Validation in water of a new methodology for the vibrational analysis of rotating components in a high-density fluid

Kamiel Ceusters, Mikhail Iarmonov, Kirill Makhov, Katrien Van Tichelen, Michiel Van Damme, Henri Dolfen, Nicolas Delaissé, Tom Verstraete, Joris Degroote

Research outputpeer-review

Abstract

In this paper a methodology is developed to study the vibrational characteristics of rotating components in high density fluids. Such high-density fluids cause large added mass and added damping effects compared to the situation
in vacuum, which can drastically alter the vibrational behaviour of the mechanical components. Due to the increased interest in these fluids as coolants for fourth generation nuclear facilities, their effect on the vibrational behaviour of
rotating machines such as reactor pumps must be better understood. As an example, MYRRHA, the nuclear research facility currently being developed by SCK CEN, uses high-density lead-bismuth eutectic as primary coolant. Hence,
a new approach is required to predict vibrations in the primary pump of MYRRHA. Due to the complex geometry of the pump, with flow in a rotating frame of reference, in combination with the lack of experimental data, the focus in the development of the new approach is first placed on a more simple configuration in water, for which experimental data is available in literature. The methodology is based on a combination of multiple numerical simulations to obtain the vibrational behaviour. In the first step, it uses a structural solver to obtain the vibration modes of the structure in vacuum. Next, a fluid-structure interaction simulation is performed, where the modal characteristics are extracted from the displacement by performing a curve fitting procedure. By comparing the displacement of the structure in vacuum and in the fluid, the added mass and added damping effects can be obtained.
Additionally, forces can be introduced on the structure or in the flow to study the effects of fluid and mode coupling.
Original languageEnglish
Title of host publication20th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH 20)
Subtitle of host publicationFluid-Structure Interactions
PublisherAmerican Nuclear Society
Pages4384-4396
Number of pages13
DOIs
StatePublished - 20 Aug 2023

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