Pressure measurement in gas flows using laser-induced grating lifetime

Journal article

Optical diagnostics of gas-phase pressure are relatively unusual. In this work we demonstrate a novel, rapid and robust method to use laser-induced grating scattering (LIGS) to derive this property in real time. Previous pressure measurements with LIGS have employed a signal fitting methodology but this is relatively time consuming and requires specialist understanding. In this paper, we directly measure a decay lifetime from a LIGS signal and then employ a calibration surface constructed using a physics-based model to convert this value to pressure. This methodology was applied to an optically-accessible single cylinder internal combustion engine, yielding an accuracy of better than 10 % at all tested conditions above atmospheric pressure. This new approach complements the existing strength of LIGS in precisely and accurately deriving temperature with a simple analysis method, by adding pressure information with a similarly simple method.

Authors: Willman, C; Le Page, LM; Ewart, P; Williams, BAO

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Optical Society of America
• Journal: Applied Optics
• Volume: 60
• Issue: 15
• Pages: C131-C141
• Publication date: 2021-05-17
• Acceptance date: 2021-04-07
• DOI: 10.1364/AO.419973
• EISSN: 2155-3165
• ISSN: 1559-128X
• Language: English
• Keywords: FFR