Nonlinear Dynamics of a Blade Rotor with Coupled Rubbing of Labyrinth Seal and Tip Seal

Abstract

The dynamic response and its stability of a blade rotor with coupled rubbing in the labyrinth seal and tip seal are investigated. The dynamic equations are established based on the Hertz contact rubbing force at the labyrinth seal and the tip rubbing force considering both the contact deformation of the tip seal and the bending deformation of the blade. Numerical simulations show that the coupled rubbing response includes periodic motions, almost periodic motions, and chaotic motions. Compared with the single rubbing fault, coupled rubbing increases the range of rotation velocity of contact. A new continuation shooting method is used in the solution and stability analysis of the periodic response to give the bifurcation diagrams. The paths of the system for entering and exiting chaos are analyzed.

Thermomechanical Transient Dynamics of Radial Rotor-Stator Contact

“…Instead, in-phase unbalance yields forward full annular rub. Zhang [53] studied periodicity and stability of a turbine shaft when coupled frictional contacts at labyrinth seal and blade tip levels take place initiated by unbalance on the blisk.…”

Dynamic Strain Measurement of Rotor Blades in Helicopter Flight Using Fiber Bragg Grating Sensor

“…where f is the measurement frequency of the FBG sensor, and v is the travel velocity of the strain wave in the measured structure material. There is also the following formula for FBG sensors: λ = nl 0 (10) Substituting Equation (10) into Equation ( 9), we obtain…”

“…A fiber Bragg grating (FBG) sensor, as an optical signal sensor, is essentially different from a resistance strain gauge, and it has a lot of advantages such as a long-term stability, a strong corrosion resistance, a small volume, a light weight, a high sensitivity, a strong resistance to electromagnetic interference, a broad transmission band, a large communication capacity, a low transmission loss, insulation, no electric spark, small leaks, and a strong confidentiality; it has been widely used in many fields, such as: a bridge motion system for measuring the vehicle parameters based on strain measurement using FBG sensors [ 1 ], an FBG sensing application in an arch dam model test [ 2 ], and the monitoring of a coal mine roadway roof based on FBG displacement sensors [ 3 ] in the field of civil engineering; fault detection of an FBG sensing system on airplanes [ 4 ], landing-gear load measurement using a wide-range FBG strain sensor [ 5 ], border detection application via temperature, strain, and pressure using FBG [ 6 ], and FBG sensors for aircraft wing-shape measurement [ 7 ] in the field of airplane engineering; FBG data treatment aimed at eliminating the noise in the strain sensor data induced by vibrations of the helicopter blade in flight conditions [ 8 ], helicopter bearing detection technology using FBG acoustic emission technology [ 9 ], and blade vibration load characteristic measurement using FBG by the authors [ 10 ] in the field of helicopter engineering; and FBG-based acoustic emission measurement [ 11 ] and a laser self-mixing FBG sensor for acoustic emission measurement [ 12 ] for structural health monitoring.…”

On the operational similarities of bladed rotor vibrations with casing contacts

“…As the clearance diminishes, the probability of contact between the blades and casing increase [6]. The blade casing contact will lead to complex dynamics of the rotating machine based on the design and operational parameters [7][8][9]. The dynamics models develop for blade-tip contacts will depend on the goal of the research studies.…”