scholarly journals Turbulent transport of discharged ground water in oceanic bottom boundary layers in a water channel experiment

2020 ◽  
Author(s):  
Nils Karow ◽  
Leonie Kandler ◽  
Martin Brede ◽  
Sven Grundmann
Keyword(s):  
Velocity Field ◽  
Ground Water ◽  
Optical Measurement ◽  
Research Training ◽  
Turbulent Transport ◽  
Water Channel ◽  
Concentration Field ◽  
Measurement Technology ◽  
Sea Bed ◽  
Measurement Area

Abstract. In the context of the DFG research training Group Baltic Transcoast the scalar transport of discharged submarine groundwater and the included tracer substances will be investigated. The research focus is the mixing of ground water under the influence of waves in shallow coastal water. The waves will be generated by a Piston type wave generator and can be varied with respect to the specific wave parameters. In the water channel a permeable sea bed model is installed which allows the intrusion of a florescent tracer fluid into the measurement area. The transport of this tracer in the water column is affected by the wave motion and will be analysed using optical measurement technology. The methods used are on the one hand the Particle Image Velocimetry, to determine the velocity field in the measurement area. On the other hand, simultaneous Laser Induced Florescence will be used to obtain the concentration field. Thus, the relation between the unsteady velocity field and the mixing of the tracer can be determined quantitatively.

scholarly journals Calculation of turbulent diffusion jets under effects of gravity and moving surrounding air

2001 ◽  
Vol 23 (2) ◽  
pp. 87-94
Author(s):  
Bui Van Ga ◽  
Nhan Hong Quang ◽  
Jean Marc Vignon
Keyword(s):  
Velocity Field ◽  
Turbulent Diffusion ◽  
Concentration Field ◽  
Integral Model ◽  
System Of Equations ◽  
Kutta Method ◽  
Air Velocity ◽  
Runge Kutta Method ◽  
Jet Axis ◽  
General Conditions

The basis theory for the turbulent diffusion of jet and flame has been presented previously [1, 2]. But that one applies only in quiet surrounding air with the effects of buoyancy neglected. In the present paper, the theory is developed further by establishing an integral model for a jet in more general conditions with variable inclined angles, under effects of gravity and surrounding air velocity in any direction compared to the jet axis. The system of equations is closed by turbulence k-E model and is solved by 4th order Runge-Kutta method. In the first stage, the model is applied to predict the velocity field, the concentration field and with development of a 0.3 m diameter jet.

scholarly journals Insight of thermally stratified Jeffrey fluid flow inside porous medium subject to chemical species and melting heat transfer

2019 ◽  
Vol 11 (9) ◽  
pp. 168781401987618
Author(s):  
Mubashar Javed ◽  
Muhammad Farooq ◽  
Aisha Anjum ◽  
Shakeel Ahmad
Keyword(s):  
Heat Transfer ◽  
Velocity Field ◽  
Thermal Stratification ◽  
Heterogeneous Reaction ◽  
Concentration Field ◽  
Chemical Species ◽  
Internal Heat ◽  
Nonlinear Problems ◽  
Deborah Number ◽  
Jeffrey Fluid

This article concentrates on two-dimensional magnetohydrodynamic stagnation flow of Jeffrey liquid on a nonlinearly stretching sheet which possesses variable thickness. Simultaneous impact of melting as well as thermal stratification is specifically investigated in this study due to their tremendous involvement in plenty of natural and industrial processes. Internal heat generation and presence of chemical species are considered to ponder at heat transfer properties. Series solution has been obtained by solving the developed nonlinear problems. Physical behavior of various controlling parameters such as velocity, thermal, and concentration fields are investigated. It has been found that temperature field decays due to higher intensity of thermal stratification parameter, but thickness of thermal boundary layer boosts up. Larger Deborah number results in incremented velocity field. For uplifted wall thickness parameter, velocity field depreciates. Concentration field declines for enhanced parameters of homogeneous as well as heterogeneous reaction. Moreover, velocity is decreasing function of porosity parameter.

Application of Optical Scanning and Photogrammetry for Evaluation of Geometrical Tolerance Values

2013 ◽  
Author(s):  
Andrzej Gessner ◽  
Roman Staniek ◽  
Jakub Michałek
Keyword(s):  
Cross Sections ◽  
Optical Measurement ◽  
Measurement Techniques ◽  
Reference Method ◽  
Test Stand ◽  
Optical Methods ◽  
Test Surface ◽  
Test Plate ◽  
Optical Scanning ◽  
Measurement Area

