scholarly journals Understanding droplet collisions through a model flow: Insights from a Burgers vortex

2019 ◽  
Vol 99 (6) ◽  
Author(s):  
Lokahith Agasthya ◽  
Jason R. Picardo ◽  
S. Ravichandran ◽  
Rama Govindarajan ◽  
Samriddhi Sankar Ray
Keyword(s):  
Droplet Collisions ◽  
Model Flow ◽  
Burgers Vortex

EULER/LAGRANGE CALCULATIONS OF TURBULENT SPRAYS: THE EFFECT OF DROPLET COLLISIONS AND COALESCENCE

2000 ◽  
Vol 10 (1) ◽  
pp. 35 ◽  
Author(s):  
M. Ruger ◽  
S. Hohmann ◽  
Martin Sommerfeld ◽  
Gangolf Kohnen
Keyword(s):  
Droplet Collisions

Karakteristik aliran dua fase pada saluran ekspansi tiba-tiba

2018 ◽  
Vol 11 (1) ◽  
pp. 7
Author(s):  
Latif Ngudi Wibawanto ◽  
Budi Santoso ◽  
Wibawa Endra Juwana
Keyword(s):  
Standard Deviation ◽  
Flow Pattern ◽  
Flow Characteristic ◽  
Homogeneous Model ◽  
Flow Equation ◽  
Pressure Recovery ◽  
Sudden Expansion ◽  
Air Velocity ◽  
Model Flow ◽  
Two Phases

This research was conducted to find out the flow characteristic of two phases through the channel with sudden expansion in the form of change of flow pattern and pressure recovery. The test was carried out with variation of superficial velocity of water 0.2-1.3 m / s and superficial air velocity of 0.2-1.9 m / s resulting in pattern of three flow patterns ie bubble, plug, and slug. The expansion channel resulted in some changes to the flow pattern that originally plugs in the upstream channel into bubble in the downstream channel and the slug becomes plug. Pressure recovery experimental results compared with the homogeneous model flow equation and Wadle correlation, both correlations have predictions with standard deviation values of 0.32 and 0.43.

Rotational separation after temporary coalescence in binary droplet collisions

2019 ◽  
Vol 4 (12) ◽  
Author(s):  
Kuo-Long Pan ◽  
Kuan-Ling Huang ◽  
Wan-Ting Hsieh ◽  
Chi-Ru Lu
Keyword(s):  
Droplet Collisions

Calculation of tunnel wall interference from wall-pressure measurements

1988 ◽  
Vol 92 (911) ◽  
pp. 36-53 ◽  
Author(s):  
P. R. Ashill ◽  
R. F. A. Keating
Keyword(s):  
Experimental Evaluation ◽  
Solid Wall ◽  
Wall Pressure ◽  
Wind Tunnels ◽  
Pressure Measurements ◽  
Complex Flows ◽  
Tunnel Wall ◽  
Model Flow ◽  
Good Agreement

Summary A method is described for calculating wall interference in solid-wall wind tunnels from measurements of static pressures at the walls. Since it does not require a simulation of the model flow, the technique is particularly suited to determining wall interference for complex flows such as those over VSTOL aircraft, helicopters and bluff shapes (e.g. cars and trucks). An experimental evaluation shows that the method gives wall-induced velocities which are in good agreement with those of existing methods in cases where these techniques are valid, and illustrates its effectiveness for inclined jets which are not readily modelled.

Testing the validity of different synthetic scenarios for flow and transport simulation in karst systems using a real case study application. 

2021 ◽  
Author(s):  
Joanna Doummar ◽  
Nidal Farran ◽  
Marwan Fahs ◽  
Benjamin Belfort ◽  
Thomas Graf
Keyword(s):  
Real Case ◽  
Richards Equation ◽  
Model Quality ◽  
Transient Model ◽  
Flow And Transport ◽  
Event Time ◽  
Model Flow ◽  
Karst Systems ◽  
The Impact

