High Pressure Rheology of Lubricants (Part 8)

<p>High pressure rheology of lubricants is important to know the lubricating states of metalworking and bearings/gears in Elasto-Hydrodynamic Lubrication (EHL) region. In the previous report, I have derived the van der Waals liquid state equation, and applied it to estimate high pressure density. In addition, for three material-specific constants of lubricants included in this equation, which are absolute zero volume V_t=0, liquid constant R_L, and compensation pressure P_R for pressure drop by liquid intermolecular force, the data of various lubricants were collected. In this report, a multiple linear regression analysis was performed with above three material-specific constants as the objective variables and the physical properties /chemical-structures of lubricants as explanatory variables, and then a multiple regression equation was created. As a result, it was clarified that for unknown lubricants, three material-specific constants (V_{t=0 mr-eq}, R_{L mr-eq} and P_{R mr-eq}) in the van der Waals liquid state equation and the high pressure density ρ_mr-eq can be estimated only by analyzing the physical properties and chemical structures using this multiple linear regression equation, without measuring high pressure densities by experiments using a high-pressure density measuring device. The details of the results will be reported.</p>