statistical vibroacoustics and entropy concept统计声和熵的概念.pdf

Entropy 2010, 12, 2418-2435; doi:10.3390/ OPEN ACCESS entropy ISSN 1099-4300 /journal/entropy Article Statistical Vibroacoustics and Entropy Concept Alain Le Bot 1,, Antonio Carcaterra 2 and Denis Mazuyer 1 1 Laboratoire de Tribologie et Dynamique des Sysemes CNRS, Ecole Centrale de Lyon, 36, av. Guy de Collongue, 69134 Ecully, France; E-Mail: denis.mazuyer@ec-lyon.fr 2 Department of Mechanics and Aeronautics, University of Rome ’La Sapienza’, Via Eudossiana, 18, 00184 Rome, Italy; E-Mail: a.carcaterra@dma.ing.uniroma1.it Author to whom correspondence should be addressed; E-Mail: alain.le-bot@ec-lyon.fr; Tel.: +33-4-72-18-62-75; Fax: +33-4-78-43-33-83. Received: 20 November 2010; in revised form: 8 December 2010 / Accepted: 9 December 2010 / Published: 13 December 2010 Abstract: Statistical vibroacoustics, also called statistical energy analysis (SEA) in the field of engineering, is born from the application of statistical physics concepts to the study of random vibration in mechanical and acoustical systems. This article is a discussion on the thermodynamic foundation for that approach with particular emphasis devoted to the meaning of entropy, a concept missing in SEA. The theory focuses on vibration confined to the audio frequency range. In this frequency band, heat is defined as random vibration that is disordered vibration and temperature is the vibration energy per mode. Always in this frequency band, the concept of entropy is introduced and its meaning and role in