ITS is active in acoustics Research and Development (R&D), with many contents produced by ITS human ressource.

Papers in relation to the acoustic properties of multilayered structures (planes or orthotropic partitions), made of plates and of porous media, play an important role here, with respect to their acoustic absorption as useful for reducing the reverberation of industrial or tertiary premises (acoustic correction) or for the reduction of noise by means of dissipative mufflers (e.g. for ventilation and air-conditioning systems, for the suction and discharge of fans, engines and turbo-machineries), or with respect to their acoustic absorption and their ability to limit sound transmission, which is sought for acoustic insulation panels (e.g. for machine enclosures, noise barriers and walls in industry, metal cladding in the construction or for claustras intended for offices or canteens).

Reports concerning research and development (R&D) works related to the acoustics and aerodynamics of fluid networks (under pressure when not conventional air systems) are numerous, both in terms of the performance of subsets such singularities such as ducts of different geometries, elbows, chimneys, nozzles, silencers of all kinds (which must be modeled for a correct consideration of their sound impact) as for the noise emitted by valves or gaseous jets including safety valves, and also for associated discharge parameters.

In addition, various documents deal with the propagation of sound, either outdoors (in relation to atmospheric absorption or to the presence of obstacles), or in premises (in relation to the phenomenon of reverberation) for problems related to noise decay (spatial or temporal).

ITS's research and development (R&D) works in acoustics (based on measurements and on simulations by the means of computation software with in-house programming), all related to the development of soundproofing products, devices and systems for building and industry, are the scientific background of ITS services offerings in the field of insulation and are illustrated by the contents produced and updated, over time, by the human resource of ITS.

  • Report PhRxx-000x Comparisons between measurements and predictions of the properties of dry air in terms of thermodynamics and fluid dynamics (2017)
  • Report PhRxx-005x Review of the computation scheme of dissipative silencers (2008)
  • Report PhRxx-006x Acoustic development program for ITS: aperiodic report of the implementation (2020)
  • Report PhRxx-007x Comparisons between measurements and prediction with a 5-parameters model for the COmputation of Acoustic Layers (2008)
  • Report PhRxx-008x User’s manual for the software SILDIS® (2020)
  • Report PhRxx-009x Overview of the properties of some materials in the context of the design of sound proofing equipments involving porous media (2008)
  • Report PhRxx-011x Acoustic and aeraulic design of dissipative silencers: the status of the Art (2019)
  • Report PhRxx-012x Comparisons between measurements and predictions of the transmission loss of a single-leaf (plane) partition consisting of a monolithic, isotropic plate (and related considerations) (2014)
  • Report PhRxx-013x Sound Impact Limitation Design for Industrialized Solutions: a single Excel based software for a wide range of applications (presentation brochure for the software SILDIS®) (2017)
  • Report PhRxx-014x Procedure for the use of Excel based programs with a restricted access (2008)
  • Report PhRxx-015x Collection of soundproofing constructions systems: a companion to “User’s manual for the software SILDIS®” (20xx)
  • Report PhRxx-016x Comparisons between measurements and predictions of the sound absorption of a multilayered (plane) acoustic structure (2020)
  • Report PhRxx-017x Comparisons between measurements and predictions of the sound transmission of a single-leaf (plane) partition consisting of a porous medium (2009)
  • Report PhRxx-018x Comparisons between measurements and predictions of the sound transmission of a single-leaf (plane) partition consisting of a monolithic, orthotropic plate (2009)
  • Report PhRxx-020x Comparisons between measurements and predictions of the sound transmission of  a (plane) partition consisting of a monolithic, isotropic plate covered by a porous medium (2009)
  • Report PhRxx-023x Acoustic design of plane partitions: the status of the Art (2009)
  • Report PhRxx-024x Comparisons between measurements and predictions of the sound transmission of a double-leaf (plane) partition consisting of 2 monolithic, isotropic plates (2009)
  • Report PhRxx-025x Comparisons between measurements and predictions of the sound transmission of a double-leaf (plane) partition consisting of 1 monolithic, isotropic plate and 1 monolithic, orthotropic plate (2009)
