Statistical characteristics of evaporating-freezing process of water droplet during quick depressurization

2013 ◽  
Author(s):  
Wang-Fang Du ◽  
Jian-Fu Zhao ◽  
Kai Li
Keyword(s):  
Water Droplet ◽  
Statistical Characteristics ◽  
Freezing Process

IMPROVED LUMPED-DIFFERENTIAL ANALYSIS OF THE FREEZING PROCESS IN A SUPERCOOLED WATER DROPLET

2020 ◽  
Author(s):  
Emerson Barbosa dos Anjos ◽  
Carolina Palma Naveira Cotta ◽  
Renato Machado Cotta ◽  
Igor Soares Carvalho ◽  
Manish Tiwari
Keyword(s):  
Water Droplet ◽  
Supercooled Water ◽  
Freezing Process ◽  
Differential Analysis

Numerical investigation of the impacting and freezing process of a single supercooled water droplet

2021 ◽  
Vol 33 (4) ◽  
pp. 042114
Author(s):  
Yongkui Wang ◽  
Lei Ju ◽  
Duanfeng Han ◽  
Qing Wang
Keyword(s):  
Numerical Investigation ◽  
Water Droplet ◽  
Supercooled Water ◽  
Freezing Process

scholarly journals Numeric modeling of a micro-scale differential thermal calorimeter for the purpose of cryopreservation

2017 ◽  
Author(s):  
◽  
Han Han
Keyword(s):  
Heat Flux ◽  
Temperature Distribution ◽  
Cooling Rate ◽  
Water Droplet ◽  
Biological Material ◽  
Computational Time ◽  
Freezing Process ◽  
Water Droplets ◽  
Micro Scale ◽  
Numeric Model

Cryopreservation requires biological material to be stored at temperatures well below the freezing point of water. During the process of cryopreservation, the cooling rate should be carefully chosen to avoid cell damage due to the unbalanced pressure and the solution effect. Cellular thermal analysis that determines the thermodynamics properties of a micro-scale biological material is necessary for a successful cryopreservation procedure. A micro-scale differential thermal analyzer (uDTA) was previously developed to obtain accurate thermal properties measurements of freezing cells. However, the thermal signal needs to be properly interpreted in terms of how much ice is created. Also, the future cooling profile needed to experimentally control the cooling rate needs to be developed. So a 3D numeric model was built in STAR CCM+ to study the temperature change of the water droplets while being frozen by a thermoelectric module. The heat flux profile for the boundary condition was scaled to accommodate the heat spread effect. The numeric model solutions successfully matched the temperature distribution results from the experiments. By using additional heat flux to accommodate the heat spread effect, the STAR CCM+ model generated relatively accurate results on a smaller geometry within a very short computational time. This is a big improvement compared with other high fidelity computational simulation models used to solve similar problems. After the 3D model was calibrated, the same STAR CCM+ model was used to predict the temperature distribution of different sizes of water droplets during the freezing process. This model allowed us to better understand the temperature distribution of a water droplet when the water droplet was being cooled until frozen. The modeling technique developed in this research will help establish the required cooling rates needed to control ice formation and establish thermodynamic properties of cell freezing solutions.

scholarly journals Visual study of the freezing process of a water droplet on a horizontal copper plate

2020 ◽  
Author(s):  
Zhe Zhang ◽  
Shengnan Lv ◽  
Sunil Mehendale ◽  
Lei Yan ◽  
Hui Yuan ◽  
...  
Keyword(s):  
Water Droplet ◽  
Copper Plate ◽  
Freezing Process ◽  
Visual Study

The Effects of Ambient Pressure on the Initiation of the Freezing Process for a Water Droplet on a Cold Surface

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Zheyan Jin ◽  
Yingpei Zhao ◽  
Dongyu Sui ◽  
Zhigang Yang
Keyword(s):  
Liquid Water ◽  
Water Droplet ◽  
Freezing Point ◽  
Ambient Pressure ◽  
Air Pressure ◽  
Bulk Liquid ◽  
Freezing Process ◽  
Common Belief ◽  
Cold Surface ◽  
Wide Range

