Numerical simulation of brush seal tests

Abstract

A numerical analysis of deformation of the brush seal wire package as part of dynamic rotor&stator system of gas turbine engines is describes. The estimated definition of the reaction force of the brush package is based on solving the contact problem of the interaction of bristles with each other, with the rotor and the rear plate of the seal case, taking into account the action of the distributed gas flow pressure. Comparison of the results obtained with the data of well-known estimated and experimental studies. According to the results of calculations, it was noted that the accounting of the spatial contact interaction of the elements of the brush seal significantly affects on reaction force value and, accordingly, on the brush package rigidity. In the presence of a gas pressure drop on the compaction, the results of calculations on a simplified half-analytical model based on the analysis of the deflection of one bristles according to the model of the flat bending of the console straight beam, and the spatial model differ in order. It is necessary to take into account this effect when calculating the wear of the brush seal and the forecast of its effectiveness with the course of operation. A characteristic feature of the dependence of the reaction of the brush package from the magnitude of the rotor displacement is the presence of hysteresis in the "load - unloading" cycle due to friction in the system. The impact of gas flow on the bristles significantly increases the scope of hysteresis loops and changes its shape. On the scale of the loop also strongly affects the coefficient of friction pair "schedules - rotor". The obtained dependences of the reaction of the brush package from the magnitude of the tension / displacement of the rotor (hysteresis loops) allow you to clarify the calculated mathematical model of the brush seal after testing on the stand.