Bulk Material Sound Transmission Loss Calculator

Computes transmission, absorption, and reflection for normally incident plane waves through up to 10 materials

This app is a useful educational tool for exploring sound propagation of normally incident plane waves through up to 10 different layers of bulk material (ie. panels). This calculator computes the transmission loss, power transmission coefficients, power reflection coefficients, and absorption coefficients for normally incident sound with two different boundary conditions (reflection and transmission). Users may change the length of their panels, select from various materials, or enter a custom material. Calculations are performed using the transfer matrix method with particle velocity formulation.

Current Features:

• Compute the transmission loss, power reflection coefficient, power transmission coefficient, and absorption coefficient for up to 10 different layersof bulk material
• Select from two different surrounding media (air or water) for the material assemblies
• Select from two different boundary conditions (transmission problems, where the surrounding medium encompasses both sides of the material, and reflection problems, where the particle velocity is zero at the end)
• Select from 10 different common materials including air, water, gypsum, steel, etc. Users can also enter custom materials with a known elastic modulus, Poisson ratio, and density.
• Includes thermoviscouss losses for several materials. For air, the classical absorption coefficient is utilized when turned on in the "Settings and Info" tab. For poroelastic materials, the Johnson-Champoux-Allard (JCA) method is utilized at all times
• Incorporate custom legends to denote different composite material assemblies
• Export geometries to .txt files which can be re-loaded into the app

Sources:

[1] Jiménez Noé, O. Umnova, and J.-P. Groby, Acoustic waves in periodic structures, metamaterials, and porous media: From fundamentals to industrial applications. Cham, Switzerland: Springer, 2021.

[2] D. T. Blackstock, Fundamentals of physical acoustics. New York: Wiley, 2000.

[3]P. Shravage, S. K. Jain, N. V. Karanth, and S. Raju, “Characterization of sound absorbing materials for noise control,” Journal of Acoustical Society of India, vol. 37, no. 4, pp. 147–152, Aug. 2010.