Droplet phase change model and its application in wave-type vanes of steam generator

2018 ◽  
Vol 111 ◽  
pp. 176-187 ◽  
Author(s):  
Fulong Zhao ◽  
Chenru Zhao ◽  
Hanliang Bo
Keyword(s):  
Phase Change ◽  
Steam Generator ◽  
Change Model ◽  
Wave Type ◽  
Droplet Phase

Critical Conditions for Secondary Droplets Generated by Droplets Colliding Walls With Different Angles

2020 ◽  
Author(s):  
Yikai Wu ◽  
Wenxuan Ju ◽  
Yusheng Liu ◽  
Fulong Zhao ◽  
Sichao Tan
Keyword(s):  
Phase Change ◽  
Separation Efficiency ◽  
Three Dimensional ◽  
Gravity Separation ◽  
Critical Conditions ◽  
Vapor Flow ◽  
Change Model ◽  
Water Separation ◽  
Critical Separation ◽  
Droplet Phase

Abstract The single droplet phase change model during motion is developed based on the phenomena description and mechanism comprehension, which including the droplet phase change model as well as the droplet motion model. Then, the calculation of the droplet phase change characteristics during moving in the uniform flow in the gravity separation space is conducted. The results show that when the droplet are evaporating during its moving, the radius will decrease continuously and it will be carried more easily by the steam vapor, which will lead to the larger separation radii of the droplets and the reduced the gravity separation efficiency. In addition, this paper shows the three-dimensional map for the critical separation over the pressure difference and the steam vapor flow velocity, which can contribute to forecast the influence of the droplet phase change on the separation characteristics. The results can be applied in the design of the steam-water separation plants.

Numerical Simulation of Melting in Metal Foam/Paraffin Composite Phase Change Material Using a Physically More Reasonable Macroscale Model

2019 ◽  
Author(s):  
Yuanpeng Yao ◽  
Huiying Wu
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Metal Foam ◽  
Phase Interface ◽  
Change Model ◽  
Composite Phase Change Material ◽  
Convection Dominated ◽  
Change Material ◽  
Change Problem

Abstract In this work, a macroscale model for melting phase change of metal foam/paraffin composite phase change material (MFPC) is developed by employing the enthalpy-porosity method and volume averaging technique. Both cases of varied and unvaried paraffin density during phase change are investigated in the model, and diffusion dominated interstitial heat exchange between paraffin and metal foam is considered along with the convection dominated interstitial heat transfer. The visualization experiments on melting phase change of copper foam/paraffin composite are carried out to validate the developed phase change model. It is found that with consideration of varied density of paraffin, the developed model can effectively solve the real melting problem of MFPC when metal foam is initially filled with solid paraffin. If the Boussinesq approximation is employed (i.e., unvaried paraffin density is considered during phase change), the model is more appropriate for the phase change problem on condition that metal foam can just be filled with liquid paraffin in the end of the melting process. Hence according to different treatments of paraffin density, the application of the phase change model needs to consider the influence of real paraffin filling condition of MFPC. The phase change model considering diffusion dominated interstitial heat transfer between stationary paraffin and metal foam can more accurately capture the solid-liquid phase interface positions as compared with the model only considering the convection dominated interstitial heat transfer. The present study can provide guidance for physically more reasonable simulation of the practical phase change problem of MFPC.

A Volume of Fluid Phase Change Model on Adaptive Octree Grids

2011 ◽  
Vol 8 (3) ◽  
pp. 103348 ◽  
Author(s):  
Mohammad W. Akhtar ◽  
Stanley J. Kleis ◽  
N. Prabhu ◽  
N. Kobasko ◽  
S. W. Dean
Keyword(s):  
Phase Change ◽  
Fluid Phase ◽  
Volume Of Fluid ◽  
Change Model
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