A Time-dependent Herschel-Bulkley Model for Synthetic Bronchial Mucus

Airway mucus is a complex material from a rheological point of view exhibiting a yield stress, shear-thinning, viscoplastic and thixotropic properties. Collecting real mucus being quite challenging and inducing a huge variability of the samples, mucus simulants are usually preferred to investigate in details its rheology and derive behavioral law, which are of prime importance to develop helping clearance devices and advanced numerical models. From new measurements through series of stepwise changes of shear rate, a time-dependent HerschelBulkley model is here proposed for a synthetic mucus representative of cystic fibrosis patients. The analysis is decomposed into a simplified model for steady state conditions and a full unsteady model.