Elastohydrodynamic performance of unexcited electro-rheological fluids

Exploratory test results arc presented for a series of mixtures of unexcited electrorheological (ER) fluids under elastohydrodynamic lubrication (ehl) conditions These were obtained from direct observation of film formation in an optical interferometric apparatus. Results are presented as photographs of the fluid film and plots of film thickness versus speed for a range of ER fluid solid fractions Adequate film formation is limited by the tendency of the solid particles to evade the contact region. At very low contact speeds particles enter the ehl contact and generate a fluid film. At higher speeds the particulates do not become entrained in the contact; the film formation is then determined by the viscosity of the base fluid.