Leakage flow of pocket damper seal at high rotational speed

The leakage flow characteristics of the pocket damper seal(PDS) was numerical investigated with consideration of the rotor growth effect at the high rotational speed using finite element analysis/computational fluid dynamics(FEA/CFD).The leakage flow rate of the experimental pocket damper seal with 0.13mm clearance at three different pressure ratios and three different rotational speeds was conducted.The accuracy of the present numerical approach was demonstrated by comparison of the experimental data and numerical results without consideration of rotor growth.Six pressure ratios and six rotational speeds were utilized to analyze the leakage flow characteristics of the pocket damper seal.The influence of the higher pressure and higher rotational speed on the leakage flow characteristics of the pocket damper seal was analyzed.The obtained results show that for pressure ratio down to 0.26, the leakage flow rate of the pocket damper seal increases with the decreasing pressure ratio.The leakage flow rate of the pocket damper seal obtains the maximum value when the pressure ratio equals to 0.26.The Mach number of the leakage flow obtains 1 at the last fin clearance when the pressure ratio is 0.26.At the higher rotational speed, the leakage flow rate of the pocket damper seal decreases with the increasing rotational speed with and without consideration of the rotor growth effects.The rotor growth effect should be taken into account to predict the leakage flow rate of the pocket damper seal when Mach number exceeds 0.35.