CFD simulation of air effect on flow field characteristics of hydro-viscous clutch with constant speed difference

2018 ◽  
Vol 19 (2) ◽  
pp. 208
Author(s):  
Xudong Zheng ◽  
Fangwei Xie ◽  
Diancheng Wu ◽  
Xinjian Guo ◽  
Bing Zhang ◽  
...  
Keyword(s):  
Flow Field ◽  
Cfd Simulation ◽  
Power Transmission ◽  
Volume Fraction ◽  
Phase Distribution ◽  
Constant Speed ◽  
Distribution Law ◽  
Two Phase ◽  
Oil Film ◽  
Speed Difference

The purpose of this paper is to study the air effects on transmission characteristics of hydro-viscous clutch and reveal the distribution law of the flow field of the oil film. The computational-fluid-dynamics (CFD) simulation model of oil film with radial oil grooves between friction pairs is taken as the study object. Considering the air effects, the pressure field, two-phase distribution, transmission torque and temperature field of the oil film are analyzed comparatively by using the CFD technology. The results show that the presence of air changes the pressure and temperature distributions of the oil film. With increase of the absolute rotational speed, the air volume fraction increases and the radius value of the air-liquid boundary decreases under condition of constant speed difference, which makes the coverage rate of the oil film on the surface of the friction disks reduce and the transmission torque of the oil film decrease. These simulation results are attributed to the study of hydro-viscous-drive and its applications. This paper also can provide a theoretical basis for the mechanism of power transmission through oil film in the presence of air effects.

Research Analysis and Experiment Study on Flow Field of Hydrodynamic Coupling

2011 ◽  
Vol 418-420 ◽  
pp. 2006-2011
Author(s):  
Rui Zhang ◽  
Cheng Jian Sun ◽  
Yue Wang
Keyword(s):  
Flow Field ◽  
Cfd Simulation ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Internal Flow ◽  
Phase Flow ◽  
Complex Flow ◽  
Two Phase ◽  
Operation Conditions ◽  
Hydrodynamic Coupling

CFD simulation and PIV test technology provide effective solution for revealing the complex flow of hydrodynamic coupling’s internal flow field. Some articles reported that the combination of CFD simulation and PIV test can be used for analyzing the internal flow field of coupling, and such analysis focuses on one-phase flow. However, most internal flow field of coupling are gas-fluid two-phase flow under the real operation conditions. In order to reflect the gas-fluid two-phase flow of coupling objectively, CFD three-dimensional numerical simulation is conducted under two typical operation conditions. In addition, modern two-dimensional PIV technology is used to test the two-phase flow. This method of combining experiments and simulation presents the characteristics of the flow field when charging ratios are different.

Numerical Simulation of Double Inlet Cylinder Cyclone Using CFD

2013 ◽  
Vol 275-277 ◽  
pp. 558-561
Author(s):  
Xiao Ming Yuan ◽  
Hui Jun Zhao ◽  
Jing Yi Qu
Keyword(s):  
Flow Field ◽  
Volume Fraction ◽  
Separation Efficiency ◽  
Separation Performance ◽  
Two Phase ◽  
Phase Volume Fraction ◽  
Fluid Field ◽  
Cylindrical Cyclone ◽  
Discrete Phase ◽  
New Type

Designed a new type of double inlet cylindrical cyclone. For search the separation performance in a cylindrical cyclone. By use of CFD，applied the RSM turbulence model and Euler two-phase flow method and ASM which to simulate separation process and flow field within a double inlet cylindrical cyclone. Then compared with the single inlet cyclone，obtained velocity distribution. Analyzed the differences of discrete phase volume fraction between different viscosity. The results show that the new-style cyclone caught more stable fluid field and higher separation efficiency. And when the viscosity is about 0.75 kg/m•s， the separation efficiency and stability of the oil core is higher. Preliminary flow field law is shown up.

CFD Simulation of Two-Phase Flow in a Downhole Venturi Meter

2011 ◽  
Vol 130-134 ◽  
pp. 3644-3647
Author(s):  
Ding Feng ◽  
Si Huang ◽  
Yu Hui Guan ◽  
Wei Guo Ma
Keyword(s):  
Optimal Design ◽  
Pressure Drop ◽  
Flow Field ◽  
Cfd Simulation ◽  
Two Phase Flow ◽  
Flow Simulation ◽  
Phase Flow ◽  
Feed Flow Rate ◽  
Two Phase ◽  
Oil Water

This work performs an oil-water two-phase flow simulation in a downhole Venturi meter to investigate the flow field and pressure characteristics with different flow and oil-water ratios. The relation between the pressure drop and the feed flow rate in the flowmeter is investigated for its optimal design.

