Fluid-induced instabilities such as whirl and whip are critical self-excited vibration phenomena that challenge the reliability of high-speed rotating machinery. These instabilities arise from the dynamic interaction between the rotor and the circumferential fluid in bearings, seals, or any configuration where two cylinders rotate with fluid in the gap. Whirl typically manifests as a rigid-body forward precession orbit at frequencies near fluid resonance (λΩ) tracking with ma

Steam turbines are subjected to extreme thermal expansion due to high operating temperatures, which can lead to excessive vibration amplitudes and/or elevated bearing metal temperatures. Uneven thermal expansion can cause casing distortion, misalignment, and pipe strain, and in some cases may even lead to rotor–casing rubbing. These conditions may prevent the unit from reaching normal operating states, resulting in penalties within the power generation industry. Thermal (load

Subsynchronous rub simulated in rotor kit with rubbing screw Rubbing occurs when rotating machine parts come into contact with stationary components. It is one of the most frequent malfunctions in rotating machinery, yet remains difficult to diagnose because vibration responses may appear as subsynchronous, synchronous, or supersynchronous (including harmonics). Accurate diagnosis requires a clear understanding of vibration characteristics, machine configuration, and dynamic

Torsional vibration is often overlooked in field measurements due to installation challenges, limited reliability of instrumentation, and complexities in signal processing. However, torsional effects can couple into lateral (radial) vibration through gear mesh interactions, making them observable in conventional vibration data. This paper discusses the manifestation of torsional–lateral coupled vibration, excitation sources, measurement methodologies, and modeling approaches,

Operating Deflection Shape (ODS) analysis is a highly effective technique for diagnosing and identifying the root causes of structural...

This article explains how to determine cause of journal bearing damage with erosion pattern as shown above. Introduction: As a machinery...

In this article, a case study of defective rolling element bearing detection will be discussed. Figure 1 - Bearing Inner Race The machine...

A back-pressure steam turbine that drives a 12 MW generator, experienced intermittent spikes in shaft vibration amplitudes at the...

We were engaged to perform vibration measurement and analysis of a 260 MW Francis turbine and generator and recommended a solution to...

We were engaged to perform vibration measurement and analysis of a 41 MW steam turbine and generator as the excessive vibration amplitude...

We regularly conduct the following courses for local as well as international customers. We believe the contents of these three main...

We will finish this year with three training courses below before we could celebrate new year and take some breaks for vacation. We got...

I am very delighted that we could make this last month for around 20 students in the class. This project was committed since last year...

We were participating CBM Day 2022 in Chonburi, Thailand as an exhibitor during 7-8 July. Our highlighted products this year are...

We conducted training course during 13 to 15 June 2022 for users who purchased motion amplification (MA) camera, a product of RDI...

Recently, we did torsional vibration measurement on a disk-pack coupling of 315 kW induction motor driven flue gas blower. A strain gauge...

The country is fully re-opened now after pandemic so we planned to arrange this session again in Q3 this year. We had a few participants...

We regularly conduct the following courses for local as well as international customers. We believe the contents of these three main...

A steam turbine-generator set was overhauled for about two (2) months before it was attempted to put back to services again. However,...

This is mandatory for power generation and petrochemical plants overhaul as vibration data must be collected at before and after overhaul...