Research on viscoelastic fluid unsteady flow model based on torque loss correction

• DOI: 10.1016/j.polymertesting.2020.106927
• Publication Date: 2020-10-24T01:43:12Z
• Authors: Bingfan Li; Gang Liu; Shiyuan Liu; Lei Chen
• Keywords: Herschel–Bulkley fluid; Oscillation (cell signaling); Generalized Newtonian fluid

To address the complexity of unsteady shear flow in initial start-up stage rheometers, a model considering torque losses motors and fixtures was developed based on true balance relationship at rotor boundary rheometer constitutive equation viscoelastic rheological model. The fluid transient established, real wall stress expression obtained. reliability verified by comparing result from analytical with numerical calculation. impact geometric dimensions test system material characteristics analyzed. results show that non-uniform velocity distribution has little effect strain response gap actual rheometer. oscillation curves obtained methods coincide completely, proving characterizing flow. For Jeffery fluid, elastic modulus G mainly affects period amplitude, parallel viscosity pots η1 amplitude attenuation speed, series clay η2 influence slope curve. greater inertia, more significant creep process. coupling between inertia viscoelasticity is essential cause oscillation. Combined mechanical rheometer, short term correction loss established. can accurately describe time curve gelled crude oil stage. this study help understand properties materials