Temperature-Dependent Viscosity Model for Silicone Oil and Its Application in Viscous Dampers

Abstract

Silicone fluids belong to the group of pseudoplastic non-Newtonian fluids with complex rheological characteristics. They are considered in basic and applied researches and in a wide range of industrial applications due to their favorable physical and thermal properties. One of their specific field of applications in the automotive industry is the working fluid of viscous torsional vibration dampers. For numerical studies in the design and development phase of this damping product, it is essential to have thorough rheological knowledge and mathematical description about the silicone oil viscosity. In the present work, adopted rheological measurement results conducted on polydimethylsiloxane manufactured by Wacker Chemie with initial viscosity of 1000 Pas (AK 1 000 000 STAB silicone oil) are processed. As a result of the parameter identification by nonlinear regression, the temperature-dependent parameter curves of the Carreau–Yasuda non-Newtonian viscosity model are generated. By implementing these parameter sets into a Computational Fluid Dynamics (CFD) software, a temperature- and shear-rate-dependent viscosity model of silicone fluid was tested, using transient flow and thermal simulations on elementary tube geometries in the size range of a real viscous torsional vibration damper’s flow channels and filling chambers. The numerical results of the finite volume method provide information about the developed flow processes, with especial care for the resulted flow pattern, shear rate, viscosity and timing.

High-power continuous-wave optical waveguiding in a silica micro/nanofibre

“…3c and Supplementary video S 3 ) shows that the droplet can be driven more than 10 times faster than those reported in previous MNF-based optomechanics systems 16 , 18 , 50 . The nonlinear power-velocity behavior (with a fitting function v o ≈ A × P in 2 + B × P in , A = 4.1×10 −4 m s −1 W −2 , B = 3.0×10 −5 m s −1 W −1 ) can be attributed to a photothermal effect, in which the viscosity of the silicone oil decreases due to the temperature rising with the increasing power, resulting in a nonlinear dependence of the velocity on waveguided power 51 . The MNF-guided high-power evanescent field can also offer non-contact optomechanical manipulation of relatively large objects in air.…”

Semi-active control of crankshaft skyhook based on magnetorheological torsional damper

“…Currently, passive vibration dampers, such as silicone oil viscous dampers (Li and Zhang 2020;Venczel et al, 2021a;Venczel et al, 2021b) and rubber dampers (Penkov 2008;Ning et al, 2013;Willenborg and Kroger 2017), are usually adopted to protect the engine camshaft and crankshaft from the possible damage caused by torsional vibrations and help to avoid the barred speed ranges. The vibration energy is converted into heat, which then dissipates from the damper's surface into the ambient air.…”

Multi-Condition Temperature Field Simulation Analysis of Magnetorheological Grease Torsional Vibration Damper

“…Venczel et al developed a two-dimensional thermal calculation program based on the finite difference method, analyzed the heat transfer process inside silicone oil dampers, and developed a temperature and shear rate-dependent viscosity model for the silicone fluid (Venczel and Veress. 2020;Venczel et al, 2021). Gordaninejad et al conducted an experimental and theoretical study of heat generation and dissipation in magnetorheological dampers, developed a theoretical model for predicting the temperature rise of magnetorheological dampers, and developed a control equation in the dimensionless form (Gordaninejad and Breese, 1999).…”