Analysis of flow field in Si3N4 dry granulation chamber with non-standard composite structure

2020 ◽  
pp. 1-12
Author(s):  
Zhuting Jiang ◽  
Xiang Ning ◽  
Tao Duan ◽  
Nanxing Wu ◽  
Dongling Yu
Keyword(s):  
Flow Field ◽  
Composite Structures ◽  
Flow Model ◽  
Volume Fraction ◽  
Volume Distribution ◽  
Phase Flow ◽  
Two Phase ◽  
Dry Granulation ◽  
Combined Structure ◽  
Internal Distribution

In order to improve the whirling phenomenon of Si3N4 particles in the granulation chamber, the influence of the structure of the granulation chamber on the internal distribution is explored. Euler Euler’s two-phase flow model is established. The flow field in the combined structure granulation chamber with different layout is simulated. The volume distribution and velocity field change of Si3N4 particles in the combined structure granulation chamber with different layout are analyzed. The results show that the angle between two adjacent composite structures is 20∘, 60∘, 80∘ and completely standard the Si3N4 particles with volume fraction index greater than 0.8 account for 10.2%, 11.5%, 12.5% and 6.7% of the total volume respectively. When the combined structure is completely standard, several small convolutions are found. The whirling phenomenon in the granulation chamber is improved. When the angle between two adjacent composite structures is 20∘, 60∘, 80∘ and complete standard, the proportion of qualified particles is 59%, 64%, 66% and 68%. The fluidity index is 84, 85, 87 and 88, respectively. To sum up, the combination structure of the granulation chamber is a complete standard, it is beneficial to improve the spin phenomenon of Si3N4 particles in the granulation chamber.

Influence of Jordanian zeolite on the performance of a solar still: experiments and CFD simulation studies

2016 ◽  
Vol 16 (6) ◽  
pp. 1700-1709 ◽  
Author(s):  
Yazan Taamneh
Keyword(s):  
Experimental Data ◽  
Phase Change ◽  
Cfd Simulation ◽  
Volume Fraction ◽  
Solar Still ◽  
Cfd Simulations ◽  
Two Phase ◽  
Vof Model ◽  
Computational Fluid Dynamics Cfd ◽  
Good Agreement

Computational fluid dynamics (CFD) simulations were performed for experiments carried out with two identical pyramid-shaped solar stills. One was filled with Jordanian zeolite-seawater and the second was filled with seawater only. This work is focused on CFD analysis validation with experimental data conducted using a model of phase change interaction (evaporation-condensation model) inside the solar still. A volume-of-fluid (VOF) model was used to simulate the inter phase change through evaporation-condensation between zeolite-water and water vapor inside the two solar stills. The effect of the volume fraction of the zeolite particles (0 ≤ ϕ ≤ 0.05) on the heat and distillate yield inside the solar still was investigated. Based on the CFD simulation results, the hourly quantity of freshwater showed a good agreement with the corresponding experimental data. The present study has established the utility of using the VOF two phase flow model to provide a reasonable solution to the complicated inter phase mass transfer in a solar still.

A Homogeneous Phase Change Model for Two-Phase Mechanical Seals With Three-Dimensional Face Structures

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Tao Wang ◽  
Weifeng Huang ◽  
Ying Liu ◽  
Xiangfeng Liu ◽  
Yuming Wang
Keyword(s):  
Flow Field ◽  
Phase Change ◽  
Present Model ◽  
Phase Distribution ◽  
Liquid Fraction ◽  
Change Model ◽  
Mechanical Seal ◽  
Two Phase ◽  
3D Face ◽  
Face Structure

A homogenous phase change model (HPCM) based on the mass conservation law is proposed to analyze the flow field of a two-phase mechanical seal with 3D face structures. The two-phase flow domain is governed by the simultaneous partial differential equation set containing a mass transfer governing equation for each phase with a source term derived from the Rayleigh–Plesset model and a Reynolds equation for the mixture, where the pressure and the liquid fraction are unknowns. A numerical solution is developed based on finite element method (FEM). The results from the present model are in good agreement with those from the previous two-phase mechanical seal models. A two-phase mechanical seal with wavy-tilt-dam face structure is calculated. The results indicate that the 3D face structure affects the phase distribution by altering the film pressure field. The present model is especially useful to analyze the two-phase film flow field bounded by the complex solid surfaces.

Gas Phase Distribution Effects on Heat Transfer in Upward Vertical Bubbly Channel Flows

2016 ◽  
Author(s):  
Haden Hinkle ◽  
Deify Law
Keyword(s):  
Heat Transfer ◽  
Gas Phase ◽  
Bubble Size ◽  
Single Phase ◽  
Volume Fraction ◽  
Phase Distribution ◽  
Vertical Channel ◽  
Channel Flows ◽  
Two Phase ◽  
Ansys Fluent

Two-phase (non-boiling) flows have been shown to increase heat transfer in channel flows as compared with single-phase flows. The present work explores the effects of gas phase distribution such as volume fraction and bubble size on the heat transfer in upward vertical channel flows. A two-dimensional (2D) channel flow of 10 cm wide by 100 cm high is studied numerically. Numerical simulations are performed using the commercial computational fluid dynamics (CFD) code ANSYS FLUENT. The bubble size is characterized by the Eötvös number. The volume fraction and the Eötvö number are varied parametrically to investigate their effects on Nusselt number of the two-phase flows. All simulations are compared with a single-phase flow condition.

