Diode laser-based standoff absorption measurement of water film thickness in retro-reflection

Pan, Rongchao; Brocksieper, Carsten; Jeffries, Jay B.; Dreier, Thomas; Schulz, Christof

doi:10.1007/s00340-016-6524-7

Cited by 8 publications

(1 citation statement)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The optical methods include optical interference [9], total internal reflection [10], laser-induced fluorescence [11], Raman scattering [12] and the absorption spectroscopy method [13,14]. Among them, the absorption spectroscopy method is advantageous due to its fast response, its ease of use, and its high sensitivity, etc [15,16]. Liquid film on a flat plate, e.g.…”

Section: Introductionmentioning

confidence: 99%

Investigation into falling film outside horizontal tube based on diode laser absorption spectroscopy

Yang¹,

Jiang²,

Guo³

et al. 2018

Meas. Sci. Technol.

View full text Add to dashboard Cite

The flow of liquid film is utilized in a wide variety of industrial processes, and an accurate investigation into film flow is essential to understand the mechanisms in the relevant processes. Here, a sensor based on diode laser absorption spectroscopy (DLAS) with an integrated optical-electrical system was developed to determine the liquid film thickness of the falling film outside a horizontal tube. The heat transfer coefficient of the liquid film was calculated using the theory of the convective heat transfer of a fluid flowing across a single tube. The imaging method was first employed to validate the measurement accuracy of the DLAS sensor; it was found that the liquid film thickness measured by the DLAS sensor and the imaging method were in good agreement, and the deviation between these two techniques was 4.57%. The relationship between liquid film thickness and heat transfer coefficient under different conditions, including spray density q (0.16/0.24/0.32 kg (m · s)−1), hot water temperature at the inlet of the tube Th (40/50/60 °C) and height of the liquid distributor hld (3/9/15 mm), were then discussed. When q increased, the heat transfer coefficient of the liquid film increased with increasing film thickness; when Th increased, the liquid film thickness remained constant while the heat transfer coefficient increased; when hld increased, the liquid film thickness decreased and the heat transfer coefficient increased.

show abstract