Impact of smooth flow path junctions in resonator systems on hydraulic cylinder damping performance

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School of Engineering | Master's thesis

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Date

2024-12-23

Department

Major/Subject

Mechatronics

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Degree programme

Master's programme in Mechanical Engineering

Language

en

Pages

54

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Abstract

The papermaking industry heavily relies on the precision and consistency of the paper winding process to ensure high-quality products. A crucial aspect of this process is the efficient control of vibrations within the hydraulic systems used to support the rider roll beam. These systems sometimes employ hydraulic resonators designed to dissipate vibrations, ensuring consistent roll quality. The points where hydraulic lines converge, known as junctions, are hydraulic accessories where fluid energy can be wasted. These are generally used to connect the resonators to the main system. Traditional sharp-cornered junctions in hydraulic systems, used for mounting resonator components and elsewhere, introduce turbulence, flow separation, and energy losses, potentially compromising the efficiency of vibrational damping components. This thesis investigates whether smoothing these junctions can enhance the damping performance of resonators connected through them. The methodology involves an experimental setup with three junction types—sharp Y-junction, smooth Y-junction, and traditional T-junction—subjected to pulsatile and oscillatory flow conditions. Various combinations of control methods, flow conditions, and frequencies were tested to measure pressure fluctuations, impedance, and damping performance. Experimental results show that the smooth Y-junction tends to achieve lower hydraulic impedance, indicating fewer flow restrictions, and maintains more consistent pressure ratios compared to sharp-cornered junctions. However, the differences in measurements were relatively small under the specific scale and conditions of this study. While the smooth junction demonstrated some improvements in the system's performance, the numerical differences were modest and may not be substantial enough to justify widespread application across all scenarios.

Description

Supervisor

Vepsäläinen, Jari

Thesis advisor

Kajaste, Jyrki

Keywords

hydraulic systems, junction geometry, hydraulic resonators, vibration damping, paper winding, oscillatory flow

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Permanent link to this item

https://urn.fi/URN:NBN:fi:aalto-202501221579

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[dipl] Insinööritieteiden korkeakoulu / ENG