Dynamic Simulation of Finger Seal-Rotor Interaction Using Variable Dynamic Coefficients

Proceedings of the Institution of Mechanical Engineers, Part C:

et al. 2016

The effect of a seal device on the performance of aeroengines is obvious. As well as the complicated operating state of aeroengines also has important influence on seal device performance. Finger seal is a new seal device, which has been extensively studied recently. However, so far there is little work about finger seal's dynamic performance considering work status. For this reason, finger seal's dynamic performance considering work status is proposed using equivalent dynamic model with distributed mass in this paper. The effects of the precession and nutation incline of rotor on the finger seal's performance are investigated. Meanwhile, density and preparation direction of fiber bundle have influence on its dynamic performance and that is studied under the rotor precession incline. Based on this, it is shown that the effect of rotor precession incline on the finger seal dynamic performance is obvious, thus it is necessary to consider the effect of the factor on finger seal dynamic performance. The present work is conducive to promote dynamic analysis technology of finger seal to engineering application, and also improve the theoretical research system and methodology of finger seal.

Section: Dynamic Performancementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of work status on leakage and contact pressure of C/C composite finger seal

Proceedings of the Institution of Mechanical Engineers, Part C:

et al. 2016

“…Braun et al 4 developed the one degree-of-freedom lumped mass equivalent dynamic model for the noncontact finger seal based on the assumption that the friction resistance was neglected, and they analyzed the parameters that affect the following performance of finger seal. Marie 5 established the two degrees-of-freedom lumped mass equivalent dynamic model as the friction between aft cover plate and low-pressure finger element was considered.…”

Section: Introductionmentioning

confidence: 99%

Dynamic analysis of finger seal in the complex working state

Zhao

Proceedings of the Institution of Mechanical Engineers, Part G:

et al. 2017

With the development of aero-engine industry technology, the operating conditions for finger seal become more horrible, including that high temperature, assembly type of finger seal, rotor tilt, and impact of rotor coexist. Unfortunately, the coupled effect on the dynamic performance of finger seal is not studied in previous works for the dynamic of finger seal. In this paper, the parameters of equivalent dynamic model for finger seal, including the equivalent structure stiffness of finger stick, the contact stiffness between finger stick and rotor, the friction heat between finger boot and rotor and the rotor displacement excitation, are corrected when the coupled effect of rotor tilt, assembly condition, temperature, and impact are considered. In addition, the distributed mass equivalent dynamic model is developed for considering the complex working conditions (including rotor tilt, assembly condition, temperature effect, and impact effect). Based on this model, the dynamic performance of finger seal in the complex working state is analyzed, and the influence of the complex working state on the dynamic performance is also studied. The results indicate that effect of the complex working state on the leakage performance and wear performance of finger seal is complex. The work in this paper demonstrates the necessity of considering the complex working conditions in the analysis of the dynamic performance of finger seal.

“…The results indicated that the working stability of the finger seal was improved through decreasing the change of the gas film gap. 9 Su and Chen 10 carried out the analysis of the hysteresis and contact performance of finger seal by equivalent dynamic model based on lumped mass. The design approach that the finger seal had low hysteresis and wear was discussed.…”

Section: Introductionmentioning

confidence: 99%

Impact dynamic analysis of C/C composite finger seal

Proceedings of the Institution of Mechanical Engineers, Part G:

et al. 2016

With the development of science and technology, the performance of an aero-engine has been given more rigorous requirements. Seal device is an important component part of an aero-engine, and the improvement in its performance may be an efficient way to further improve the performance of an aero-engine. Finger seal is a flexible seal and has higher performance price ratio, therefore it gets more attention and research recently. The phenomenon of noncontact state converting to contact state will occur in every working cycle of finger seal that inevitably lead to the finger seal bearing the impact effect of rotor. But so far, the influence of impact on the finger seal performance has not been discussed and researched. To overcome this shortcoming, the stress–strain curves of C/C composite under different impact velocities are obtained by the Gleeble3500 thermo-simulator system in the paper, and then the elastic modulus of C/C composite in three directions is calculated by experimental data. The effects of impact velocity and impact damping on the impact force are analyzed by means of the impact theory. The new structural stiffness of finger seal and the impact displacement excitation of the rotor are built through impact effect analysis. On this basis, the equivalent dynamic model of C/C composite finger seal with distributed mass is established to evaluate the impact effect. By the model, the difference of calculated results is analyzed under whether considering the impact effect or not. And the effect of impact velocity and coefficient of restitution on the dynamic performance of the finger seal is also analyzed under considering the impact effect, respectively. The above results show that the impact effect has significant influence on the leakage and wear of finger seal, therefore when the performance of the finger seal was analyzed, it is necessary to consider the impact effect.