacuum air blower with high-precision hot-wire anemometry mass flow evaluation. The reductions in the leakage significantly exceed the uncertainties of the CFD model and the test rig accuracy. The factors that had the most substantial impact on the leakage reduction were the location, inclination, and thickness of the fins. The experimental results were compared with the calculations and the optimization effects, highlighting some tendencies in the labyrinth seal flow behavior. Good agreement was obtained between the optimization results and the experimental data, proving that the presented methodology is sufficient for the labyrinth seal optimization.

Experimental and Numerical Analysis of the Gas Flow in the Axisymmetric Radial Clearance

“…It included the dissipations of kinetic energy, and the gas friction was described by the modified Blasius coefficient. Leakage in the labyrinth seal depends on various geometric parameters, such as the chamber shape [17,18], tooth thickness [19] and the angle of teeth inclination [20].…”

Novel Method of the Seal Aerodynamic Design to Reduce Leakage by Matching the Seal Geometry to Flow Conditions

“…The leakage minimization and decreasing total increase of enthalpy resulting from the friction were taken as the optimization criterion. The paper [28] presents the method for optimizing the straight through sealing with the use of CFD by changing the teeth inclination angle and spacing. The paper [29] presents an optimization model taking into account such design variables as the seal clearance, teeth width, teeth height, pitch, and teeth backward and forward expansion angle.…”

Universal Method for Determination of Leakage in Labyrinth Seal

“…Leak-tightness of the seal depends on such features of the seal geometry as pitch, length and height of the chamber (Zhang et al 2014, Wang et al 2007, Joachimiak and Krzyślak 2019, Szymanski et al 2018, Lampart, 2009. Of significant impact on the seal leak-tightness is its wear, Joachimiak and Krzyślak (2017).…”