Investigation of the Effect of Wave Reflection in the Forced Response Study of a Compressor

Main Authors: Mao, Zhiping, Pan, Tianyu, Zori, Laith, Hegde, Shreyas, Kielb, Robert E., Campregher, Rubens
Format: Proceeding Journal
Bahasa: eng
Terbitan: , 2018
Subjects:
Online Access: https://zenodo.org/record/1345566
Daftar Isi:
  • The forced response behaviour of a rotor in a 3.5 - stage compressor rig is studied in this paper. Previous study indicates that the unsteady wave reflection level can highly influence forced response prediction results. Though traditional non - reflecting boundary conditions or mesh treatments can reduce the reflecting waves in the calculation efficiently, in physics the waves will reflect when interacting with the up - and downstream unstimulated bladed rows and non - reflecting is still an approximation. The downstream reflection was identified to have significant influence on the unsteady pressure of the simulated domains. Thus, the aim of this paper is to investigate the potential reflection effect and the consequent influence of forced response due to bladed rows. As an extension of our 3 - row stator - rotor - stator (S1 - R2 - S2) forced response simulation, a 4 - row (S1 - R2 - S2 - R3) simulation is conducted to test the influence of 1T - 44EO wave reflected from R3 back to R2 domain . Difference is seen compared with the case without the R3 domain, and a destructive interference is observed on forced response behaviours. Two conclusions are drawn from this study: 1) Wave excitation created by downstream stator s can reflect upstream due to the existence of the rotor row further downstream. The excitation interacts with the two traditional excitation sources, wake and potential field. In this case, the interaction is destructive and leads to a lower modal force prediction. 2) This reflection from down - stream row has a significant influence on the prediction of forced response, whereas upstream reflection is not significant. 3) The cut - on nature of the wave in this case also contributes to the reflection, as the wav e propagates without deterioration. This research also provides a guidance of forced response multi - row modeling.