Investigation on the discharge and windage heating characteristics of staggered labyrinth seals under adiabatic and heat transfer models

Abstract

The applicability of numerical simulation is verified by experimental results obtained by Large-Scale Multifunction Sealing Heat Transfer Test Rig. Based on entropy production theory, the discharge and windage heating characteristics of smooth and honeycomb staggered labyrinth seals are numerically investigated. The results indicate that different wall temperatures have a significant impact on the discharge coefficient of staggered labyrinth seals, primarily due to variations in turbulent kinetic energy and dynamic viscosity. As pressure ratio increases, the discharge coefficient ratio of heat transfer to adiabatic model approaches a fixed value. Whether it is adiabatic wall or Tw = 300 K, the windage heating number decreases with pressure ratio until it tends to be flat. However, at RPM=8,000, this law at Tw = 500 K is inconsistent with that at other wall temperatures due to buoyancy force. In addition, more than 77 % of shaft work is converted into heat in smooth configuration, while more than 93 % in honeycomb configuration. It is worth mentioning that turbulent dissipation caused by turbulent fluctuation is the main factor of energy dissipation. The turbulent entropy production accounts for more than 64 % of total entropy production. This study provides theoretical and data support for subsequent multi-objective optimization.