From data centers and industrial machinery to automotive and aerospace and defense (A&D), engineers are prioritizing noise and vibration performance to meet safety standards, align with consumer expectations, and improve user experience.
Regardless of the industry or application, noise and vibration challenges involve common physics, including electromagnetic forces, fluid dynamics, mechanical defects, and structural assembly. These diverse factors include acoustic and vibration phenomena ranging from magnetic forces and turbulence to mechanical imbalances and joint issues. Addressing these factors effectively requires multiphysics solutions.
By adopting multiphysics simulation solutions from Ansys, part of Synopsys, engineers can analyze, detect, and prevent noise and vibration issues across physics domains. These insights enable improved product quality from sound and safety to user experience, while increasing product lifespan.
Take a Multiphysics Approach
Elements of physics do not happen singularly or in isolation. Electromagnetic, fluid, structural, and thermal forces interact simultaneously and affect each other. Multiphysics simulation brings different physics solvers together into a single computational framework so engineers can accurately model physics behavior across an entire system at the same time.
Let’s look at how simulation can help detect electromagnetically induced vibration and noise issues in an electric machine. Engineers can calculate these forces, simulate forced structural vibrations via harmonic response, and evaluate structural noise emissions by analyzing equivalent radiated power (ERP) or performing full harmonic acoustics calculations.
In a typical workflow you can convert tangential forces (which produce torque) and radial forces (which cause noise and vibration) from the time domain to the frequency domain with a fast Fourier transform (FFT) algorithm using the Ansys Maxwell advanced electromagnetic field solver or Ansys Motor-CAD dedicated electric motor design tool for multiphysics simulation. Next, you can map these transformed forces into a structural modal analysis model in Ansys Mechanical structural finite element analysis software to identify vibration and acoustic response.
By integrating multiphysics simulation, engineers can detect electromagnetic-driven noise and vibration issues for an electric machine.
In addition, with Maxwell software’s optimetrics built-in analysis and optimization module, engineers can automatically test and calculate how an electric machine performs across a wide range of operating speeds, without having to set up each test manually.
Fluid-driven noise can broadly be classified as pure aeroacoustics, which means the noise source and path are both in the fluid domain. For example, air is both the source and transmission path of the acoustic energy for a fan. Conversely, aero-vibro-acoustics happen when a fluid source excites a solid structure, which then radiates noise. For example, water sloshing inside a centrifugal pump vibrates the pump’s walls, which causes the outer surface to radiate noise into the surrounding air.
To analyze noise and vibration behavior of a centrifugal pump, you can use computational fluid dynamics (CFD) tools in Ansys Fluent fluid simulation software to convert transient fluid pressure into frequency-domain excitations, then export that data to a structural model using a CFD general notation system (.cgns) file. You can also capture the reaction forces and moments at the bearing interfaces from the impeller’s multibody dynamics and apply both the fluid and bearing excitations to a harmonic response analysis. This helps identify excited vibration modes and evaluate the acoustic energy radiated by structural panels.
Using computational fluid dynamics (CFD) and other multiphysics simulation solutions, engineers can analyze the noise, vibration, and aero-vibro-acoustics of a centrifugal pump.
On the mechanical side, kinematics describes how objects move by tracking their position, speed, and acceleration. Using the example of an electric powertrain, kinematic-driven vibration and acoustic simulation predicts equipment noise and vibration behavior by analyzing time-domain data of electromagnetic and gear train forces with multibody dynamics tools, such as Ansys Motion multibody dynamics simulation software.
This approach evaluates transmission errors caused by torque and misalignment to study housing vibration and the impact of gearbox defects like pitting or cracked teeth during varying operational speeds.
Multiphysics simulation, including electromagnetic analyses and multibody dynamics, can help engineers predict kinematic-driven noise and vibration issues in electric powertrains.
Consider How Sound is Perceived
At the path level, one of the most crucial factors influencing noise and vibration behavior is material property, especially damping, which is a material's ability to dissipate mechanical energy, usually by converting vibrations into heat.
To control vibration and airborne noise, engineers must accurately model how materials behave under different conditions. Vibration-control components like rubber mounts change their properties based on temperature and frequency, requiring advanced simulations and real-world test data to predict accurately. Once vibration turns into airborne noise, acoustic materials like foams and liners are used to absorb it, though blocking low-frequency noise remains a difficult design challenge. Ultimately, analyzing the effects of material thickness, placement, and airflow is essential for reducing noise in spaces like heating, ventilation, and air conditioning (HVAC) systems and engine compartments.
In addition to the physical mechanics of sound, such as vibration, absorption, and frequency, engineers study psychoacoustics to understand how humans perceive product sound quality beyond traditional acoustic measurements. After energy travels from the source and through the path it reaches the receiver, which is us as human beings.
Psychoacoustic analysis helps engineers optimize sound quality and perceived product noise beyond conventional sound pressure level metrics. Using Mechanical software’s built-in Sound Insights module, engineers can calculate specific psychoacoustic indicators, such as tonality for electrical motors or roughness for modulated sounds, which enables them to optimize designs for improved consumer perception rather than just lower sound pressure levels. Engineers can also export these simulation results into Ansys Sound post-processing sound design software then automate acoustic post-processing or customize a Python workflow using the PyAnsys Sound tool.
By simulating psychoacoustics, engineers can calculate specific indicators, such as tonality, which enables them to optimize designs for improved consumer perception rather than just lower volume.
Studying psychoacoustics, as well as the multiphysics behind it, helps engineers design products that meet noise-level standards. Standards and regulatory bodies, such as the Occupational Safety and Health Administration (OSHA), International Organization for Standardization (ISO), and Air-Conditioning, Heating, and Refrigeration Institute (AHRI), define acceptable noise limits, but do not provide design solutions. Therefore, acoustic and vibration performance targets should be incorporated early into the design cycle rather than validated at the end. By introducing simulation early on, engineers can accurately predict noise and vibration behavior, balance performance tradeoffs, and prevent costly, late-stage redesigns.
Improve Noise And Vibration Performance With Simulation
Improving noise and vibration performance requires a holistic, system-level approach that considers the interaction between the source, path, and receiver, while prioritizing human perception metrics like tonality and loudness over mere sound pressure level. By addressing these design challenges early with multiphysics simulation, engineers can shift the focus from simply reducing noise to engineering how a product is experienced.
Ansys is dedicated to advancing industrial processes and equipment with innovative solutions and helping engineers manage noise and vibration with multiphysics simulation analyses. To learn more, watch the on-demand webinar, Engineering Quiet Products: From Structural Vibration to Aeroacoustics Noise.
Just for you. We have some additional resources you may enjoy.
TAKE A LOOK
