Enhancing industrial acoustic environments through a mathematical model and 3D COMSOL acoustic simulation

Why quieter factories matter

Loud factories are more than just uncomfortable; day after day, they can slowly damage workers’ hearing, raise stress, and even reduce productivity. In many textile mills, the roar of spinning machines regularly exceeds safe limits, yet redesigning a working plant by trial and error is costly and disruptive. This paper describes a way to “rehearse” factory noise changes on a computer first, using mathematical rules and 3D simulation to rearrange machines so that sound levels drop without slowing production. The case study is a spinning factory where this digital redesign cut overall noise exposure by about three percent—enough to meaningfully reduce long-term risk when applied at scale.

The problem of noisy spinning halls

Textile spinning relies on long rows of high-speed machines that turn raw cotton into yarn. Motors, belts, and moving parts together create a constant roar that often ranges between 80 and 100 decibels, above the levels recommended for an eight-hour workday. In the Egyptian factory studied here, background sound without production was modest, but once the equipment ran, average levels in some areas climbed above 90 decibels, with the loudest zone near the carding machines. Workers often spend extended shifts in this environment, which increases the risk of noise-induced hearing loss and fatigue. Traditional protection, such as earplugs or insulation, helps but may not fully solve the problem, especially when lines are already installed and running.

Building a digital twin of the factory

To explore safer layouts without touching the real plant, the researchers first created a virtual version of the spinning hall. Using AutoCAD, they drew a 3D model of the 40-by-122-meter building and all major machines, capturing their dimensions, locations, and the areas where sound is emitted. They then imported this geometry into COMSOL Multiphysics, a scientific simulation program, and fed it detailed information about how different surfaces—brick walls, concrete floors, cotton bales, ceilings, windows, and machine bodies—absorb or reflect sound. Instead of tracking each sound wave individually, they used a diffusion-style acoustic model that treats sound energy a bit like heat spreading through a room. This approach is accurate enough for large industrial spaces but much more efficient to compute.

Letting math search for better layouts

On top of this digital twin, the team built a mathematical model that links machine placement to overall noise. It combines two key ideas: how sound from many sources adds together, and how loudness drops as distance from the source increases. The model treats the positions of machines as adjustable variables and seeks an arrangement that both keeps a reasonable workflow and reduces the combined sound pressure level. A weighting factor balances two goals: avoiding machines packed so tightly that noise remains high, but also preventing layouts that waste too much floor area. By testing different values of this factor, the authors found a middle ground where spacing is increased just enough to noticeably cut noise while keeping the production line practical.

Testing new arrangements on screen

With this optimization in place, the researchers proposed specific changes to the layout and checked each one using the 3D simulation. In the noisiest carding zone, they moved the machines farther from the nearest wall and increased the gaps between them. This reduced sound reflections and interference, bringing levels down by about 2.5 decibels. In the combing and roving areas, they rearranged rows, spread out machines, and repositioned certain units to the ends of the line, yielding nearly a 3-decibel drop. Even modest adjustments in the spinning and winding sections contributed further gains. Overall, the revised layout lowered the average sound level in the hall from 91.22 to 88.17 decibels—equivalent to roughly a 40–50 percent reduction in sound energy reaching workers during a typical shift.

What this means for workers and industry

From a worker’s point of view, a few decibels may not sound like much, but because the decibel scale is logarithmic, this change significantly reduces the strain on hearing over months and years. The study shows that before investing in new walls, enclosures, or machinery, factories can often make meaningful progress simply by rethinking where equipment sits on the floor. By pairing mathematical optimization with 3D acoustic simulation, plant designers gain a practical tool: they can predict how layout options will affect noise, filter out those that disrupt workflow, and implement the most promising arrangement with confidence. While this case focuses on a spinning mill, the same strategy can guide quieter designs in other noisy industries, helping to protect workers’ health while keeping production lines running smoothly.

Citation: Eladly, A.M., Rashwan, N., Aly, M.H. et al. Enhancing industrial acoustic environments through a mathematical model and 3D COMSOL acoustic simulation. Sci Rep 16, 10987 (2026). https://doi.org/10.1038/s41598-026-42609-6

Keywords: industrial noise, textile factories, acoustic simulation, machine layout, worker hearing protection