Acoustics. Determination of sound insulation performance of cabins. Laboratory and in situ measurements

2015 ◽  
Keyword(s):  
In Situ Measurements ◽  
Sound Insulation ◽  
Insulation Performance

Oceanwide Precise Determination of Sea Surface Height from In-Situ Measurements on Cargo Ships

2014 ◽  
Vol 37 (1) ◽  
pp. 77-96 ◽  
Author(s):  
Ole Roggenbuck ◽  
Jörg Reinking ◽  
Alexander Härting
Keyword(s):  
Sea Surface Height ◽  
Precise Determination ◽  
In Situ Measurements ◽  
Sea Surface

A Model for the Fast Determination of Modal Sound Transmission of Large Rectangular Opening

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Jiazhu Li ◽  
Rui Zhang ◽  
Shen Chen ◽  
Can Li ◽  
Jian Chen
Keyword(s):  
Wave Equations ◽  
Three Dimensional ◽  
Sound Transmission ◽  
Computational Effort ◽  
Sound Insulation ◽  
Fast Determination ◽  
High Frequencies ◽  
Higher Order Modes ◽  
Insulation Performance

Abstract The existence of openings affects the sound insulation performance of structures significantly. The determination of sound transmission through large rectangular openings is often time-consuming, because of the large number of modes, especially if there is a need to go to high frequencies. A model is proposed and detailed based on three-dimensional wave equations, the transfer matrix method, and modal superposition. The viscous and thermal boundary layer effects have been concerned; hence, the model accuracy for narrow slits was improved. The computational effort is significantly decreased by neglecting the cross-modal sound transmission. The accuracy of this model is validated by comparing it with the existing model, the measurement, and the acoustic finite element method. The study of sound transmission behavior of higher-order modes is performed. The modal sound transmission is predicted and compared for several modes. The phenomenon that is different from that of the plane wave situation is found and discussed.

scholarly journals Laboratory and In-Situ Measurements for Thermal and Acoustic Performance of Straw Bales

2019 ◽  
Vol 11 (20) ◽  
pp. 5592 ◽  
Author(s):  
Stefano Cascone ◽  
Gianpiero Evola ◽  
Antonio Gagliano ◽  
Gaetano Sciuto ◽  
Chiara Baroetto Parisi
Keyword(s):  
Thermal Conductivity ◽  
Phase Shift ◽  
In Situ Measurements ◽  
Sound Insulation ◽  
Initial Water Content ◽  
Acoustic Performance ◽  
Thermal Transmittance ◽  
Straw Bale Walls ◽  
Straw Bale

This paper investigates the performance of timber-framed walls insulated with straw bales, and compares them with similar walls containing expanded polystyrene (EPS) instead of straw bales. First, thermal conductivity, initial water content, and density of the straw bales were experimentally measured in a laboratory set-up, and the dependence of the thermal conductivity of the dry material on temperature was described. Then, the two insulation solutions were compared by looking at their steady and periodic thermal transmittance, decrement factor, phase shift, internal areal heat capacity and surface mass. Finally, the acoustic performance of both wall typologies was analyzed by means of in situ measurements in two-story buildings built in Southern Italy. The weighted apparent sound reduction index for the partition wall between two houses and the weighted standardized level difference for the façades were assessed based on ISO Standard 16283. The results indicate that the dry straw bales have an average thermal conductivity of k = 0.0573 W/(m·K), and their density is around 80 kg/m3. In addition, straw bale walls have good steady thermal performance, but they still lack sufficient thermal inertia, as witnessed by the low phase shift and the high periodic thermal transmittance. Finally, according to the on-site measurements, the results underline that the acoustic performance of the straw bale walls is far better than the walls adopting traditional EPS insulation. Overall, the straw bales investigated are a promising natural and sustainable solution for thermal and sound insulation of buildings.

Sign in / Sign up

Export Citation Format

Share Document