Liquid Property Control System for LVAD ISO 5198 Testing and Mock Circulatory Loop Simulations

Determination of performance for fluid power systems through a range of operating conditions is a crucial aspect of safety assurance. Experimental confirmation supports the computational design and verification steps taken to ensure the mechanism will perform adequately. Pumps, valves and other devices destined for hydraulic can have their performance be subject to differences in the fluid properties of the liquid. This necessitates that a range of fluid properties be examined to ensure that the operating envelope is properly characterized. Past approaches to these experiments have involved modifying the system fluid manually and only investigating a sparse set of conditions. Proposed is a liquid property unit that is able to make changes to a system fluid of a bench testing apparatus used to evaluate hydraulic devices. The chosen fluid system for the initial release of this design is a water:glycerin composition. The intent is to have a fluid chemistry that has a broad range of densities and viscosities. This unit is controlled via a user interface and is able to execute set point changes to the system fluid and maintain the total system volume desired. The design of the system, validation of its operation and use of the fluid in exemplary trials will be covered.