Acoustic Identification of Turbocharger Impeller Mistuning—A New Tool for Low Emission Engine Development

Abstract

At present, exhaust gas turbochargers not only form the basis for the economical operation of petrol, diesel or gas engines of all power categories, but also have an irreplaceable role on reducing their emissions. In order to reduce emissions from internal combustion engines, various systems are being developed, all of which have a turbocharger as an important component. Demands on turbocharger system durability and reliability keep growing, which requires the application of increasingly advanced computational and experimental methods at the development beginning of these systems. The design of turbochargers starts with a mathematical description of their rotationally cyclic impellers. However, mistuning, i.e., a slight individual blade property deviation from the intended design parameters, leads to a disturbance of the rotational cyclic symmetry. This article deals with the effects of manufacturing-related deviations on the structural dynamic behaviour of real turbine rotors. As opposed to methods exploiting expensive scanning vibrometers for experimental modal analysis or time-consuming accurate measurement of the geometry of individual blades using 3D optical scanners. A suitable microphone and a finite element rotor wheel model are the basis of this new method. After comparing the described acoustic approach with the laser vibrometer procedure, the results seemed to be practically identical. In comparison with the laser technique the unquestionable added value of this new method is the fact that it brings a significant reduction in the financial requirements for laboratory equipment. Another important benefit is that the measuring process of bladed wheel mistuning is significantly less time-consuming.

Acoustic Method for Estimation of Marine Low-Speed Engine Turbocharger Parameters

“…This results in a change in the flow capacity of the exhaust manifolds as well as the character of the gas internal flow in front of the turbocharger wheel blades. Pulsations might occur, which cause the rotor to vibrate [8][9][10]. An increased level of rotor vibration creates additional loads on turbocharger bearings and reduces their operational life.…”

“…Acoustic control of the turbocharger in operation makes it possible to detect the dangerous tendency for the rotor vibration level to increase and indicates the need to clean the flow channel [8][9][10][11]. In some cases, such control might prevent turbocharger failure, which typically leads to a considerable loss of power and efficiency in the entire engine [1,[11][12][13][14].…”

Reliability Modeling and Analysis of a Diesel Engine Design Phase Based on 4F Integration Technology

“…Therefore, it is necessary to focus on improving the reliability of vehicle diesel engines. The most effective way to improve the working reliability of a diesel engine is to introduce the concept of reliability at the design stage [2] and to prevent potential hazards by using the corresponding reliability calculations and analyses (reducing the costs of product manufacture and improving the reliability of the product life cycle in the process). In this regard, the reliability analysis and its management at the design stage are particularly important.…”

Віброакустична Діагностика Турбокомпресора Суднового Дизельного Двигуна

“…This results in the change of the flow capacity of the exhaust manifolds as well as the character of the gas internal flow in front of the blades of the turbocharger wheel. Pulsations might occur, which causes the rotor to vibrate [8][9][10]. Increased level of rotor vibration creates additional loads on turbocharger bearings and reduces their operational life.…”

“…Vibroacoustic control of the turbocharger in operation makes it possible to detect the dangerous tendency of the vibration level increase of the rotor and indicate the need for cleaning the flow channel [8][9][10][11]. In some cases, such control might prevent turbocharger failure, which typically leads to a considerable loss of power and efficiency of the entire engine [1; 11-14].…”