Control Method Of Thermoacoustic Instability With Acoustic Liner With Heating Bias Flow

Thermoacoustic instability is a common problem that can easily occur in gas turbines and the combustion chambers of aerospace engines,often resulting in structural damage.Therefore,it is necessary to study the mechanism of thermoacoustic instability and effective control methods.This paper mainly studies the characteristics of thermoacoustic instability and its control methods.A horizontally placed Rijke tube experimental platform with heating wire as a heat source was built.Based on this experimental platform,the thermoacoustic instability characteristics were studied in detail by changing different air flows and different heating power.The steady-state and non-steady-state characteristics of the thermoacoustic instability of the system were found in the experiment,and the results of the quasi-static and rapid changes of the heating wire power were obtained.And then,the control method of thermoacoustic instability is studied.The perforated plate acoustic lining is used to control the thermoacoustic instability of the Rijke tube.In the experiment,two sets of sound linings were designed to two rows of holes and four rows of holes.In general,the sound lining will be with a bias current to enhance the control effect.In this study,different flow rates bias flow was injected into the sound lining.at the same time,the bias flow was heated to 100 °C,200 °C,and 300 °C,respectively.The experiment found that the sound lining has a very good inhibitory effect on thermoacoustic instability.In addition,the bias flow can significantly enhance the suppression effect on thermoacoustic instability.However,the bias flow temperature is not very significant for improving the control effect.