1D FEM for Rotor Thermal Bow Calculation

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21220%2F22%3A00360293" target="_blank" >RIV/68407700:21220/22:00360293 - isvavai.cz</a>

Result on the web

<a href="https://www.fs.cvut.cz/ustavy/sekce-centrum-leteckeho-a-kosmickeho-vyzkumu/centrum-leteckeho-a-kosmickeho-vyzkumu-12203/centrum-12203/" target="_blank" >https://www.fs.cvut.cz/ustavy/sekce-centrum-leteckeho-a-kosmickeho-vyzkumu/centrum-leteckeho-a-kosmickeho-vyzkumu-12203/centrum-12203/</a>

DOI - Digital Object Identifier

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Result language

angličtina

Original language name

1D FEM for Rotor Thermal Bow Calculation

Original language description

Due to the operating conditions, the rotor and stator systems of the gas turbine are subjected to uneven thermal loading during the operation. Then, the thermal deformation has a more significant effect on the construction of the rotor part operating at rotating up to 60,000 RPM. In the case of a rotor system, all the components of the generator are further connected by a single shaft, which has a significant effect on the possibility of defining the clearances. The effect of the deformation on the stator part is negligible due to the construction, since the clearance limitation is achieved by the separation of the contact surfaces or the possibility of bending the cover plates of the flow primary gas path. The deformation influence of the rotor system then has a fundamental effect on the safe operation of the gas turbine. Possible contact between the rotor and stator system can damage the engine or reduce its efficiency due to increased radial clearance. Not only these factors show the requirement for thermal deformations in the development and design of a turboprop engine. The paper will show a simplified 1D FEM model of a rotor system operating in one operating mode. Due to this mode, the axial deformation and the deflection line of the loaded rotor will be monitored. Finally, the effect of bearing damage and prevention of bearing displacement will be monitored.

Czech name

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Czech description

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Type

R - Software

CEP classification

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OECD FORD branch

20304 - Aerospace engineering

Project

<a href="/en/project/EF16_019%2F0000826" target="_blank" >EF16_019/0000826: Center of Advanced Aerospace Technology</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Internal product ID

12203_CASR_Parez_RTB_1D

Technical parameters

The finite element method was used to build the 1D calculation model. This is a discretization method. The modeling is based on the selected dimensions of the gas generator rotor system. The modeled system is appropriately discretized into elements. The used element is a beam element with two nodes i and i+1. In each of the nodes, there are a total of three degrees of freedom: displacement in the x-axis - w, displacement in the y-axis - v, and rotation φ. The individual elements of each computational model are characterized by two geometric parameters. The outer diameter of the shaft and the length of the element were entered for each element. Material constants were assigned for each element. For each element, the quadratic moment of the cross-sectional area was calculated from the outer diameter of the given element. First, the temperature field was determined using temperature matrices ???? with two temperatures for boundary conditions on the first and last nodes and equality of heat conduction ???? in the shaft. Furthermore, stiffness matrices ???????? were compiled for individual elements, from which global stiffness matrice ???????? were compiled. The computational model is made of one isotropic material, which is steel. The material properties are Young's modulus of elasticity in tension. The entire rotor model consists of a compressor, combustor, and turbine. These are then connected by a shaft and supported in bearings. The bearings are considered in the calculation models as isotropic point supports, by adding the condition of shaft deflection to the appropriate node. The result is the deflection of the rotor system depending on the defined parameters.

Economical parameters

The economic benefit of the developed software is possible in the case of its use in the design of rotor systems as well as in the case of monitoring the behavior of systems in operation. The software works on the basis of Matlab scripts. The input parameters are selectable without significant restrictions.

Owner IČO

68407700

Owner name

České vysoké učení technické v Praze / FS / centrum leteckého a kosmického výzkumu