Experimental and numerical study of air-water flow characteristics in a horizontal duct

2020 ◽  
pp. 095440622093631
Author(s):  
Mohamed H Mansour ◽  
Ali A Zahran ◽  
Lotfy H Rabie ◽  
Ibrahim M Shabaka
Keyword(s):  
Water Flow ◽  
Two Phase Flow ◽  
Volume Fraction ◽  
Phase Distribution ◽  
Electronic Device ◽  
Pipe Wall ◽  
Numerical Study ◽  
Bubble Velocity ◽  
Phase Flow ◽  
Two Phase

The horizontal bubbly two-phase flow is preferably used in various industrial applications because it provides high interfacial areas which enhance the heat and mass transfer. In the present research, the phase distribution of controlled air-water flow in a horizontal acrylic round pipe with 60 mm inside diameter (D) has been investigated experimentally and modeled numerically. The modeled differential pressure and the mixture velocity profile at a distance of 33D from the mixing section (fully developed region) are computed numerically and compared with those obtained experimentally from the two-phase flow system established and maintained at the National Institute of Standards (NIS-Egypt). Furthermore, the numerical and the experimental data have been compared with previous correlations and models. Reasonable quantitative agreement between all data is found. An electronic device based on Arduino Uno board was designed and used with careful data manipulation for measuring the slug bubble velocity. The results point out that the air volume fraction has a maximum value at the upper pipe wall as the gas bubbles tend to migrate to the upper wall. A new correlation was obtained for bubble migration length to the upper pipe wall which is very important in chemical industrial processes and other engineering application.

CFD Simulation of the Liquid-Column Flow Field of Double Contact

2012 ◽  
Vol 610-613 ◽  
pp. 1915-1919
Author(s):  
Li Jun Fang ◽  
Yan Chao Chang
Keyword(s):  
Pressure Drop ◽  
Flow Field ◽  
Gas Flow ◽  
Cfd Simulation ◽  
Equation Model ◽  
Liquid Column ◽  
Test Results ◽  
Two Phase ◽  
Simulation Calculation ◽  
Contact Liquid

It is found that the increase in the number of nozzle will lead to overall pressure drop in the tower when there is no fluid column jet and in this process RNG double equation model was used to describes gas phase turbulence, by means of simulation calculation of the gas-liquid two phase flow field in double contact liquid-column tower. In the stage of liquid column jet, with the increasing of the number of nozzle pressure drop range reduced, but phase change is more apparent, flow field distribution in the tower tends to be evenly. Through the numerical simulation of the particular condition, gas flow condition was described in conditions of different nozzle number and different liquid air ratio. Calculation is well agreed with test results, which show that the model and the algorithm has good predictive and reliability.

CFD Simulation of Two-Phase Immersion Cooling Using FC-72 Dielectric Fluid

2020 ◽  
Author(s):  
Amirreza Niazmand ◽  
Tushar Chauhan ◽  
Satyam Saini ◽  
Pardeep Shahi ◽  
Pratik Vithoba Bansode ◽  
...  
Keyword(s):  
Cfd Simulation ◽  
Volume Fraction ◽  
Rensselaer Polytechnic Institute ◽  
Bath Temperature ◽  
Maximum Temperature ◽  
Dielectric Fluid ◽  
Full Potential ◽  
Two Phase ◽  
Immersion Cooling ◽  
Over The Top

Abstract With more development in electronics system capable of having larger functional densities, power density is increasing. Immersion cooling demonstrates the highest power usage efficiency (PUE) among all cooling techniques for data centers and there is still interest in optimizing immersion cooling to use it to its full potential. The aim of this paper is to present the effect of inclination and thermal shadowing on two-phase immersion cooling using FC-72. For simulation of boiling, the RPI (Rensselaer Polytechnic Institute) wall boiling model has been used. Also, two empirical models were used for calculation of bubble departure diameter and nucleate site density. The boundary condition was assumed to be constant heat flux and the bath temperature was kept at boiling temperature of FC-72 and the container pressure is assumed to be atmospheric. this study showed that due to the thermal shadowing, boiling boundary layer can lay over the top chipset and increases vapor volume fraction over top chipsets. This ultimately causes increase in maximum temperature of second chip. The other main observation is with higher inclination angle of chip, maximum temperature on the chip decreases up to 3°C.

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