TY  - JOUR
A1  - Bung, Daniel B.
T1  - Non-intrusive detection of air–water surface roughness in self-aerated chute flows
JF  - Journal of hydraulic research
Y1  - 2013
SN  - 1814-2079 (E-Journal); 0022-1686 (Print)
VL  - Vol. 51
IS  - Iss. 3
SP  - 322
EP  - 329
PB  - Taylor & Francis
CY  - London
ER  - 
TY  - JOUR
A1  - Oertel, Mario
A1  - Bung, Daniel B.
T1  - Initial stage of two-dimensional dam-break waves: laboratory versus VOF
JF  - Journal of hydraulic research
N2  - Since several decades, dam-break waves have been of main research interest. Mathematical approaches have been developed by analytical, physical and numerical models within the past 120 years. During the past 10 years, the number of research investigations has increased due to improved measurement techniques as well as significantly increased computer memories and performances. In this context, the present research deals with the initial stage of two-dimensional dam-break waves by comparing physical and numerical model results as well as analytical approaches. High-speed images and resulting particle image velocimetry calculations are thereby compared with the numerical volume-of-fluid (VOF) method, included in the commercial code FLOW-3D. Wave profiles and drag forces on placed obstacles are analysed in detail. Generally, a good agreement between the laboratory and VOF results is found.
KW  - VOF
KW  - PIV
KW  - physical model
KW  - numerical model
KW  - drag force
KW  - dam-break
Y1  - 2012
U6  - http://dx.doi.org/10.1080/00221686.2011.639981
SN  - 1814-2079 (E-Journal); 0022-1686 (Print)
VL  - 50
IS  - 1
SP  - 89
EP  - 97
PB  - Taylor & Francis
CY  - London
ER  - 
TY  - JOUR
A1  - Bung, Daniel B.
T1  - Developing flow in skimming flow regime on embankment stepped spillways
JF  - Journal of hydraulic research
Y1  - 2011
SN  - 1814-2079 (E-Journal); 0022-1686 (Print)
VL  - Vol. 49
IS  - Iss. 5
SP  - 639
EP  - 648
PB  - Taylor & Francis
CY  - London
ER  - 
TY  - JOUR
A1  - Bung, Daniel B.
A1  - Crookston, Brian M.
A1  - Valero, Daniel
T1  - Turbulent free-surface monitoring with an RGB-D sensor: the hydraulic jump case
JF  - Journal of Hydraulic Research
Y1  - 2020
U6  - http://dx.doi.org/10.1080/00221686.2020.1844810
SN  - 1814-2079
PB  - Taylor & Francis
CY  - London
ER  - 
TY  - JOUR
A1  - Bung, Daniel B.
A1  - Valero, Daniel
T1  - Optical flow estimation in aerated flows
JF  - Journal of Hydraulic Research
N2  - Optical flow estimation is known from Computer Vision where it is used to determine obstacle movements through a sequence of images following an assumption of brightness conservation. This paper presents the first study on application of the optical flow method to aerated stepped spillway flows. For this purpose, the flow is captured with a high-speed camera and illuminated with a synchronized LED light source. The flow velocities, obtained using a basic Horn–Schunck method for estimation of the optical flow coupled with an image pyramid multi-resolution approach for image filtering, compare well with data from intrusive conductivity probe measurements. Application of the Horn–Schunck method yields densely populated flow field data sets with velocity information for every pixel. It is found that the image pyramid approach has the most significant effect on the accuracy compared to other image processing techniques. However, the final results show some dependency on the pixel intensity distribution, with better accuracy found for grey values between 100 and 150.
Y1  - 2016
U6  - http://dx.doi.org/10.1080/00221686.2016.1173600
VL  - 54
IS  - 5
SP  - 575
EP  - 580
PB  - Taylor & Francis
CY  - London
ER  -