Title: Numerical analysis of geometry and operating conditions in combined honeycomb and inclined labyrinth sealing elements

Authors: İbrahim Zengin; Beytullah Erdoğan

Addresses: Institute of Science, Department of Mechanical Engineering, Zonguldak Bülent Ecevit University, Zonguldak, 67100, Turkey ' Institute of Science, Department of Mechanical Engineering, Zonguldak Bülent Ecevit University, Zonguldak, 67100, Turkey

Abstract: Leakage flows occurring during operating conditions within the gas turbine engine system significantly affect the turbine efficiency. It is a significant issue to control and predict the leakage flow. This study covered the labyrinth seal with inclined tooth form and honeycomb seal used together. The combined seal provides more efficient leakage flow reduction than seal designs available in the literature. The study also focused on the five different parameters affecting the leakage flow, which are clearance size (Cr = 0.254-0.508-1.016 mm), honeycomb cell size (Lcell = 0.793-1.590-3.175 mm), pressure ratio (π = 1.5-2.0-2.5-3.0), rotor speed (Vr = 0-100-200-400 m/s), and tooth inclination angle (θ = 90°-70°-50°). These parameters were investigated comprehensively with ANSYS – Fluent, which uses the finite volume method. Results showed that in working conditions for low clearance, the use of honeycomb adversely affects the leakage flow while it has positive effects for wider Cr sizes. While the honeycomb geometry with a straight tooth reduces the leakage flow by about 11%, this ratio increases to 21.5% with the inclined tooth arrangement.

Keywords: sealing elements; honeycomb seal; inclined labyrinth tooth; sealing CFD.

DOI: 10.1504/PCFD.2023.128736

Progress in Computational Fluid Dynamics, An International Journal, 2023 Vol.23 No.1, pp.1 - 12

Received: 10 Mar 2021
Accepted: 22 Dec 2021
Published online: 02 Feb 2023 *