Smartphone schlieren and shadowgraph imaging

Settles, Gary S.

doi:10.1016/j.optlaseng.2017.07.002

Cited by 23 publications

(9 citation statements)

References 37 publications

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“…Oleh sebab itu, peneliti tertarik melakukan penelitian mengenai pengaruh bentuk turncated nozzle sudut luar dengan variasi lip thickness dengan harapan dapat diketahui prubahan luasan kestabilan api dan temperatur api. Visualisasi direct photograph dan shadow photograph akan menunjukkan gambaran nyata nyala api [12,13]. Untuk menunjang dan mempertegas hasil penelitian, selain menggunakan metode eksperimen dilakukan juga simulasi numerik (Finite Volume Method) [14,15,16].…”

Section: Pendahuluanunclassified

Pengaruh Lip Thickness Turncated Nozzle Sudut Luar terhadap Karakteristik Api Difusi Concentric Jet Flow

Huda

Widodo

Siswanto

2019

JRM

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Diffusion combustion is a daily combustion process where is often used primarily in industrial systems. An optimal burner design is needed to get more efficient combustion results. Then the shape of the burner nozzle greatly affects the turbulence between the fuel and air which forms the flow recirculation zone. The flow recirculation zone functions to produce homogeneous mixing and get a more perfect combustion. Recirculation zones are formed to disrupt flow rates, causing vortices and backflow around the end of nozzle. This research uses burner concentric jet flow. The lip thickness of the outer angles turncated nozzle are used 16 mm, 12 mm, 8 mm, 4 mm, and 0 mm length variation To obtain flame stability, the lift off and blow off limits are used with variations in air velocity. Thermocouples are used to measure the flame temperature distribution. The numerical simulations are used to reinforce this study. The results showed that the characteristics of the concentric jet flow diffusion affected by the use of the lip thickness of the outer angles turncated nozzle. The highest concentric jet flow diffusion stability is at 16 mm nozzle. The highest concentric jet flow diffusion temperature is at 12 mm nozzle. Experimental and numerical simulations show the perfect combustion on the 12 mm lip thickness nozzle. This can be seen by direct photographs of blue-dominated flames and the visualization of the temperature contour distribution which is dominated by red.

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Section: Pendahuluanunclassified

Pengaruh Lip Thickness Turncated Nozzle Sudut Luar terhadap Karakteristik Api Difusi Concentric Jet Flow

Huda

Widodo

Siswanto

2019

JRM

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“…The camera technology is quickly advancing, and the processors will become more and more powerful. For this reason, smartphones were already used for physical experiments in classes (Staacks et al 2018;Klein et al 2016), for plant identification in botanical classes (Mäder et al 2021;Wäldchen and Mäder 2018), for determining fluid properties (Chen et al 2017;Goy et al 2017;Solomon et al 2016) and even for flow visualization by Schlieren techniques (Settles 2018;Miller and Loebner 2016). The high frame rates of several hundred Hz captured by modern smartphone cameras enables their use for PIV.…”

Section: Introductionmentioning

confidence: 99%

SmartPIV: flow velocity estimates by smartphones for education and field studies

et al. 2021

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In this paper, a smartphone application is presented that was developed to lower the barrier to introduce particle image velocimetry (PIV) in lab courses. The first benefit is that a PIV system using smartphones and a continuous wave (cw-) laser is much cheaper than a conventional system and thus much more affordable for universities. The second benefit is that the design of the menus follows that of modern camera apps, which are intuitively used. Thus, the system is much less complex and costly than typical systems, and our experience showed that students have much less reservations to work with the system and to try different parameters. Last but not least the app can be applied in the field. The relative uncertainty was shown to be less than 8%, which is reasonable for quick velocity estimates. An analysis of the computational time necessary for the data evaluation showed that with the current implementation the app is capable of providing smooth live display vector fields of the flow. This might further increase the use of modern measurement techniques in industry and education. Graphic abstract

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“…The refractive index is integrated over the line of sight, and the background movement is a function of the first derivative of the density, with the x and y components separable in the image plane. The second derivative can be acquired by differentiating the data a second time during post-processing, see Settles (2018), and this method is often used for vortex visualisation by BOS to improve the image contrast, see Bauknecht et al (2016).…”

Section: Introductionmentioning

confidence: 99%

Reference-free digital shadowgraphy using a moving BOS background

et al. 2020

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A method of measuring density second derivative (shadowgraph) as a variant of background oriented schlieren (BOS) is presented. Pairs of images of a moving background with a small time difference are analysed using moving-window crosscorrelation, giving the second derivative of density in the axis of background travel. The advantage over standard BOS is that no reference image is required. In contrast to the existing "reference-free BOS" method, no double-image is produced, making the data interpretation simpler. The sum-of-correlation (ensemble correlation) method can be used on an image series, where the flow is constant over the series time, to significantly reduce the size of the cross-correlation window. The reduction in the window size and sharpening of the resulting image is similar to that achieved by optical flow, but this method is easily automatable, without knowledge of the flow, and can be used with any existing BOS analysis software.

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Smartphone schlieren and shadowgraph imaging

Cited by 23 publications

References 37 publications

Pengaruh Lip Thickness Turncated Nozzle Sudut Luar terhadap Karakteristik Api Difusi Concentric Jet Flow

Pengaruh Lip Thickness Turncated Nozzle Sudut Luar terhadap Karakteristik Api Difusi Concentric Jet Flow

SmartPIV: flow velocity estimates by smartphones for education and field studies

Reference-free digital shadowgraphy using a moving BOS background

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