  • Report PhRxx-026x Comparisons between measurements and predictions of the sound transmission of a triple-leaf (plane) partition consisting of (3) monolithic, isotropic plates (2009)
  • Report PhRxx-027x Comparisons between measurements and predictions of the sound transmission of a (plane) plate with an extensional damping (2009)
  • Report PhRxx-030x Sécurisation du programme de calcul SILDIS®  (2009)
  • Report PhRxx-031x Comparisons between measurements and prediction of the acoustic performance of rectangular dissipative silencers. Part 1: propagation loss with or without flow (2017)
  • Report PhRxx-032x Comparisons between measurements and predictions of the acoustic performance of rectangular dissipative silencers. Part 2: bypass correction (2017)
  • Report PhRxx-033x Comparisons between measurements and predictions of the acoustic performance of rectangular dissipative silencers. Part 3: reflection loss (2017)
  • Report PhRxx-034x Comparisons between measurements and predictions of the acoustic performance of rectangular dissipative silencers. Part 4: insertion loss without self noise (2020)
  • Report PhRxx-035x Comparisons between measurements and predictions of the acoustic performance of rectangular dissipative silencers. Part 5: self noise (2009)
  • Report PhRxx-036x Comparisons between measurements and predictions of the acoustic performance of rectangular dissipative silencers. Part 6: transmission loss with or without flow (2020)
  • Report PhRxx-037x Comparisons between measurements and predictions of the aeraulic performance of rectangular dissipative silencers.  (2013)
  • Report PhRxx-041x Comparisons between measurements and prediction of the acoustic performance of square dissipative silencers. Part 1: propagation loss with or without flow (2013)
  • Report PhRxx-047x Comparisons between measurements and predictions of the aeraulic performance of square dissipative silencers. (2009)
  • Report PhRxx-051x Comparisons between measurements and prediction of the acoustic performance of round dissipative silencers. Part 1: propagation loss with or without flow (2020)
  • Report PhRxx-055x Comparisons between measurements and predictions of the acoustic performance of round dissipative silencers. Part 5: self noise (2009)
  • Report PhRxx-057x Comparisons between measurements and predictions of the aeraulic performance of round dissipative silencers. (2009)
  • Report PhRxx-061x Comparisons between measurements and prediction of the acoustic performance of round dissipative silencers with a central pod. Part 1: propagation loss with or without flow (2020)
  • Report PhRxx-065x Comparisons between measurements and prediction of the acoustic performance of round dissipative silencers with a central pod. Part 5: self noise (2017)
  • Report PhRxx-067x Comparisons between measurements and predictions of the aeraulic performance of round dissipative silencers with a central pod (2017)
  • Report PhRxx-071x Comparisons between measurements and prediction of the acoustic performance of resonant silencers made of Pine Tree splitters with a rear lining. Part 1: propagation loss with or without flow (2009)
  • Report PhRxx-075x Comparisons between measurements and prediction of the acoustic performance of resonant silencers made of Pine Tree splitters with a rear lining. Part 5: self noise (2009)
  • Report PhRxx-081x Comparisons between measurements and prediction of the acoustic performance of resonant silencers made of Pine Tree splitters with a lateral lining. Part 1: propagation loss with or without flow (2009)
  • Report PhRxx-085x Comparisons between measurements and prediction of the acoustic performance of resonant silencers made of Pine Tree splitters with a lateral lining. Part 5: self noise (2010)
  • Report PhRxx-090x Comparisons between measurements and predictions of the acoustic performance of rectangular duct walls. Part 1: break-out sound transmission loss (2013)
  • Report PhRxx-091x Comparisons between measurements and predictions of the acoustic performance of circular duct walls.Part 1: break-out sound transmission loss (2018)
  • Report PhRxx-094x Comparisons between measurements and predictions of the acoustic performance of round bends. Part 1: insertion loss without self noise (2013)
  • Report PhRxx-095x Comparisons between measurements and predictions of the acoustic performance of round bends. Part 2: self noise (2013)
  • Report PhRxx-096x Comparisons between measurements and predictions of the acoustic performance of round bends. Part 3: insertion loss with self noise (2013)
  • Report PhRxx-100x Comparisons between measurements and predictions of the acoustic performance of rectangular ducts walls. Part 2: sound power level radiated by (duct) walls (20xx)