<p>Climate change and pollution are posing additional unprecedented threats to existing water resources, especially to water supply from karst aquifers in Mediterranean and semi-arid regions. A numerical model considering the most important key hydraulic parameters can forecast the impact of any given input on model quality and quantity output. In this work, we propose to model flow and transport using Comsol multiphysics in a synthetic model and to apply it to a simplified real case study (Jeita spring in Lebanon supplying water to 1.5 million inhabitants). The model geometry consists of a 5300 m long variably saturated horizontal conduit portrayed as 1) 2-D continuum and/or 2) a channel draining a porous equivalent matrix (400 m thick). Flow is simulated using the Richards Equation in both saturated and unsaturated medium. Recharge is applied vertically as both diffuse and point source in a shaft linked to the conduit. Percentages of fast infiltration rates are obtained from the analysis of event time series recorded at the spring (electrical conductivity and discharge). Flow rates at the outlet are used for transient model calibration. Mean velocities, dispersivities, and phreatic conduit diameters obtained from tracer experiments under various flow periods are used for transport validation in the channel. The aim is to test the validity of a functional simplified flow model on a complex real case and to identify based on a sensitivity analysis the key parameters that allow an optimal calibration of such a model. </p>

scholarly journals Rapid Prototyping 3D Model for PIV: Application in Human Trachea Model Flow Analysis

2021 ◽  
Vol 79 (2) ◽  
pp. 65-73
Author(s):  
Zuliazura Mohd Salleh ◽  
Kahar Osman ◽  
Mohd Fairuz Marian ◽  
Nik Normunira Mat Hassan ◽  
Rais Hanizam Madon ◽  
...  
Keyword(s):  
Rapid Prototyping ◽  
3D Model ◽  
Flow Analysis ◽  
Left Lung ◽  
Velocity Magnitude ◽  
Model Flow ◽  
Image Velocimetry ◽  
Human Trachea ◽  
Experimental Works ◽  
The Right

Experimental works for analysing flow behaviour inside human trachea has become continuous problem as the model used to study cannot imitate the real geometry of human trachea structure. As the technology develop, Rapid Prototyping (RP) become more useful in constructing the 3D model that has complexity in their geometries. RP not only offer several technologies in developing the 3D model, but also varies type of materials that can be used to manufacture the 3D model. In this study, RP technique was chosen to develop the 3D model of human trachea to do the Particle Image Velocimetry (PIV) experimental works. Material used was Vero Clear due to PIV need a model that transparent so that visualization on flow inside the model can be seen and the velocity magnitude can be capture. The geometry was adapted from 60 years old trachea patient where the images of trachea was taken by using CT-scan. MIMICS software was used to extracted the images before reconstruct the trachea into 3D model. Velocity distribution was visualized and the magnitude were taken at both left and right bronchi. From the analysis, it concluded that the distribution of airflow to the second generation of trachea was 60:40 to right and left bronchi. It follows the rules as the right bronchi need to supply more air to the right lung compared to left as the volume of right lung bigger that left lung.

scholarly journals Whole-region Tourism Greenway Network Organization Mechanism Based on Gravity Model Flow Measurement

2019 ◽  
Author(s):  
Xue Jiang ◽  
◽  
Tianyu Zhao ◽  
◽  
◽  
...  
Keyword(s):  
Gravity Model ◽  
Network Structure ◽  
Network Flow ◽  
Flow Measurement ◽  
Field Research ◽  
Minimum Cost ◽  
Small Towns ◽  
Ecological Resources ◽  
Model Flow ◽  
Structure Evaluation

The structure and organization of greenway network is the core stone of greenway planning. Generally, the relevant between point elements and line elements in the network is taken as the focus of quantitative structure evaluation. In this study, the evaluation and organization method of greenway network is based on gravity model flow measurement. Ningan city is taken as an example because of its rich tourism resources and ecological resources. The cost distance formula has been improved in the process. Network flow is allocated to each path in the gravitational model to enhance the scientific evaluation. Firstly, the existing greenway network structure is sorted out and summarized. Minimum cost path method is used to form potential greenway network structure. This structure is divided into two parts, one is based on comprehensive elements and the other is based on general elements. The existing structure and potential structure are combined to form a preliminary abstract network structure. Gravity model is used to measure and classify the traffic among abstract network nodes. Two kinds of greenway network structures are compared and analyzed. On this basis, the greenway network is optimized and verified through field research. It provides a basis for the further planning and implementation of the actual greenway network in small towns

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