scholarly journals Theoretical Modeling, Design and Simulation of an Innovative Diverting Valve Based on Coanda Effect

Fluids ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 103
Author(s):  
Giancarlo Comes ◽  
Carlo Cravero
Keyword(s):  
Fluid Dynamics ◽  
Mathematical Model ◽  
Computational Fluid Dynamics ◽  
Additive Manufacturing ◽  
Water Flow ◽  
Coanda Effect ◽  
Geometrical Parameters ◽  
Convex Wall ◽  
Fluidic Device ◽  
Coandǎ Effect

The present work is focused on the study of an innovative fluidic device. It consists of a two-ways diverter valve able to elaborate an inlet water flow and divert it through one of the two outlets without moving parts but as a result of a fluctuation of pressure induced by two actuation ports, or channels. Such apparatus is named Attachment Bi-Stable Diverter (ABD) and is able to work with the effect of the fluid adhesion to a convex wall adjacent to it, this phenomenon is known as Coanda Effect; it generates the force responsible for the fluid attachment and the consequent deviation. The main purpose of this work is to develop a knowhow for the design and development of such particular device. A mathematical model for the ABD has been developed and used to find the relationships between the geometrical parameters and the operative conditions. A configuration has been designed, simulated with a computational fluid dynamics approach. A prototype has been printed with and additive manufacturing printer and tested in laboratory to check the effective working point of the device.

scholarly journals Evaluation of Active Heat Sinks Design under Forced Convection—Effect of Geometric and Boundary Parameters

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2041
Author(s):  
Eva C. Silva ◽  
Álvaro M. Sampaio ◽  
António J. Pontes
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Additive Manufacturing ◽  
Pressure Drop ◽  
Forced Convection ◽  
Thermal Performance ◽  
Heat Sinks ◽  
Trapezoidal Shape ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations

This study shows the performance of heat sinks (HS) with different designs under forced convection, varying geometric and boundary parameters, via computational fluid dynamics simulations. Initially, a complete and detailed analysis of the thermal performance of various conventional HS designs was taken. Afterwards, HS designs were modified following some additive manufacturing approaches. The HS performance was compared by measuring their temperatures and pressure drop after 15 s. Smaller diameters/thicknesses and larger fins/pins spacing provided better results. For fins HS, the use of radial fins, with an inverted trapezoidal shape and with larger holes was advantageous. Regarding pins HS, the best option contemplated circular pins in combination with frontal holes in their structure. Additionally, lattice HS, only possible to be produced by additive manufacturing, was also studied. Lower temperatures were obtained with a hexagon unit cell. Lastly, a comparison between the best HS in each category showed a lower thermal resistance for lattice HS. Despite the increase of at least 38% in pressure drop, a consequence of its frontal area, the temperature was 26% and 56% lower when compared to conventional pins and fins HS, respectively, and 9% and 28% lower when compared to the best pins and best fins of this study.

Computational Fluid Dynamics Modeling of Gas–Liquid Cylindrical Cyclones, Geometrical Analysis

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Juan Carlos Berrio ◽  
Eduardo Pereyra ◽  
Nicolas Ratkovich
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Cfd Modeling ◽  
Nozzle Geometry ◽  
Geometrical Parameters ◽  
Experimental Setup ◽  
Dynamics Modeling ◽  
Two Phase ◽  
Mean Square Errors

