An In Situ Laser-Absorption Sensor for Crank Angle-Resolved Temperature, Pressure, and Humidity in Intake-Runner Flows

Journal Article
03-14-04-0034
ISSN: 1946-3936, e-ISSN: 1946-3944
Published March 22, 2021 by SAE International in United States
An In Situ Laser-Absorption Sensor for Crank Angle-Resolved
                    Temperature, Pressure, and Humidity in Intake-Runner Flows
Sector:
Citation: Cassady, S., Cha, D., Pinkowski, N., Strand, C. et al., "An In Situ Laser-Absorption Sensor for Crank Angle-Resolved Temperature, Pressure, and Humidity in Intake-Runner Flows," SAE Int. J. Engines 14(4):2021.
Language: English

Abstract:

Intake-runner fluid dynamics represent a vital component in the global performance of internal combustion engines, but limited diagnostics exist to characterize these gas flows. In this work, a laser absorption-based sensor was developed to measure intake-runner gas temperature, pressure, and water (H2O) mole fraction with crank-angle resolution. The sensor was designed to target two temperature-sensitive 1.8 μm absorption transitions in ambient H2O vapor. A high-resolution study of both lines was conducted, and a novel, multi-harmonic wavelength-modulation-spectroscopy (WMS) detection technique was developed to achieve sensitive measurements at 31 kS/s (once per crank angle degree at 6000 RPM). The sensor was validated in the laboratory across a range of intake-relevant conditions and subsequently demonstrated during dynamometer (dyno) testing of a single-cylinder development engine under motored and fired conditions. Beyond this demonstration, the sensor can readily be adapted for integration with a broad range of engine-intake architectures.