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Related papers: Background Oriented Schlieren in a Density Stratif…

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The background-oriented Schlieren technique has emerged as a promising method for visualizing density gradients and performing quantitative measurements. However, an inherent constraint of BOS is the compromise between spatial resolution…

Fluid Dynamics · Physics 2025-09-08 Xiang Li , Muen Gao , Weiran Wang , Jiawei Li , Chong Pan , Jinjun Wang , Yuan Xiong

Background-oriented schlieren (BOS) is a powerful technique for flow visualization. Nevertheless, the widespread dissemination of BOS is impeded by its dependence on scientific cameras, computing hardware, and dedicated analysis software.…

Human-Computer Interaction · Computer Science 2025-07-14 Diganta Rabha , Vimod Kumar , Akshay Kumar , Dinesh Saini , Manish Kumar

Quantitative measurements of fluid flow properties can be achieved by background oriented schlieren. In this paper it is shown that this depends on several factors. Image quality index is used to investigate the influence of the image…

Optics · Physics 2013-03-06 Ardian B. Gojani , Shigeru Obayashi

Background oriented schlieren (BOS) visualization technique is examined by means of optical geometry. Two most important results are the calculation of the sensitivity and spatial resolution of a BOS system, which allows for the…

Optics · Physics 2013-10-03 Ardian B. Gojani , Burim Kamishi , Shigeru Obayashi

The background-oriented schlieren (BOS) technique with the physics-based optical flow method (OF-BOS) is developed for measuring the pressure field of a laser-induced underwater shock wave. Compared to BOS with the conventional…

Fluid Dynamics · Physics 2016-12-21 Keisuke Hayasaka , Yoshiyuki Tagawa , Tianshu Liu , Masaharu Kameda

A Tomographic Background-Oriented Schlieren (TBOS) technique is developed to aid in the visualization of compressible flows. An experimental setup was devised around a sub-scale rocket nozzle, in which four cameras were set up in a circular…

Fluid Dynamics · Physics 2023-11-20 Joachim A. Bron , Woutijn J. Baars , Ferdinand F. J. Schrijer

Diffractive optical element based background oriented schlieren (BOS) is a popular technique for quantitative flow visualization. This technique relies on encoding spatial density variations of the test medium in the form of an optical…

Image and Video Processing · Electrical Eng. & Systems 2025-10-01 Viren S. Ram , Tullio de Rubeis , Dario Ambrosini , Rajshekhar Gannavarpu

We report a novel "cone-ray" model of background-oriented schlieren (BOS) imaging that accounts for depth-of-field effects. Reconstructions of the density field performed with this model are far more robust to the blur associated with a…

We build an ultra-high-speed imaging system based on the background-oriented schlieren (BOS) technique in order to capture a laser-induced underwater shock wave. This BOS technique is able to provide two-dimensional density-gradient field…

Fluid Dynamics · Physics 2015-03-20 Shota Yamamoto , Yoshiyuki Tagawa , Masaharu Kameda

We develop a framework for non-invasive volumetric indoor airflow estimation from a single viewpoint using background-oriented schlieren (BOS) measurements and physics-informed reconstruction. Our framework utilizes a light projector that…

Signal Processing · Electrical Eng. & Systems 2025-09-19 Arjun Teh , Wael H. Ali , Joshua Rapp , Hassan Mansour

In order to measure the large density-gradient fields of fluids such as underwater shock waves, we employed a fast Fourier demodulation called Fast Checkerboard Demodulation (FCD) method in Background Oriented Schlieren (BOS) technique. BOS…

Fluid Dynamics · Physics 2022-02-17 Takaaki Shimazaki , Sayaka Ichihara , Yoshiyuki Tagawa

Schlieren imaging is an optical technique to observe the flow of transparent media, such as air or water, without any particle seeding. However, conventional frame-based techniques require both high spatial and temporal resolution cameras,…

Computer Vision and Pattern Recognition · Computer Science 2024-03-05 Shintaro Shiba , Friedhelm Hamann , Yoshimitsu Aoki , Guillermo Gallego

We propose an improved density integration methodology for Background Oriented Schlieren (BOS) measurements that overcomes the noise sensitivity of the commonly used Poisson solver. The method employs a weighted least-squares (WLS)…

Fluid Dynamics · Physics 2020-12-02 Lalit Rajendran , Jiacheng Zhang , Sally Bane , Pavlos Vlachos

This study aims to overcome the problems that existing background-oriented schlieren (BOS) techniques based on computed tomography (CT-BOS) face when measuring pressure fields of laser-induced underwater shock waves. To do this, it proposes…

Fluid Dynamics · Physics 2022-11-30 Sayaka Ichihara , Takaaki Shimazaki , Yoshiyuki Tagawa

We present an uncertainty quantification methodology for density estimation from Background Oriented Schlieren (BOS) measurements, in order to provide local, instantaneous, a-posteriori uncertainty bounds on each density measurement in the…

Shock wave-droplet interactions have been receiving increasing attention due to their relevance in aviation fuel combustion and minimally invasive medical treatments, yet quantifying them experimentally remains a challenge. In this study,…

Fluid Dynamics · Physics 2026-03-24 Sayaka Ichihara , Samuele Fiorini , Yoshiyuki Tagawa , Outi Supponen

We present an image generation methodology based on ray tracing that can be used to render realistic images of Particle Image Velocimetry (PIV) and Background Oriented Schlieren (BOS) experiments in the presence of density/refractive index…

Image and Video Processing · Electrical Eng. & Systems 2019-07-24 Lalit K. Rajendran , Sally P. M. Bane , Pavlos P. Vlachos

Schlieren imaging is a powerful, non-intrusive method widely used to visualize refractive index gradients in fluid dynamics and heat transfer studies, essential in fields like aerospace engineering, combustion analysis, and supersonic flow…

Optics · Physics 2025-04-09 Shubham Saxena , Xu Wang

The paper introduces a method for studying flow dynamics using diffractive optical element based background-oriented schlieren (BOS). Our method relies on fringe demodulation using root multiple signal classification technique which…

Image and Video Processing · Electrical Eng. & Systems 2019-10-29 Jagadesh Ramaiah , Sreeprasad Ajithaprasad , Gannavarpu Rajshekhar , Dario Ambrosini

Buoyant plumes are encountered in both natural and artificial scenarios, ranging from volcanic ash clouds and wildfires to smoke from chimneys and industrial pollutant discharge to rivers and lakes. These plumes are driven by the buoyancy…

Fluid Dynamics · Physics 2026-03-31 Javed Mohd , Debopam Das
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