Effect of Shear Rate and Temperature on Rheological Properties of Vegetable Based Oil

Petroleum oil has been the raw material for over 90% of hydraulic fluid. Limitations of this base material in the aspect of non-renewable, not environmental friendly and its sustainability in the future have prompted a search for more stable and environmentally friendly alternatives. This article presents rheological aspects of hydraulic fluid derived from bio-based material when used as hydraulic fluid. Palm oil with F10 additive is found to be most shear-stable. Various empirical models such as modified Power Law, Herschel-Bulkley and Arrhenius-type-relationship are used to evaluate the rheological data. The influence of shear rate and temperature on the variation of viscosity is clearly observed but temperature has more significant influence. Interpretations of rheological models indicate that crop oils belong to pseudo-plastic category. The effect of oil degradation in the aspect of physical property on viscosity is also evaluated.