Dynamics of flexible bodies in rotation, gyroscopic phenomena. Bending and torsional vibrations of rotors. Linear harmonic analysis (eigenvalues, eigenmodes in rotating machines, critical speeds), Campbell diagrams, application of Finite Element Method in rotors, dynamic analysis of multiple body systems with local nonlinearities, application of Model Order Reduction techniques, stability criteria in multiple DOF systems, damping models, characteristics of trajectories and response time series (periodicity, quasi-periodicity, chaos) in rotating machines, tribology in sliding bearings (Reynolds equation), design of sliding bearings and gas foil bearings, squeeze film dampers, base excitation in machines, parametric excitation (anisotropic rotors in generators), self-excited vibrations from fluid and gas flow (oil whirl/whip, Thomas/Alford forces) and dynamic stability. Standards and templates in dynamic analysis of turbomachines. Simulation of rotating machines. Projects: Basic rotor dynamic calculations for turbomachinery design, e.g. turbine-generator for power generation, turbopump for rocket propulsion, turbochargers in internal combustion engines, gear boxes, power transmission layouts.
- Teacher: Αθανάσιος Χασαλεύρης
ECTS : 5
Language : el, en
Learning Outcomes : Knowledge
Identify and describe the fundamental principles of rotating system dynamics and the behavior of machines operating over wide speed ranges.
Explain the operating principles and dynamic performance of fluid-film bearings, air bearings, rolling-element bearings, and active magnetic bearings.
Analyze the characteristics of linear and nonlinear rotor models, including mechanisms of excitation, damping, and dynamic instability.
Describe the relevant ISO and API standards governing the design and rotordynamic assessment of rotating machinery.
Skills
Model rotating systems of varying complexity, from simple 4-DOF representations to multi–degree-of-freedom finite element (FEM) models.
Compute harmonic response, natural frequencies, mode shapes, critical speeds, and modal damping using linear dynamic analysis methods.
Perform simulations of forced bending and torsional vibrations using computational tools (MATLAB, Python, FEM software).
Evaluate the influence of bearing selection on the dynamic response of rotating systems.
Apply closed-loop control schemes for active magnetic bearings to suppress rotor vibrations.
Competences (Autonomy & Responsibility)
Integrate a complete rotordynamic analysis and design workflow, consistent with industry practice.
Assess the structural integrity, operability, and reliability of a rotating machine based on rotordynamic analysis results and applicable standards.
Develop and document computational simulation projects in which the student interprets, justifies, and presents the dynamic behavior of a realistic rotating machine.
Work independently and collaboratively to carry out high-fidelity engineering analyses, making informed use of scientific literature, standards, and simulation tools.