Macromolecular Origins of Fifth Shear-Stress Harmonic in Large-Amplitude Oscillatory Shear Flow
Jbara, Layal M.
Gilbert, Peter H.
Giacomin, A. Jeffrey
MetadataShow full item record
This study examines the simplest relevant molecular model of a polymeric liquid in large-amplitude oscillatory shear (LAOS) flow: the suspension of rigid dumbbells in a Newtonian solvent. For such suspensions, the viscoelastic response of the polymeric liquid depends exclusively on the dynamics of dumbbell orientation. We have previously derived explicit analytical expressions for the shear rate amplitude and frequency dependences of the first and third harmonics of the alternating shear stress response in LAOS. Higher harmonics sculpt the shear stress, distorting it from its sinusoidal shape. In this work, we derive the polymer contribution to the shear stress response up to and including the next higher, fifth harmonic. For this, we use the fourth order term in the expansion of the orientation distribution to calculate the shear stress response. Our analysis employs the general method of Bird and Armstrong [J Chem Phys, 56, 3680 (1972)]. Our expression is the only one to have been derived from a molecular theory for a fifth harmonic. Our paper thus provides the first glimpse of the molecular origins of a shear stress harmonic higher than the third.
URI for this recordhttp://hdl.handle.net/1974/15331
Request an alternative formatIf you require this document in an alternate, accessible format, please contact the Queen's Adaptive Technology Centre
Showing items related by title, author, creator and subject.
Series Expansion for Shear Stress in Large-Amplitude Oscillatory Shear Flow From Oldroyd 8-Constant Framework Poungthong, P.; Giacomin, A. Jeffrey; Saengow, Chaimongkol; Kolitawong, Chanyut (2018-06)When polymeric liquids undergo large-amplitude oscillatory shear flow (LAOS), the shear stress responds as a Fourier series, the higher harmonics of which are caused by the fluid nonlinearity, and the first harmonic of ...
Molecular Origins of Higher Harmonics in Large-Amplitude Oscillatory Shear Flow: Shear Stress Response Gilbert, Peter H.; Giacomin, A. Jeffrey (2016-11-01)Recent work has focused on deepening our understanding of the molecular origins of the higher harmonics that arise in the shear stress response of polymeric liquids in large-amplitude oscillatory shear flow. For instance, ...
Giacomin, A. Jeffrey; Gilbert, Peter H.; Merger, Dimitri; Wilhelm, Manfred (2014-09-30)We compare the ratio of the amplitudes of the third to the first harmonic of the torque, |T3|/|T1|, measured in rotational parallel-disk flow, with the ratio of the corresponding harmonics of the shear stress, |T3|/|T1|, ...