Acoustical Engineering Services

ATOA's ACOUSTICAL ENGINEERING SERVICES

Acoustics is the branch of engineering related to auditory sense and speech. Noise pollution is attributed to injuries, discomfort and fatigue in human and is a growing concern. High  quality sound without noise is desirable.  Acoustical design principles are used in Architectural Acoustics, Automobile NVH, Environmental Noise control, structural dynamics, underwater acoustics, audio devices, ultrasonics and hypersonics.  Miniaturization, Noise cancellation, acoustical metamaterials are the growth trend. ATOA provides all aspects of sound engineering simulations for minimizing noise pollution and improving the performance of acoustical products.

Acoustical Engineering Simulations Solutions

Sound wave propagation and its interaction are critical to predict the performance and to minimize the noise level and enhance the quality of sound. We provide simulation services spanning all aspects of acoustical engineering simulations in both frequency and time domain for, Virtual sound measurement, sound reduction, Soundproofing, Noise reduction and Noise Control. We provide following basic acoustical Engineering simulations,

• Architectural and Building Acoustical Simulations.

• Industrial noise and Vibration isolation and control

• Automobile Noise vibration and Harness (NVH) for interior and mufflers noise reduction

• Aero acoustics for aircraft and wind blade related noise control.

• Electro acoustics Modeling of speakers and microphone for higher sound quality

• Underwater sonar acoustics transducer  design for navigation and fisheries.

• Ultrasonic simulations for predicting the performance of Ultrasound transducer, Industrial ultrasonic cleaners, Ultrasonic cavitation, Ultrasonic Welding, Ultrasonic Nondestructive testing and Ultrasonic medical imaging is also offered.

• Simulation services for Sound Transmission Loss and Acoustic property prediction of composite material or component designs to meet, Attenuation coefficient, Sound transmission level and Acoustic Impedance through virtual anechoic room.

• Geometrical acoustics: ray approximation based simulations for high frequency acoustical device design.

• Nonlinear acoustical simulations for high power or high amplitude applications.

Multiphysics Acoustical Engineering Simulation Solutions

Our multiphysics coupled specialty include, interaction of sound waves with elastic or mechanical and electromagnetic waves for coupled Noise and Vibration, Pressure acoustics and structural interaction and Electro acoustics. Our Speciality coupled MULTIPHYSICS CAE for Acoustical Engineering includes,

• Electroacoustics, Coupled acoustical and  Electrical simulation for high quality sound reproduction system design such as microphones, loud speaker.

• Coupled acoustical and structural simulation for the interaction of sound and elastic waves.

• Coupled Flow and acoustics for sounds propagation in porous medium.

• Thermoacoustics, coupled thermal and acoustical simulations for thermal and viscous loss effects.

• Optical + Acoustical coupling for optically transparent sound insulating panels.

Emerging Acoustical Engineering

Our focus on emerging technologies related to Acoustical Engineering are,

• Acoustic metamaterials, Sonic or Acoustic crystals for novel soundproofing, focussing, concentration and acoustic wave guiding.

• Miniaturisation of acoustical system for use in mobile electronic devices.

• Multilevel acoustical modelling for broadband response and near zero sound absorption.

• Passive noise cancellation panels.

ATOA’s  New addition to  Acoustical Engineering Solutions,

• 3D Printing of Acoustical metamaterial based products.

• Acoustical Engineering design apps for sound transmission loss, STL, resonance, transmission, reflection and absorption prediction.

Acoustical Engineering spans a wide application area from architectural to automobile to industrial to consumer to defence. Wave equation for sound waves governs the compressible lossless fluid flow problems. For the special case of time-harmonic, wave equation for acoustic wave propagation reduces to an inhomogeneous Helmholtz equation.  Wave equation coupled with Navier-Stokes equation is used for solving Coupled Acoustical and flow problems such as aero and thermo acoustics. Multiphysics CAE and Acoustical metamaterials takes acoustical engineering to a new height for innovative  noise handling solutions.  

Contact ATOA for advanced  Acoustical Engineering simulation solutions at cae@atoa.com

ACOUSTICAL ENGINEERING Keywords

Sound Applications: Civil, Building Acoustics, Architectural Acoustics, Environmental, Acoustics, Highways Noise, Industrial,  Machinery, Heavy Equipment, Rotating Machinery, Transportation, Road Traffic, Aircraft, Automobile, Audio equipment's, Loudspeakers, Microphone, Hearing Aids, Musical Instruments
Instrumentation: Sensors, Medical Imaging, NDT/NDE/NDC, Navigation, Sonar, Under Water, Acoustic Microscopy

Sound Basics: Hypersound, Ultrasound, Acoustic, Infrasound, Sound Absorption, Reflection, Transmission, Propagation, Interference, Diffraction, Resonance, Reverberation, Sonic Bandgap, Noise Level, Sound Level, Linear Acoustics, Nonlinear Acoustics, Pressure Acoustics
Multiphysics: Structural + Acoustics, Vibration + Acoustics, Aeroacoustics, Bioacoustics, Electroacoustics, Thermoacoustics

Computational Acoustical Mechanics

Introduction to Acoustical Mechanics

Acoustical mechanics is the branch of engineering that deals with the study and application of sound waves and vibrations. In this domain, engineers analyze the generation, transmission, and reception of sound in various media such as air, water, and solids. Understanding acoustics is crucial for the design of systems that either generate or mitigate sound, such as speakers, microphones, soundproofing materials, and even medical devices like ultrasound machines.

