Analysis and Testing of Debris Monitoring Sensors for Aircraft Lubrication Systems

Abstract

In an aircraft engine, some pieces are describing a rotating movement. These parts are in contact with rotating and non-rotating parts through the bearings and gears. The different contact patches are lubricated with oil. During the lifetime of the engine, mechanical wear is produced between the contacts. This wear of the bearings and gears will produce some debris in the oil circuit of the engine. To ensure the effective operation of the aircraft engines, the debris monitoring sensors play a significant role. They detect and collect the debris in the oil. The analysis of the debris can give an indication of the overall health of the engine. The aim of the paper is to develop, design and model an oil test bench to simulate the oil lubrication circuit of an aircraft engine to test two different debris monitoring sensors. The methodology consists of studying the oil lubrication system of the aircraft engine. The first step is to build the oil test bench. Once the oil test bench is functional, tests are performed on the two debris monitoring sensors. A test plan is followed, three sizes of debris, like the type and sizes of debris found in the aircraft engine oil, are injected in the oil. The test parameters are the oil temperature, the oil flow rate and the mass of debris injected. Each time debris is injected, it is detected and caught by the two sensors. The test results given by the two sensors are similar to the mass debris injected into the oil circuit. The two sensors never detect the total mass of debris injected in the oil. On average, 55%–60% of the mass injected is detected and caught by the two sensors. The sensors are very efficient at detecting debris whose size corresponds to the design range parameters of the sensors, but the efficiency falls when detecting debris whose size lies outside this range.

Investigation of the Effect of Debris Position on the Detection Stability of a Magnetic Plug Sensor Based on Alternating Current Bridge

“…The researchers combined various techniques with magnetic sensors to detect the quality of the abrasive grains. These included optical sensors [ 16 , 17 ], resistive magnetic plug sensors [ 18 ], capacitive magnetic plug sensors [ 19 ], and inductive magnetic plug sensors [ 20 ]. There are two main optical detection methods: the light blockage method [ 16 ] and the imaging method [ 17 ].…”

“…Nonetheless, these techniques necessitate the implementation of intricate algorithms and high-performance hardware infrastructure. Sensors that combine an inductive coil with a permanent magnet are known for their robust resistance to interference and have been installed in aircraft engines [ 18 ]. Itomi et al [ 19 ] designed a resistive magnetic plug sensor based on an eight-rod electrode-resistive bridge uniformly arranged around the permanent magnet, with a common electrode on the base surface that establishes a connection when iron particles accumulate on one side of the permanent magnet.…”

Correlative Method for Diagnosing Gas-Turbine Tribological Systems

“…Recently, online oil debris monitoring [ 5 , 6 , 7 ] has become more and more common. It involves installing magnetic [ 8 , 9 , 10 ], capacitive [ 11 , 12 ], optical [ 13 , 14 , 15 ], or acoustic sensors [ 16 ] in the engine. These sensors can count particles or measure their diameters, but most of them are unable to identify material or detect fine wear debris.…”

Monitoring Metal Wear Particles of Friction Pairs in the Oil Systems of Gas Turbine Power Plants

“…Various methods of on-line debris monitoring in the lubrication systems of power plants are currently known. They are based on optical, capacitive, inductive, ultrasonic, resistive, X-ray, and other principles [7,[11][12][13][14][15][16][17][18]. Each of these approaches has its advantages and disadvantages.…”