A review on dynamic characteristics of blade–casing rubbing

Blade–casing interaction/rubbing can occur under the small blade-tip clearance, which may lead to the rubbing damage, excessive wear of the abradable coating, and efficiency loss caused by the increasing tip leakage flow. Moreover, the rubbing process involves complicated dynamic phenomena, such as friction-induced wear and heat, coupling vibration of the blade and elastic casing, which has recently received a great concern. This paper provides a review on the dynamic characteristics of blade, rotor, and casing as well as the mechanism of coating wear when the rubbing between the blade and bare or coating casing occurs. Firstly, the modeling methods for blade–casing rubbing are categorized into three types in accordance with different casing types, namely models for the rubbing between the blade and bare casing, models for the rubbing between the blade and coating casing without considering wear, and models for the rubbing between the blade and coating casing considering wear. Then, the simulated blade–casing dynamic characteristics due to rubbing are described for both bare and coating casings. After that, the experimental results of the blade–casing rubbing are reviewed and summarized for the bare and coating casings, respectively. Finally, the open problems for blade–casing rubbings are stated, and some recommendations for future research are also pointed out.