Laser remote sensing and photoacoustic spectrometry applied in air pollution investigation

Zelinger, Zdeněk; Střižík, Michal; Kubát, Pavel; Jaňour, Zbyněk; Berger, Pavel; Černý, Alexandr; Engst, Pavel

doi:10.1016/j.optlaseng.2004.03.005

Cited by 18 publications

(11 citation statements)

References 12 publications

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“…Profiles of the flow field physical characteristics were determined at the inlet of the geometry (see Table 2) based on experimental data from a low-speed wind tunnel for a 1:1000-scale model (see [3], [4], [5], [11]). For other model scales, the profiles were modified to keep the trend of curves.…”

Section: Rans (Reynolds-averagedmentioning

confidence: 99%

“…ANSYS Fluent 13.0 CFD (Computational Fluid Dynamics) code was used to demonstrate and visualize all problem variants (see [1], [2]). The numerical model of the pollutant plume motion created in this software had been verified by an experiment conducted in the low-speed wind tunnel in the Aerodynamic Laboratory of the Academy of Sciences of the Czech Republic in Novy Knin (see [3], [4], [5]). One of the aims of the study is also to demonstrate that physical modeling of pollutant plume motion and dispersion with severely downscaled models has its limitations that should be known and considered to avoid obtaining false results.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Physical Modeling of Gas Pollutant Motion in the Atmosphere

Zavila¹

2012

Advances in Modeling of Fluid Dynamics

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Section: Rans (Reynolds-averagedmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Physical Modeling of Gas Pollutant Motion in the Atmosphere

Zavila¹

2012

Advances in Modeling of Fluid Dynamics

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“…based on experimental data from a low-speed wind tunnel for a 1:1000-scale model (see [3], [4], [5], [6], [11]). For other model scales, the profiles were modified to keep the trend of curves.…”

Section: F Example Of Cfd Numerical Simulationmentioning

confidence: 99%

“…ANSYS Fluent 15.0 CFD (Computational Fluid Dynamics) code was used to demonstrate and visualize all problem variants (see [1], [2]). The numerical model of the pollutant plume motion created in this software was verified by an experiment conducted in the low-speed wind tunnel in the Aerodynamic Laboratory of the Academy of Sciences of the Czech Republic in Novy Knin (see [3], [4], [5]). The maximum difference between experiment data and numerical simulation data sets was one order (for more details see [6]).…”

Section: Introductionmentioning

confidence: 99%

Capacities and Limitations of Wind Tunnel Physical Experiments on Motion and Dispersion of Different Density Gas Pollutants

Zavila

Blejchař

2017

Measurement Science Review

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The article focuses on the analysis of the possibilities to model motion and dispersion of plumes of different density gas pollutants in lowspeed wind tunnels based on the application of physical similarity criteria, in this case the Froude number. The analysis of the physical nature of the modeled process by the Froude number is focused on the influence of air flow velocity, gas pollutant density and model scale. This gives an idea of limitations for this type of physical experiments in relation to the modeled real phenomena. The resulting statements and logical links are exemplified by a CFD numerical simulation of a given task calculated in ANSYS Fluent software.

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“…In previous studies (to improve the physical modelling of urban air pollution), we have developed and employed laser photoacoustic spectrometry (Zelinger et al, 2004(Zelinger et al, , 2006(Zelinger et al, , 2009. The objective of this paper is to present the design and fabrication of several home-made sensing elements of the cantilever-and-membrane type and to test and characterize their mechanical properties with the aid of the developed PAS method.…”

Section: Introductionmentioning

confidence: 99%

Silicon micro-levers and a multilayer graphene membrane studied via laser photoacoustic detection

Zelinger

Janda

Suchánek

et al. 2015

J. Sens. Sens. Syst.

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Abstract. Laser photoacoustic spectroscopy (PAS) is a method that utilizes the sensing of the pressure waves that emerge upon the absorption of radiation by absorbing species. The use of the conventional electret microphone as a pressure sensor has already reached its limit, and a new type of microphone -an optical microphone -has been suggested to increase the sensitivity of this method. The movement of a micro-lever or a membrane is sensed via a reflected beam of light, which falls onto a position-sensing detector. The use of one micro-lever as a pressure sensor in the form of a silicon cantilever has already enhanced the sensitivity of laser PAS.Herein, we test two types of home-made sensing elements -four coupled silicon micro-levers and a multilayer graphene membrane -which have the potential to enhance this sensitivity further. Graphene sheets possess outstanding electromechanical properties and demonstrate impressive sensitivity as mass detectors. Their mechanical properties make them suitable for use as micro-/nano-levers or membranes, which could function as extremely sensitive pressure sensors.Graphene sheets were prepared from multilayer graphene through the micromechanical cleavage of basal plane highly ordered pyrolytic graphite. Multilayer graphene sheets (thickness ∼ 10 2 nm) were then mounted on an additional glass window in a cuvette for PAS. The movements of the sheets induced by acoustic waves were measured using an He-Ne laser beam reflected from the sheets onto a quadrant detector. A discretely tunable CO 2 laser was used as the source of radiation energy for the laser PAS experiments. Sensitivity testing of the investigated sensing elements was performed with the aid of concentration standards and a mixing arrangement in a flow regime. The combination of sensitive microphones and micromechanical/nanomechanical elements with laser techniques offers a method for the study and development of new, reliable and highly sensitive chemical sensing systems. To our knowledge, we have produced the first demonstration of the feasibility of using four coupled silicon micro-levers and graphene membranes in an optical microphone for PAS. Although the sensitivity thus far remains inferior to that of the commercial electret microphone (with an S/N ratio that is 5 times lower), further improvement is expected to be achieved by adjusting the micro-levers and membrane elements, the photoacoustic system and the position detector.

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Laser remote sensing and photoacoustic spectrometry applied in air pollution investigation

Cited by 18 publications

References 12 publications

Physical Modeling of Gas Pollutant Motion in the Atmosphere

Physical Modeling of Gas Pollutant Motion in the Atmosphere

Capacities and Limitations of Wind Tunnel Physical Experiments on Motion and Dispersion of Different Density Gas Pollutants

Silicon micro-levers and a multilayer graphene membrane studied via laser photoacoustic detection

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