Conjugate heat transfer characteristics of brush seal based on local thermal non-equilibrium porous medium approach

Computational model was developed for multi-physics coupling simulation of the flowing, heat transfer, frictional contact of the brush seal. A dual-energy equation was proposed to describe the conjugate heat transfer in the brush seal under local thermal non-equilibrium condition. Both the heat convection between the bristle and airflow and the anisotropy of heat conduction in the bristle pack were considered in the dual-energy equation. The temperature distributions of brush seal were numerically predicted using the developed computational model at various pressure ratios and rotational speeds. Results show that a local high temperature region is formed around the bristle-rotor contact area due to frictional heat effect of brush seal. The high temperature region of bristles is mainly located under fence height. The temperature distribution of airflow is similar to that of bristles due to strong heat convection between leakage airflow and bristles. The maximum temperature of bristles increases with the increasing pressure ratio. The average temperature under fence height region of bristles decreases with the increasing pressure ratio. The maximum temperature and average temperature under fence height region of bristles increase with the increasing rotational speed. The temperature rise effect of leakage airflow arising from frictional heat effect makes the leakage rate of brush seal decrease with the increasing rotational speed.