The computational domain of acoustics allows engineers to model and simulate sound behaviors in complex environments, leading to more effective designs and enhanced product performance.

Use Cases in Acoustical Mechanics

Acoustical mechanics plays a significant role across a wide range of industries, including:

               Automotive Industry: Noise, Vibration, and Harshness (NVH) analysis to reduce unwanted cabin noise and improve passenger comfort.

               Consumer Electronics: Designing audio devices such as headphones, speakers, and microphones for improved sound quality.

               Architecture: Acoustic design for buildings, ensuring optimal sound propagation in theaters, concert halls, and recording studios.

               Marine Engineering: Sonar systems that use sound waves for underwater navigation, detection, and communication.

               Medical Devices: Ultrasound technology for non-invasive diagnostic and therapeutic applications.

               Aerospace Industry: Noise reduction in aircraft engines and cabin environments to ensure compliance with noise regulations and improve comfort.

Basics of Acoustical Mechanics

Acoustical mechanics deals with the generation, propagation, and reception of sound waves. Sound waves are mechanical vibrations that travel through a medium (gas, liquid, or solid) and can be characterized by their frequency, amplitude, wavelength, and speed. In acoustics, key concepts include:

·             Pressure Waves: These are the primary type of sound wave and are created by alternating regions of compression and rarefaction in the medium.

·             Frequency: Measured in Hertz (Hz), it determines the pitch of the sound. Low frequencies correspond to bass sounds, while high frequencies correspond to treble.

·             Amplitude: Determines the loudness of the sound, measured in decibels (dB).

·             Wavelength: The distance between successive compressions in a sound wave, which is inversely proportional to the frequency.

·             Speed of Sound: Varies with the medium through which the sound is traveling and is influenced by factors such as temperature and density of the medium.

Types of Acoustical Analysis

Acoustical analysis can be divided into several types based on the environment and application:

·             Environmental Acoustics: Focuses on sound propagation in open spaces, such as outdoor noise pollution control.

·             Room Acoustics: Studies how sound behaves in enclosed spaces like theaters and lecture halls, aiming to optimize sound reflection, absorption, and diffusion.

·             Structural Acoustics: Deals with how structures vibrate and radiate sound, such as in the analysis of buildings, ships, and aircraft for noise control.

·             Aeroacoustics: Examines the generation and transmission of sound due to turbulent airflow, relevant in the design of quieter aircraft engines.

·             Underwater Acoustics: Focuses on sound propagation in water, crucial for sonar systems and underwater communication.

Computational Models in Acoustical Mechanics

Computational models are essential for analyzing complex acoustic phenomena. The most widely used computational approaches include:

·             Finite Element Method (FEM): Used to model sound propagation in complex geometries, such as speaker enclosures or vehicle cabins. It discretizes the acoustic domain into small elements and solves the governing equations for each element.

·             Boundary Element Method (BEM): Suitable for modeling sound fields in unbounded or infinite domains, such as noise propagation from an aircraft or underwater sonar waves.

·             Finite Difference Time Domain (FDTD): A time-stepping method that simulates sound wave propagation by discretizing both time and space. It is particularly useful in modeling how sound waves evolve over time in a given environment.

Partial Differential Equations (PDEs) in Acoustical Mechanics

The behavior of sound waves is governed by a set of partial differential equations (PDEs) known as the wave equation. The fundamental wave equation in acoustics is derived from Newton’s second law, the conservation of mass, and the adiabatic relation between pressure and density. The wave equation can be expressed as:

∇^2 p(r,t) - (1/c^2) * ∂^2 p(r,t) / ∂t^2 = 0

Where:

  p(r,t) = field variable (e.g., pressure, potential, etc.) depending on space r and time t

  ∇^2 = Laplacian operator (spatial second derivatives)

  c = wave propagation speed

This equation describes how pressure waves propagate in a medium, forming the basis for many acoustical simulations.

Material Properties Required in Acoustical Mechanics

For effective acoustic design, the following material properties are typically required:

·             Density: The mass per unit volume of the material, which influences sound speed and impedance.

·             Sound Speed (c): Determines how quickly sound waves travel through a medium.

·             Absorption Coefficient: Measures how much sound energy is absorbed by a material, rather than being reflected or transmitted.

·             Impedance: A combination of material density and sound speed, which governs how sound waves interact at material boundaries.

Materials designed for acoustical applications must balance these properties to achieve the desired performance in specific environments.

Typical Product Performance Characteristics

In the field of acoustics, the performance of products is often evaluated based on the following criteria:

·             Sound Pressure Level (SPL): A measure of the intensity of the sound, commonly used in evaluating audio systems, noise control, and environmental noise pollution.

·             Frequency Response: Describes how well a product reproduces different frequencies, crucial for the design of speakers and microphones.

·             Transmission Loss: The ability of a material or structure to block sound, often used in the design of soundproofing materials and barriers.

·             Reverberation Time (RT60): The time it takes for sound to decay by 60 dB in a space, relevant in room acoustics design.

Summary of Acoustical Mechanics

Acoustical mechanics in the computational domain is a key field that combines the principles of sound wave propagation with advanced numerical models to solve real-world problems in various industries. By leveraging computational techniques, engineers can optimize the design of acoustical systems and materials, leading to innovations that enhance product performance, reduce noise pollution, and improve user experiences across diverse applications.