The gas–liquid cylindrical cyclone (GLCC) is a widely used alternative for gas–liquid conventional separation. Besides its maturity, the effect of some geometrical parameters over its performance is not fully understood. The main objective of this study is to use computational fluid dynamics (CFD) modeling in order to evaluate the effect of geometrical modifications in the reduction of liquid carry over (LCO) and gas carry under (GCU). Simulations for two-phase flow were carried out under zero net liquid flow, and the average liquid holdup was compared with Kanshio (Kanshio, S., 2015, “Multiphase Flow in Pipe Cyclonic Separator,” Ph.D. thesis, Cranfield University, Cranfield, UK) obtaining root-mean-square errors around 13% between CFD and experimental data. An experimental setup, in which LCO data were acquired, was built in order to validate a CFD model that includes both phases entering to the GLCC. An average discrepancy below 6% was obtained by comparing simulations with experimental data. Once the model was validated, five geometrical variables were tested with CFD. The considered variables correspond to the inlet configuration (location and inclination angle), the effect of dual inlet, and nozzle geometry (diameter and area reduction). Based on the results, the best configuration corresponds to an angle of 27 deg, inlet location 10 cm above the center, a dual inlet with 20 cm of spacing between both legs, a nozzle of 3.5 cm of diameter, and a volute inlet of 15% of pipe area. The combination of these options in the same geometry reduced LCO by 98% with respect to the original case of the experimental setup. Finally, the swirling decay was studied with CFD showing that liquid has a greater impact than the gas flowrate.

Multi-Fluid Mathematical Model for Blast Furnace and its Parallel Solution

2014 ◽  
Vol 675-677 ◽  
pp. 1463-1472
Author(s):  
Jia Le Meng ◽  
Jian Hua Shao ◽  
Ai Min Zhao
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Mathematical Model ◽  
Computational Fluid Dynamics ◽  
Blast Furnace ◽  
Furnace Operation ◽  
Blast Furnace Operation ◽  
Computing Technology ◽  
Parallel Solution ◽  
Accelerate Convergence

Developing blast furnace model is benefit to understand, control and improve blast furnace iron making process. Multi-fluid blast furnace model was established on computational fluid dynamics, reaction kinetics, transport phenomena and other theories. In the model, complicated motion and heat transfer between phases of gas, liquid and solid were considered and numerous reactions in blast furnace were simplified. Because there were so many equations in the model and there were strong coupling relationships between phases, parallel computing technology using computer group was adopted to solve the model to accelerate convergence velocity of iteration. The model can provide versatile information, it is a useful tool to simulate blast furnace operation.

scholarly journals Performance Analysis and Modeling of Microplastic Separation through Hydro Cyclones

2021 ◽  
Author(s):  
Fabio Borgia
Keyword(s):  
Fluid Dynamics ◽  
Mathematical Model ◽  
Computational Fluid Dynamics ◽  
Cfd Modeling ◽  
Separation Device ◽  
Operation Conditions ◽  
Computational Fluid Dynamics Cfd ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
The Mathematical Model

The filtering hydro cyclone is a solid–liquid separation device, generally conical in shape. The hydro cyclone allows the separation of microplastics from water, to facilitate micro-recycling. To test the capabilities of a hydro cyclone at separating microplastics from water, Rietema’s standard sizes, mathematical and computational fluid dynamics (CFD) modeling were used. The results show that, even dough the mathematical model in unreliable when considering parameters out-side standard operation conditions, hydro cyclone microplastic separation can be achieved at 98% efficiency. Particles reach the outlet on average in 1.5 s for a flow velocity of 2 m/s, and denser microplastics end up in the underflow.

scholarly journals Mathematical Model of Airflow in the Lungs of Children II: Effects of Ventilatory Parameters

2000 ◽  
Vol 3 (1) ◽  
pp. 51-62 ◽  
Author(s):  
X. Guan ◽  
R. A. Segal ◽  
M. Shearer ◽  
T. B. Martonen
Keyword(s):  
Fluid Dynamics ◽  
Mathematical Model ◽  
Computational Fluid Dynamics ◽  
Tidal Volume ◽  
Drug Distribution ◽  
Breathing Rate ◽  
Aerosol Therapy ◽  
Model Lung ◽  
Ventilatory Parameters ◽  
Child Age

In an effort to develop more effective aerosol therapy procedures, we examined airflow patterns in the lung of a child (age four years). In particular, we were concerned with how ventilatory parameters (i.e., breathing rate and tidal volume) affected the patterns of airflow around tumors. To conduct the study, a computational fluid dynamics package, FIDAP was used to define a model lung. The results of simulations show the extent to which changing ventilatory parameters can affect flow patterns in the neighborhood of the tumors as well as drug distribution throughout the lung.

Sign in / Sign up

Export Citation Format

Share Document