Project Simulations Test Thickener and VI Improver Mechanisms in Fluids

The fluid power research projects coming out of the Center for Compact and Efficient Fluid Power (CCEFP) have continued to progress, and all ten of the newly funded projects were presented at the CCEFP Industry-University Summit in April 2017. The Simulation, Rheology, and Efficiency of Polymer Enhanced Fluids project, which is being completed by Duval Johnson, Uma Shantini Ramasamy, and Ashlie Martini at the University of California – Merced, and Mercy Cheekolu, Pawan Panwar and Paul Michael at the Milwaukee School of Engineering. The project’s goal is to bridge the gap between fundamental behavior of polymer-enhanced fluids and the performance of complex fluid power systems. Experiments have measured the effect of pressure, mean flow losses, and operating time on different fluids.

Project Premise: This project has focused on measuring how a fluid’s polymer structure affects hydraulic power transmission in pursuit of formulating more efficient hydraulic fluids. It will build upon previous research by incorporating tribometer testing, high pressure rheology studies, and molecular dynamics simulations into the research methods.

Recent Progress: The researchers have investigated the relationship between permanent viscosity loss and leakage flow. Viscoelastic properties were also investigated using an oscillatory viscometer. The functional mode of polymers was also discerned using molecular dynamics simulation techniques the researchers developed. A number of observations have come out of the experiment results:

• VI improvers reduced flow losses.
• The correlation between permanent polymer shear thinning and flow losses was weak.
• High shear rate viscosity measurements at 100°C captured both temporary and permanent viscosity loss.
• The researchers hypothesize that the combined permanent and temporary polymer shear thinning affect flow losses.

 See the presentation slides from the summit below:

Watch for project updates as the project progresses.