The hereby presented research, funded by the restricted grant LIDER, NCBiR, deals, in part, with the identification of the full implementation potential of the proposed optical measurement techniques in determination of surface flatness parameters, and their comparative assessment. The test methods included the photogrammetric measurement technique (TRITOP, GOM) and the structural light scanning approach (scanner ATOS, GOM), while the CMM measurement (DEA Global Image Clima) was the reference method. The accordingly designed and assembled experimental test stand comprised 2 steel plates. The test surfaces of the plates were appropriately ground; subsequently, the entire test stand was blackened to ascertain efficient optical scanning. Furthermore, the plates were connected by means of 8 screws, thus introducing considerable distortion. A measurement area of 140 × 240 mm was defined on the plate test surface, as determined by CMM, denoting 15 measurement paths of 240 mm in length, distributed every 10 mm, and characterized by measurement point densities of 1, 5, and 20 pt/mm. The reference CMM measurements were conducted on 3 consecutive days at different times (22 measurements in total) to exclude any possible surface modifications. Subsequently, optical scanning was applied and the measurement points lying at the cross-sections of the CMM measurement paths were isolated from the obtained polygon mesh. To further apply the photogrammetric method, the test surface was labeled with markers distributed every 10 mm and coinciding with the CMM measurement paths. Comparative analysis of the flatness parameter for the selected CMM measurement and the measurement values obtained by means of the tested optical methods included: - the entire measurement area, - the sections comprising 80, 60, 50, 45, 40, 30, 20, 15, and 10 % of the entire measurement area, decreasing centrically, - the measurement sub-areas of 30 × 50 mm allotted in the corners and in the center of the test plate. The photogrammetric error of the tested parameter was established at 1.26–19.82 %, depending on the size of the measurement area. The corresponding error value, as determined by the structural light scanning technique, amounted to 0.03–4.31 %.

scholarly journals Vision-based Deformation Measurement for Pile-soil Testing

2019 ◽  
Vol 275 ◽  
pp. 03009
Author(s):  
Kun Zhou ◽  
Linhua Chen ◽  
Shanshan Yu
Keyword(s):  
Measurement Method ◽  
Optical Measurement ◽  
High Sensitivity ◽  
Steel Tube ◽  
Image Features ◽  
Deformation Measurement ◽  
Measurement Technology ◽  
Full Field ◽  
Progressive Development ◽  
Point Tracking

Image measurement technology has been widely used in monitoring the deformation of the soil field around the pile with its advantages of no damage, no contact, full-field measurement, no added quality and high sensitivity. But there are few researches on image-based bearing deformation measurement of the pile. Through an indoor pile-soil semi-model test, the rigid body displacement and load-bearing deformation of a new type of prefabricated steel tube pile foundation under horizontal load was measured based on image features. In this study, the concept of optical extensometer is first applied to the measurement of local average strain of a non-uniform deformed structure. Based on an improved feature point tracking algorithm SURF-BRISK, non-contact measurement of tiny strain of pile body is realized. In addition, based on DIC technology, this study also obtained the progressive development of displacement field of soil around pile. The above work fully reflects the non-contact convenience and full-field richness of the optical measurement method compared with the traditional measurement method.

scholarly journals Remote and Feedback Control of the Flap Angle in a Wind Tunnel Test Model by Optical Measurement

Aerospace ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 11
Author(s):  
Kazuhisa Chiba ◽  
Tatsuro Komatsu ◽  
Hiroyuki Kato ◽  
Kazuyuki Nakakita
Keyword(s):  
Feedback Control ◽  
Wind Tunnel ◽  
Optical Measurement ◽  
Wind Tunnel Test ◽  
Measurement Technology ◽  
Test Model ◽  
Measurement Equipment ◽  
Feedback Control System ◽  
Aerodynamic Coefficients ◽  
Japan Aerospace Exploration Agency

We have developed a remote and precise feedback control system using optical measurement technology to alter the angle of a flap, which is part of a wind tunnel test model, automatically and to earn the aerodynamic data efficiently. To rectify the wasteful circumstance that Japan Aerospace Exploration Agency (JAXA)’s low-turbulence wind tunnel stops ventilation every time to switch model configurations, we repaired hardware for remote operation and generated software for feedback control. As a result, we have accomplished a system that dramatically advances the efficiency of wind tunnel tests. Moreover, the system was able to consider the deformation of the model through optical measurement; the system controlled flap angles with errors less than the minimum resolution of optical measurement equipment. Consequently, we successfully grasped the nonlinearity of three aerodynamic coefficients C L , C D , and C M p that was impossible so far.

Effects of Heat and Mass Transfer on Peristaltic Flow of Carreau Fluid in a Vertical Annulus

2010 ◽  
Vol 65 (10) ◽  
pp. 781-792 ◽  
Author(s):  
Sohail Nadeem ◽  
Noreen Sher Akbar
Keyword(s):  
Mass Transfer ◽  
Velocity Field ◽  
Shooting Method ◽  
Numerical Solutions ◽  
Concentration Field ◽  
Peristaltic Flow ◽  
Frame Of Reference ◽  
Carreau Fluid ◽  
Long Wavelength ◽  
Vertical Annulus

This article is devoted to the study of peristaltic transport of a Carreau fluid in a vertical annulus under the consideration of long wavelength. The flow is investigated in a wave frame of reference moving with the velocity of the wave. Exact solutions have been evaluated for temperature and concentration field, while approximated analytical and numerical solutions are found for the velocity field using (i) the perturbation method and (ii) the shooting method. The effects of various emerging parameters are investigated graphically.

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