  • Report PhRxx-101x Comparisons between measurements and predictions of the acoustic performance of circular ducts walls. Part 2: sound power level radiated by (duct) walls (20xx)
  • Report PhRxx-104x Comparisons between measurements and predictions of the spatial decay of speech in open-plan offices (2015)
  • Report PhRxx-105x Comparisons between measurements and predictions of the sound spatial decay in industrial spaces (2015)
  • Report PhRxx-107x Comparisons between measurements and predictions of exhaust ducts directivity  (2015)
  • Report PhRxx-108x Comparisons between measurements and predictions of sound attenuation during propagation in air (2015)
  • Report PhRxx-111x Comparisons between measurements and predictions of control valves aerodynamic noise.Part 1: flow indicators (2016)
  • Report PhRxx-112x Comparisons between measurements and predictions of control valves aerodynamic noise. Part 2: noise level (2016)
  • Report PhRxx-115x Comparisons between measurements and predictions of the acoustic performance of rectangular bends. Part 2: self noise (2013)
  • Report PhRxx-117x Comparisons between measurements and predictions of control valves aerodynamic noise  (2016)
  • Report PhRxx-121x Comparisons between measurements and prediction of the acoustic performance of conventional splitter silencers versus silencers with discontinued splitters. Part 1: propagation loss with or without flow (20xx)
  • Report PhRxx-122x Comparisons between measurements and prediction of the acoustic performance of conventional splitter silencers versus silencers with discontinued splitters. Part 2: bypass correction (20xx)
  • Report PhRxx-123x Comparisons between measurements and prediction of the acoustic performance of conventional splitter silencers versus silencers with discontinued splitters. Part 3: reflection loss (20xx)
  • Report PhRxx-124x Comparisons between measurements and prediction of the acoustic performance of conventional splitter silencers versus silencers with discontinued splitters. Part 4: insertion loss without self noise (20xx)
  • Report PhRxx-125x Comparisons between measurements and prediction of the acoustic performance of conventional splitter silencers versus silencers with discontinued splitters. Part 5: self noise (20xx)
  • Report PhRxx-131x Comparisons between measurements and prediction of the acoustic performance of rectangular dissipative silencers with discontinued splitters. Part 1: propagation loss with or without flow (2016)
  • Report PhRxx-132x Comparisons between measurements and predictions of the acoustic performance of rectangular dissipative silencers with discontinued splitters. Part 2: bypass correction (20xx)
  • Report PhRxx-133x Comparisons between measurements and predictions of the acoustic performance of rectangular dissipative silencers with discontinued splitters. Part 3: reflection loss (20xx)
  • Report PhRxx-134x Comparisons between measurements and predictions of the acoustic performance of rectangular dissipative silencers with discontinued splitters. Part 4: insertion loss without self noise (20xx)
  • Report PhRxx-135x Comparisons between measurements and predictions of the acoustic performance of rectangular dissipative silencers with discontinued splitters. Part 5: self noise (2015)
  • Report PhRxx-137x Comparisons between measurements and prediction of the aerodynamic performance of rectangular dissipative silencers with discontinued splitters (2015)
  • Report PhRxx-139x On the comparison of the performance of silencers with continuous and discontinuous splitters: 2 case studies with the software SILDIS® (2018)
  • Report PhRxx-141x Comparisons between measurements and predictions of the acoustic performance of straight round ducts. Part 1: insertion loss without self noise (2013)
  • Report PhRxx-142x Comparisons between measurements and predictions of the acoustic performance of straight round ducts. Part 2: self noise (2013)
  • Report PhRxx-143x Comparisons between measurements and predictions of the acoustic performance of straight round ducts. Part 3: insertion loss with self noise (2013)
  • Report PhRxx-151x Comparisons between measurements and predictions of the acoustic performance of straight rectangular ducts. Part 1: insertion loss without self noise (2013)
  • Report PhRxx-152x Comparisons between measurements and predictions of the acoustic performance of straight rectangular ducts. Part 2: self noise (2013)
  • Report PhRxx-153x Comparisons between measurements and predictions of the acoustic performance of straight rectangular ducts. Part 3: insertion loss with self noise (2013)
  • Report PhRxx-161x Comparisons between measurements and predictions of nozzle reflection (2013)
