Air delivery systems in spunbond and meltblown nonwoven fabrics manufacturing involve various ducts, nozzles, blowers, compressors, valves, diffusers and sudden expansions. CFD analysis is routinely performed for most of these parts of the process. FLUENT CFD software is used for the analysis of new designs, modifying existing designs, scale-up, and troubleshooting. Fan curves can be developed for a particular impeller and casing design through parametric analysis in FLUENT. Transient airflow analysis with the details of turbulence in the flow field can be extracted. These details help to identify reasons for the stalling of diffusers, choking of nozzles, transients of air infiltration in the jets of meltblown dies, and slot attenuators in spunbond systems.

Diffuser analysis: specific charts like this can be developed for a series of diffuser geometries

Transient jet at the attenuator exit, analyzed with the FLUENT LES model.