ABSTRACT:
One of the critical challenges in radial turbine design and manufacturing is ensuring vibration control and operational stability, particularly due to the high-speed rotation of the components involved. To address this, a comprehensive rotor dynamic analysis was conducted on a rotor-bearing system of a 1 kWe radial inflow turbine. The primary aim was to identify a system configuration that supports stable operation during the design phase. The rotor and blade geometries were developed using CATIA, which facilitated the extraction of precise mass and inertia data necessary for the dynamic simulation. ANSYS Workbench was employed to create a simulation model incorporating rotational velocity and remote displacement to mimic real-world operating conditions. Both modal and mass unbalance response analyses were performed for two configurations with varying shaft lengths and bearing arrangements. The more stable configuration was selected for a detailed parametric study, analyzing how variations in shaft length, blade residual unbalance, and bearing stiffness influenced blade displacement amplitude. Based on this analysis, the blade clearance was defined, enabling the establishment of optimal parameters for shaft length, bearing setup, unbalance tolerance, and stiffness to ensure reliable and efficient turbine performance.
Aim:
The aim of this study is to perform rotor dynamic analysis on a 1 kWe radial inflow turbine to determine an optimal rotor-bearing system configuration that ensures vibration stability and reliable performance, by evaluating the effects of shaft length, blade unbalance, and bearing stiffness on blade displacement amplitude.
Objective:
The objective of this study is to evaluate and optimize the rotor-bearing system of a 1 kWe radial inflow turbine for stable and vibration-free operation. This involves conducting rotor dynamic analysis to investigate the influence of key parameters such as shaft length, blade residual unbalance, and bearing stiffness on the dynamic behavior of the rotor system. Using detailed rotor and blade models developed in CATIA, mass and inertia properties were obtained and integrated into a simulation environment in ANSYS Workbench. Modal and unbalance response analyses were carried out for different shaft and bearing configurations to identify the most stable setup. The selected configuration was then subjected to a parametric study to determine acceptable design limits for blade displacement amplitude, thereby guiding the selection of appropriate shaft dimensions, bearing types, unbalance quality, and blade clearance to ensure efficient and safe turbine operation.