  • Report PhRxx-171x Comparisons between measurements and predictions of sound decay in enclosed spaces. Part 1: temporal sound decay after noise-off (2014)
  • Report PhRxx-172x Comparisons between measurements and predictions of sound decay in enclosed spaces. Part 2: reverberation time (2018)
  • Report PhRxx-173x Comparisons between measurements and predictions of sound decay in enclosed spaces. Part 3: spatial sound decay (2018)
  • Report PhRxx-174x Comparisons between measurements and predictions of sound decay in enclosed spaces. Part 4: sound level reduction after acoustical treatment (2018)
  • Report PhRxx-175x Comparisons between measurements and predictions of sound decay in enclosed spaces. Part 5: rate of spatial sound decay of sound pressure levels per distance doubling (2018)
  • Report PhRxx-176x Comparisons between measurements and predictions of sound decay in enclosed spaces. Part 6: excess of sound pressure level (2018)
  • Report PhRxx-177x Comparisons between measurements and predictions of sound decay in enclosed spaces. Part 7: excess of sound pressure level at a specified distance (2018)
  • Report PhRxx-181x Comparisons between measurements and prediction of jet noise. Part 1: turbulence noise. Sub-part 1: acoustic efficiency (2016)
  • Report PhRxx-182x Comparisons between measurements and prediction of jet noise. Part 1: turbulence noise. Sub-part 2: sound power  (2016)
  • Report PhRxx-184x Comparisons between measurements and prediction of jet noise. Part 1: turbulence noise. Sub-part 4: spectrum (2016)
  • Report PhRxx-191x Comparisons between measurements and prediction of jet noise. Part 2: chocked jet noise. Sub-part 1: acoustic efficiency (2016)
  • Report PhRxx-192x Comparisons between measurements and prediction of jet noise. Part 2: chocked jet noise. Sub-part 2: sound power  (2016)
  • Report PhRxx-193x Comparisons between measurements and prediction of jet noise. Part 2: chocked jet noise. Sub-part 3: peak frequency (2016)
  • Report PhRxx-194x Comparisons between measurements and prediction of jet noise. Part 2: chocked jet noise. Sub-part 4: spectrum (2016)
  • Report PhRxx-202x Comparisons between measurements and prediction of jet noise. Part 3: undefined jet noise. Sub-part 2: sound power  (2016)
  • Report PhRxx-204x Comparisons between measurements and prediction of jet noise. Part 3: undefined jet noise. Sub-part 4: spectrum (2016)
  • Report PhRxx-211x Comparisons between measurements and prediction of jet noise. Part 1: spectrum of turbulence noise (20xx)
  • Report PhRxx-212x Comparisons between measurements and prediction of jet noise. Part 2: spectrum of shock noise (20xx)
  • Report PhRxx-213x Comparisons between measurements and prediction of jet noise. Part 3: power of unspecified noise (20xx)
  • Report PhRxx-221x Comparisons between measurements and predictions of safety valves noise (emissions). Part 1: flow indicators (2016)
  • Report PhRxx-222x Comparisons between measurements and predictions of safety valves noise (emissions). Part 2: noise level (2016)
  • Report PhRxx-230x Comparisons between measurements and predictions of piping systems flow indicators (2016)
  • Report PhRxx-241x Comparisons between measurements and prediction of the acoustic performance of simple expansion chamber muffers without extended tubes. Part 1: transmission loss with or without flow (2017)
  • Report PhRxx-242x Comparisons between measurements and prediction of the acoustic performance of simple expansion chamber muffers without extended tubes. Part 1: insertion loss with or without flow (2017)
  • Report PhRxx-251x Comparisons between measurements and prediction of the acoustic performance of simple expansion chamber muffers with inlet extended tube. Part 1: transmission loss with or without flow (2017)
  • Report PhRxx-261x Comparisons between measurements and prediction of the acoustic performance of simple expansion chamber muffers with outlet extended tube. Part 1: transmission loss with or without flow (2017)
  • Report PhRxx-271x Comparisons between measurements and prediction of the acoustic performance of simple expansion chamber muffers with inlet & outlet extended tubes. Part 1: transmission loss with or without flow (2017)
  • Report PhRxx-281x Comparisons between measurements and prediction of the acoustic performance of double expansion chamber muffers without extended tubes. Part 1: transmission loss with or without flow (2017)
  • Report PhRxx-291x Comparisons between measurements and prediction of the acoustic performance of double expansion chamber muffers with inlet extended tube. Part 1: transmission loss with or without flow (2017)
