Impact dynamic analysis of C/C composite finger seal

Abstract

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.

Dynamic analysis of finger seal in the complex working state

“…A recursive procedure for calculating the friction between finger elements (or between the aft cover plate and the first finger element) is formed by equations (14) and (18).…”

“…Besides, the parameters affecting the dynamic performance of finger seal were discussed, including the rotor impact velocity and the impact coefficient of restitution. 13,14 It is clear that the effects of rotor tilt, assembly condition, temperature, and impact on the performance of finger seal were considered in previous studies, but only the single working condition was considered in the analyses (only one factor affecting the performance of finger seal was considered). Obviously, it is different in that the finger seal operates in the complex working state.…”

“…Besides, the parameters affecting the dynamic performance of finger seal were discussed, including the rotor impact velocity and the impact coefficient of restitution. 13,14…”

Wear analysis of finger locks with different design parameters for landing gear

“…5 The wear problem has been studied at home and abroad for a long time. 6 For example, in reference, 7,8 wear in complex working conditions will affect the dynamic performance of the mechanism. Wear is a phenomenon in contact.…”

Dynamic analysis and experimental verification of the carbon–carbon composite finger seal under complex working states

“…[11][12][13] Lu et al 14 established a finite element model of C/C composite finger seal, and analyzed its dynamic performance. Wang et al [15][16][17] carried out the dynamic performance analysis of the C/C composite finger seal under single work state by the equivalent dynamic model based distributed masses, and compared the results with those of Co-based alloy.…”