caa a22 4500 60546684X CHVBK 20210128100309.0 cr unu---uuuuu 210128e20151201xx s 000 0 eng 10.1007/s00397-015-0881-8 doi (NATIONALLICENCE)springer-10.1007/s00397-015-0881-8 Rheology of a dilute viscoelastic suspension of spheroids in unconfined shear flow [Elektronische Daten] [Gaetano D'Avino, Francesco Greco, Pier Maffettone] The rheology of a dilute viscoelastic suspension of spheroids subjected to unconfined shear flow is studied by numerical simulations. To highlight the effect of the suspending fluid rheology, two viscoelastic constitutive equations, i.e., the Giesekus and the Phan-Thien-Tanner models, have been selected. Simulations are performed for a spheroid with two aspect ratios (4 and 8). The spherical particle case is also investigated for comparison. The Deborah number D e is varied between 0 and 4. The particle contribution to the viscosity is weakly affected by the particle shape and orientation. In contrast, spheroids oriented with major axis out of the vorticity direction significantly reduce the particle contribution to the first and second normal stress difference. The maximum reduction is found in the flow-alignment regime. Simulations of the transient dynamics of the suspension show that the initial distribution of the particle orientation has a remarkable influence on the evolution of the stress coefficients. The time needed to obtain steady-state rheological properties is at least one order of magnitude higher than the fluid characteristic time. Springer-Verlag Berlin Heidelberg, 2015 Spheroid nationallicence Rheology nationallicence Viscoelasticity nationallicence Numerical simulations nationallicence Dilute suspension nationallicence D'Avino Gaetano Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, P.le Tecchio 80, 80125, Napoli, Italy aut Greco Francesco Istituto di Ricerche sulla Combustione, Consiglio Nazionale delle Ricerche, P.le Tecchio 80, 80125, Napoli, Italy aut Maffettone Pier Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, P.le Tecchio 80, 80125, Napoli, Italy aut Rheologica Acta Springer Berlin Heidelberg 54/11-12(2015-12-01), 915-928 0035-4511 54:11-12<915 2015 54 397 https://doi.org/10.1007/s00397-015-0881-8 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00397-015-0881-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- D'Avino Gaetano Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, P.le Tecchio 80, 80125, Napoli, Italy aut NATIONALLICENCE 700 1- Greco Francesco Istituto di Ricerche sulla Combustione, Consiglio Nazionale delle Ricerche, P.le Tecchio 80, 80125, Napoli, Italy aut NATIONALLICENCE 700 1- Maffettone Pier Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, P.le Tecchio 80, 80125, Napoli, Italy aut NATIONALLICENCE 773 0- Rheologica Acta Springer Berlin Heidelberg 54/11-12(2015-12-01), 915-928 0035-4511 54:11-12<915 2015 54 397