  • Report PhRxx-301x Comparisons between measurements and prediction of the acoustic performance of double expansion chamber muffers with outlet extended tube. Part 1: transmission loss with or without flow (2017)
  • Report PhRxx-311x Comparisons between measurements and prediction of the acoustic performance of double expansion chamber muffers with inlet & outlet extended tubes. Part 1: transmission loss with or without flow (2017)
  • Report PhRxx-321x Comparisons between measurements and prediction of the acoustic radiation of a termination being open & unflanged. Part 1: end correction (2017)
  • Report PhRxx-322x Comparisons between measurements and prediction of the acoustic radiation of a termination being open & unflanged. Part 2: reflection coefficient (2017)
  • Report PhRxx-323x Comparisons between measurements and prediction of the acoustic radiation of a termination being open & unflanged. Part 3: radiation impedance (2017)
  • Report PhRxx-331x Comparisons between measurements and prediction of the acoustic radiation of a termination being open & flanged. Part 1: end correction (2017)
  • Report PhRxx-332x Comparisons between measurements and prediction of the acoustic radiation of a termination being open & flanged. Part 2: reflection coefficient (2017)
  • Report PhRxx-333x Comparisons between measurements and prediction of the acoustic radiation of a termination being open & flanged. Part 3: radiation impedance (2017)
  • Report PhRxx-341x Comparisons between measurements and prediction of the acoustic radiation of a termination being connected & coaxial. Part 1: end correction (2017)
  • Report PhRxx-351x Comparisons between measurements and prediction of the acoustic radiation of a termination being connected & staggered. Part 1: end correction (2017)
  • Report PhRxx-381x Comparisons between measurements and prediction of the acoustic performance of triple expansion chamber muffers without extended tubes. Part 1: transmission loss with or without flow (2017)
  • Report PhRxx-391x Comparisons between measurements and prediction of the acoustic performance of triple expansion chamber muffers with inlet extended tube. Part 1: transmission loss with or without flow (2017)
  • Report PhRxx-401x Comparisons between measurements and prediction of the acoustic performance of triple expansion chamber muffers with outlet extended tube. Part 1: transmission loss with or without flow (2017)
  • Report PhRxx-411x Comparisons between measurements and prediction of the acoustic performance of triple expansion chamber muffers with inlet & outlet extended tubes. Part 1: transmission loss with or without flow (2017)
  • Report PhRxx-421x Comparisons between measurements and prediction of the acoustic performance of simple expansion chamber muffers with overlapping tubes. Part 1: transmission loss with or without flow (2017)
  • Report PhRxx-430x Comparisons between measurements and predictions of the parameters of a (plane) plate with an extensional damping. Part 1 effective elasticity modulus (2018)
  • Report PhRxx-440x Optimization of frequency discretization for FEM/BEM computations with constant frequency step (2018)
  • Report PhRxx-451x Simplified evaluation of Bessel Functions of first kind for Complex Arguments (2019)
  • Report PhRxx-452x Simplified evaluation of Bessel Functions of second kind for Complex Arguments (2019)
  • Report PhRxx-460x Validation of a calculation routine for solving transcendental equations involving functions with Complex Arguments (2019)
  • Report PhRxx-470x Comparisons between measurements and predictions of the properties of porous media in terms of acoustics. Part 1 influence of temperature 2020)
  • Report PhRxx-481x Comparison between measurements and predictions of the surface impedance of an absorbing lining. Part 1: plane absorber(2020)
  • Report PhRxx-482x Comparison between measurements and predictions of the surface impedance of an absorbing lining. Part 2: curved absorber (2020)
  • Report PhRxx-491x Comparisons between measurements and prediction of the acoustic radiation of a perforated plate with circular holes. Part 1: end correction(2020)
  • Report PhRxx-501x Comparisons between measurements and prediction of the acoustic radiation of a perforated plate with square holes. Part 1: end correction(2020)
  • Report PhRxx-511x Comparisons between measurements and prediction of the acoustic radiation of a perforated plate with slits. Part 1: end correction(2020)
  • Report PhRxx-521x Comparisons between measurements and prediction of the sound propagation in perforated plates with circular holes(2020)
  • Report PhRxx-541x Comparisons between measurements and prediction of the sound propagation in perforated plates with slits (2020)

Acoustics Research and Development is a major activity for ITS.