This is a study to assess the flow-related factors associated with real-time implementation of permittivity-based engine lubricant oil quality sensors as a step towards developing sensor-based machine learning algorithms for in situ engine health monitoring. Flow characteristics of clean oil at the chosen sensor location in the engine are visualized by adapting an external flow visualization cell. Sensor implementation on the engine follows detailed characterization on a benchtop facility emulating engine operating conditions of temperature and flow rate.
Oil quality measurements on the engine show a systematic difference from similar measurements on the benchtop facility. The presence of aeration through microbubbles in the engine oil flow, as compared with the benchtop oil flow, is hypothesized to be the reason for the bias in the electrical permittivity measurements, as these bubbles are a consistent part of the sensor’s sampling volume.
Successful implementation of oil quality sensors in engine oil flows will require systematic characterization of sensor performance under controlled aeration conditions in benchtop facilities with oil samples representing different levels of degradation. Planned additional investigations are on creating aerated flows in controlled bench top conditions to characterize sensor response using permittivity, density and viscosity measurements.
Benchtop Facility External Flow Cell on Engine Engine Test Facility
- Adam Smith and Amrutur Anilkumar, ‘Friction Factor Evaluation of Replaceable-Element and Conventional Oil Filters in a Precision Benchtop Test Facility,’ SAE Int. J. Fuels Lubr. 15(3), 2022.
- Cameron Schepner, David Schafer, and Amrutur Anilkumar, ‘In Situ Assessment of Lubricant Flow Characteristics and Oil Quality Sensor Performance – Part A: Flow Visualization’ submitted to SAE International Journal of Fuels and Lubricants, January 2023.
- Cameron Schepner, Adam Smith, and Amrutur Anilkumar, ‘In Situ Assessment of Lubricant Flow Characteristics and Oil Quality Sensor Performance – Part B: Sensor Characterization,’ submitted to SAE International Journal of Fuels and Lubricants, January 2023.