Hydrodynamic Performance of an Optimized Spiral Groove Bearing to Improve Plasma Skimming Effect

Plasma skimming in spiral groove bearings (SGBs) has the potential to reduce hemolysis by guiding the red blood cells to escape from the narrow ridge gap with high shear stress force, to the larger groove gap. In our previous study, we designed an optimal SGB-PS that aims to improve plasma skimming inside the bearing gaps and verified its effectiveness under whole blood conditions up to 40% hematocrit level. This study extends our work by evaluating the load-carrying capacity of the optimized SGB design. We first analyzed the load-carrying capacity numerically by calculating the hydrodynamic force based on the Reynolds equation. Then we designed and manufactured an experimental device to measure the generated hydrodynamic force under comparable conditions. Our results indicate that the hydrodynamic force generated by the SGB-PS meets the requirements for our hydrodynamically levitated rotary blood pump and aligns well with our numerical analysis. This research contributes to improving the performance of the SGB for hemolysis resistance in hydrodynamically levitated rotary blood pumps.