Investigations of effect of phase change mass transfer rate on cavitation process with homogeneous relaxation model

Author(s):  
Zhixia He ◽  
Liang Zhang ◽  
Kaushik Saha ◽  
Sibendu Som ◽  
Lian Duan ◽  
...  
Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3757 ◽  
Author(s):  
Li ◽  
Tian ◽  
Tang

In order to obtain a high-accuracy and adaptable condensation phase change model, this paper selects the Nusselt number correlation formula that Kim proposed based on the experimental data and adjusts the Nusselt number in the bubble condensation process by calculating the phase change coefficient of the Lee model in the UDF. Through the simulation and fine-tuning of the 12 groups of operating conditions, the formula for the change of the phase change coefficient of the Lee model during the bubble condensation process is obtained. The accuracy and wide applicability of the variation formula are verified by comparison with various types of experimental data. The Lee model provides a certain reference for the numerical simulation of the bubble condensation process. The numerical simulation of the condensation process of vapor bubbles is carried out by using the formula of the phase change coefficient. The error between the simulation result of the bubble volume change and the experimental result is lower than ±15%, which basically verified the reliability of the numerical model adopted in this study. The bubble condensation process has been analyzed under various operating conditions. The simulation results show that when the bubble rises, disturbance occurs with the fluid and several tiny eddies are generated on the side of the bubble. Micro-circulation of the vapor inside the bubble accelerates the heat and mass transfer rate at the gas–liquid interface. When condensation occurs, the mass transfer rate at the interface is different and the pressure inside the bubble is higher than that around it.


2003 ◽  
Vol 68 (11) ◽  
pp. 2080-2092 ◽  
Author(s):  
Martin Keppert ◽  
Josef Krýsa ◽  
Anthony A. Wragg

The limiting diffusion current technique was used for investigation of free convective mass transfer at down-pointing up-facing isosceles triangular surfaces of varying length and inclination. As the mass transfer process, copper deposition from acidified copper(II) sulfate solution was used. It was found that the mass transfer rate increases with inclination from the vertical to the horizontal position and decreases with length of inclined surface. Correlation equations for 7 angles from 0 to 90° were found. The exponent in the ShL-RaL correlation ranged from 0.247 for the vertical case, indicating laminar flow, to 0.32 for inclinations of 60 to 90°, indicating mixed or turbulent flow. The general correlation ShL = 0.358(RaL sin θ)0.30 for the RaL sin θ range from 7 × 106 to 2 × 1011 and inclination range from 15 to 90° was obtained.


2000 ◽  
Vol 55 (7) ◽  
pp. 1257-1267 ◽  
Author(s):  
Tiruta-Barna Ligia ◽  
Barna Radu ◽  
Moszkowicz Pierre ◽  
Bae Hae-Ryong

RSC Advances ◽  
2016 ◽  
Vol 6 (111) ◽  
pp. 109978-109982 ◽  
Author(s):  
Young-Kee Kim ◽  
Sung-Yeob Lee ◽  
Byung-Keun Oh

In an enzyme process using a gas substrate, the enhanced gas liquid mass transfer rate of the gas substrate by methyl-functionalized mesoporous nanoparticles could improve the productivity.


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