Aero and Vibroacoustics of Automotive Turbochargers by Hung Nguyen-Schäfer

By Hung Nguyen-Schäfer

Aero and Vibroacoustics of automobile Turbochargers is a subject related to facets from the operating fields of thermodynamics of turbomachinery, aerodynamics, rotordynamics, and noise propagation computation.

In this commonly interdisciplinary topic, thermodynamicsof turbomachinery is used to layout the turbocharger and to figure out its working stipulations. Aerodynamics is required to review the compressor move dynamics and movement instabilities of rotating stall and surge, which may produce growling and whining-type noises. Rotordynamics is critical to check rotor unbalance and self-excited oil-whirl instabilities, which result in whistling and relentless tone-type noises in rotating floating oil-film kind bearings. For the specified case of turbochargers utilizing ball bearings, a few high-order harmonic and put on noises additionally show up within the rotor working diversity. finally, noise propagation computation, based on Lighthill’s analogy, is needed to enquire airborne noises produced via turbochargers in passenger vehicles.

The content material of this e-book is meant for complicated undergraduates, graduates in mechanical engineering, examine scientists and training engineers who are looking to greater comprehend the interactions among those operating fields and the ensuing influence at the fascinating subject of Aero and Vibroacoustics of automobile Turbochargers.

Show description

Read Online or Download Aero and Vibroacoustics of Automotive Turbochargers PDF

Best acoustics & sound books

Noise reduction in speech processing

Noise is far and wide and in so much purposes which are relating to audio and speech, corresponding to human-machine interfaces, hands-free communications, voice over IP (VoIP), listening to aids, teleconferencing/telepresence/telecollaboration platforms, and such a lot of others, the sign of curiosity (usually speech) that's picked up by means of a microphone is mostly infected through noise.

Understanding and Crafting the Mix, : The Art of Recording

Realizing and Crafting the combination supplies transparent and systematic equipment for deciding on, comparing, and shaping the creative components in tune and audio recording. The routines all through assist you to enhance severe listening and comparing abilities and achieve larger keep watch over over the standard of your recordings.

Noise Control From Concept to Application

A great studying device for college kids and practitioners, this consultant to noise keep an eye on will allow readers to take advantage of their wisdom to resolve quite a lot of commercial noise regulate difficulties. operating from simple medical ideas, the writer indicates how an knowing of sound might be utilized to real-world settings, operating via a number of examples intimately and protecting solid perform in noise regulate for either new and current amenities.

Additional resources for Aero and Vibroacoustics of Automotive Turbochargers

Example text

3:31cÞ 26 3 Acoustic Propagation Theory In the case of inviscid flows at low Reynolds numbers and small perturbation amplitudes in an isentropic process for linear acoustics, all rhs terms in Eqs. 31b) equal zero. 31a) in the perturbed pressure becomes the LEE given in Eq. 29a). The acoustic propagation equation LEE of the average noise pressure p0 is written in the radial direction r.   0 o2 p0 c20 o 2 op r À ¼0 ð3:32Þ ot2 r 2 or or Substituting a new unknown variable m = p0 Ár into Eq. 32), one obtains the acoustic propagation equation LEE in the radial direction after a few arithmetic calculations.

1 Aerodynamic Noise 51 ω >0 → β1 0 2 β2 → cu , 2 > 0 wu , 2 < 0 cu ,1 > 0 wu ,1 < 0 0 1 r2 → ci = wi + ui → → 1 r1 u1 β1 < 0 c → α1 > 0 u2 → 2 → w1 → cm , 2 c α2 > 0 w2 β2 < 0 Fig. 5 Velocity triangle map of a radial compressor wheel (CW) The Euler’s turbocharger equation is formulated in PC ¼ ðu2 cu;2 À u1 cu;1 Þ m_ C Ã 1Â ¼ ðc22 À c21 Þ þ ðu22 À u21 Þ À ðw22 À w21 Þ 2 WC  ð4:7Þ where w2 \ w1 because the outlet air density is larger than the inlet air density in case of compressors. 75 if the compressor performance is fulfilled according to De Haller’s rule [1, 8].

1. To generate the LSB frequencies, one superimposes the excitation frequency f2 on (2f2 - f1) to obtain the second-order frequency (3f2 - f1) following the thin arrow, and superimposing f2 again on the second-order frequency to generate the 44 3 Acoustic Propagation Theory third-order frequency (4f2 - f1). Another way, following the dark arrow, one obtains the new high-order harmonic frequencies of 2f2 and 3f2 by adding f2 to itself and 2f2, respectively. In order to receive the third-order frequency (2f2 ?

Download PDF sample

Rated 4.01 of 5 – based on 31 votes

Categories: Acoustics Sound