Mechanism Analysis of Weakening Reverse Compression Waves in Gas Wave Refrigerator

2018 ◽  
Vol 10 (6) ◽  
Author(s):  
Peiqi Liu ◽  
Kehan Wu ◽  
Sheng Liu ◽  
Wenhu Tan ◽  
Che Zhu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
High Temperature ◽  
Optimal Structure ◽  
Mechanism Analysis ◽  
Experiment Research ◽  
Compression Waves ◽  
Core Components ◽  
Practical Effect ◽  
Pressure Exchange ◽  
Further Development

Abstract Pressure oscillating tubes are core components of the gas wave refrigerator. The reverse compression waves will limit refrigeration efficiency by reheat cooling gas. The promotion from traditional rotation gas wave refrigerator with single opened pressure oscillating tubes to the streamlined pressure exchange gas wave refrigerator with double opened pressure oscillating tubes is mainly in terms of this issue. However, through weakened, reverse compression waves are still inevitable. For further development, the concept of a wave attenuator has been proposed, installed at the high-temperature (HT) port. Numerical simulation has been utilized to analyze mechanism of wave attenuator and the practical effect has been proved by experiment research. The conclusions are as follows: due to structure of wave attenuator, the intensity of reverse compression waves has been weakened; the optimal structure of wave attenuator has been obtained; the refrigeration efficiency of the refrigerator has been significantly increased because of wave attenuator in HT port.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

Community-Based Interventions to Reduce Child Maltreatment

2021 ◽  
pp. 104973152098696
Author(s):  
Camilla Kin-Ming Lo ◽  
Yuet Wing Cho
Keyword(s):  
Child Maltreatment ◽  
Hybrid Approach ◽  
Inclusion Criteria ◽  
Community Members ◽  
Protective Services ◽  
Community Based Interventions ◽  
Community Based ◽  
Community Institutions ◽  
Core Components ◽  
Further Development

Purpose: This review seeks to summarize selected literature on existing findings on the impacts of community-based interventions on the actual reduction of child maltreatment and to identify the core components of the interventions. Methods: This study systematically searched electronic databases, including PsycInfo, Medline, and Web of Science. The findings of the selected studies were summarized using narrative synthesis. Results: A total of four studies met the inclusion criteria of this study. The studies showed declines in child maltreatment incidences reported by child protective services and hospitals during the study periods. Four major components and approaches were identified among the selected interventions, including (1) the involvement of community members, (2) partnerships with community institutions, (3) multidisciplinary collaboration, and (4) responsiveness to the needs of the communities involved. Conclusions: The results of this review support the need for further development of community-based interventions using a hybrid approach.

scholarly journals Solution of AntiSeepage for Mengxi River Based on Numerical Simulation of Unsaturated Seepage

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Youjun Ji ◽  
Linzhi Zhang ◽  
Jiannan Yue
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Experiment Research ◽  
Natural Conditions ◽  
Two Phase ◽  
Ground Water Pollution ◽  
Leakage Mechanism ◽  
Analysis Experiment ◽  
Seepage Theory ◽  
Unsaturated Seepage

Lessening the leakage of surface water can reduce the waste of water resources and ground water pollution. To solve the problem that Mengxi River could not store water enduringly, geology investigation, theoretical analysis, experiment research, and numerical simulation analysis were carried out. Firstly, the seepage mathematical model was established based on unsaturated seepage theory; secondly, the experimental equipment for testing hydraulic conductivity of unsaturated soil was developed to obtain the curve of two-phase flow. The numerical simulation of leakage in natural conditions proves the previous inference and leakage mechanism of river. At last, the seepage control capacities of different impervious materials were compared by numerical simulations. According to the engineering actuality, the impervious material was selected. The impervious measure in this paper has been proved to be effectible by hydrogeological research today.

Numerical Simulation of Interior Flow in Evaporation Droplet

2014 ◽  
Author(s):  
Qingming Dong ◽  
Zhentao Wang ◽  
Yonghui Zhang ◽  
Junfeng Wang
Keyword(s):  
Numerical Simulation ◽  
High Temperature ◽  
Internal Flow ◽  
Surface Force ◽  
Droplet Surface ◽  
Force Model ◽  
Marangoni Flow ◽  
High Temperature Area ◽  
Interior Flow ◽  
Temperature Area

In this present study, the VOF (Volume of Fluid) approach is adopted to capture the interface, and CSF (Continuum Surface Force) model to calculate the surface tension, and the governing equations are founded in numerical simulation of evaporating droplets. In this work, a water droplet is assumed to be suspending in high temperature air, and the gravity of a droplet is ignored. During evaporating process of the droplet, the internal circulation flow will be induced due to the gradient of temperature at the droplet surface. The interface flows from high temperature area to low temperature area, which pulls the liquid to produce convective flow inside the droplet called as Marangoni flow. Marangoni flow makes the temperature distribution tend to uniformity, which enhances heat transfer but weakens Marangoni flow in turn. So, during droplet evaporation, the internal flow is not steady.

Sign in / Sign up

Export Citation Format

Share Document