4D multi-kHz time-resolved laser-induced incandescence for comprehensive soot characterization in unsteady flames

Müller M, Vassilyev M, Cai W, Huber F, Will S (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Book Volume: 65

Pages Range: 6915-6924

Journal Issue: 20

DOI: 10.1364/AO.603424

Abstract

Optical diagnostics that can capture the multi-dimensional and multi-parameter evolution of complex, dynamic systems are crucial for advancing our understanding of transient physical and chemical processes. A prime example is the formation of soot in unsteady combustion, where such diagnostics are central to validating predictive models. Yet to date, these investigations are mostly limited to pointwise (0D) or imaging (2D) measurements; rarely do they cover a third dimension. For turbulent and generally unsteady combustion processes, however, the fourth (temporal) dimension is crucial to resolve and track the evolution of the flow field and soot development. With our experimental approach, we extend the simultaneous diagnostics of the three essential soot characteristics—particle size, soot volume fraction, and temperature—to 4D. To that end, we couple laser-induced incandescence (LII) and two-color pyrometry (2CP) to simultaneously measure the soot particle temperature, soot volume fraction, and primary particle size in a high-speed tomographic manner. The 4D resolution is achieved by employing a high-speed laser and detection equipment in combination with an imaging fiber bundle for tomographic reconstruction. Example results in a weakly turbulent diffusion flame show that the flame is well resolved for all three investigated quantities of interest, and a spatiotemporal tracking of local flame features is now possible. Besides the measurement of soot evolution, a wide range of further applications in the field of combustion science is accessible.

Authors with CRIS profile

Involved external institutions

Shanghai Jiao Tong University / 上海交通大学 China (CN)

How to cite

APA:

Müller, M., Vassilyev, M., Cai, W., Huber, F., & Will, S. (2026). 4D multi-kHz time-resolved laser-induced incandescence for comprehensive soot characterization in unsteady flames. Applied Optics, 65(20), 6915-6924. https://doi.org/10.1364/AO.603424

MLA:

Müller, Marcel, et al. "4D multi-kHz time-resolved laser-induced incandescence for comprehensive soot characterization in unsteady flames." Applied Optics 65.20 (2026): 6915-6924.

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