This study investigated the effect of air pressure on the freezing process of a water droplet on a cold surface. A common belief is that bulk liquid water is incompressible and air pressure does not affect the freezing point of the bulk liquid water over a wide range of pressure. However, our results demonstrated that, for a water droplet on a cold surface, its freezing process started early at lower ambient pressures. Such a phenomenon can be explained by the effects of the evaporative cooling.

scholarly journals An improved lumped model for freezing of a freely suspended supercooled water droplet in air stream

2021 ◽  
Vol 130 (1) ◽  
Author(s):  
Emerson B. dos Anjos ◽  
Carolina P. Naveira-Cotta ◽  
Manish K. Tiwari ◽  
Renato M. Cotta ◽  
Igor S. Carvalho
Keyword(s):  
Water Droplet ◽  
Supercooled Water ◽  
Freezing Process ◽  
Partial Differential ◽  
Interface Position ◽  
Spherical Droplet ◽  
Differential Model ◽  
Differential Formulation ◽  
Air Stream ◽  
Freely Suspended

AbstractThis work deals with the mathematical modeling of the transient freezing process of a supercooled water droplet in a cold air stream. The aim is to develop a simple yet accurate lumped-differential model for the energy balance for a freely suspended water droplet undergoing solidification, that allows for cost effective computations of the temperatures and freezing front evolution along the whole process. The complete freezing process was described by four distinct stages, namely, supercooling, recalescence, solidification, and cooling. At each stage, the Coupled Integral Equations Approach (CIEA) is employed, which reduces the partial differential equation for the temperature distribution within the spherical droplet into coupled ordinary differential equations for dimensionless boundary temperatures and the moving interface position. The resulting lumped-differential model is expected to offer improved accuracy with respect to the classical lumped system analysis, since boundary conditions are accounted for in the averaging process through Hermite approximations for integrals. The results of the CIEA were verified using a recently advanced accurate hybrid numerical-analytical solution through the Generalized Integral Transform Technique (GITT), for the full partial differential formulation, and comparisons with numerical and experimental results from the literature. After verification and validation of the proposed model, a parametric analysis is implemented, for different conditions of airflow velocity and droplet radius, which lead to variations in the Biot numbers that allow to inspect for their influence on the accuracy of the improved lumped-differential formulation.

scholarly journals Freezing of water droplets colliding with kaolinite particles

2009 ◽  
Vol 9 (13) ◽  
pp. 4295-4300 ◽  
Author(s):  
E. A. Svensson ◽  
C. Delval ◽  
P. von Hessberg ◽  
M. S. Johnson ◽  
J. B. C. Pettersson
Keyword(s):  
Water Vapor ◽  
Relative Humidity ◽  
Water Droplet ◽  
Supercooled Water ◽  
Dust Particles ◽  
Freezing Process ◽  
Water Droplets ◽  
Electrodynamic Balance ◽  
Dry Conditions

Abstract. Contact freezing of single supercooled water droplets colliding with kaolinite dust particles has been investigated. The experiments were performed with droplets levitated in an electrodynamic balance at temperatures from 240 to 268 K. Under relatively dry conditions (when no water vapor was added) freezing was observed to occur below 249 K, while a freezing threshold of 267 K was observed when water vapor was added to the air in the chamber. The effect of relative humidity is attributed to an influence on the contact freezing process for the kaolinite-water droplet system, and it is not related to the lifetime of the droplets in the electrodynamic balance. Freezing probabilities per collision were derived assuming that collisions at the lowest temperature employed had a probability of unity. Mechanisms for contact freezing are briefly discussed.

Effect of contact angle on water droplet freezing process on a cold flat surface

2012 ◽  
Vol 40 ◽  
pp. 74-80 ◽  
Author(s):  
Lingyan Huang ◽  
Zhongliang Liu ◽  
Yaomin Liu ◽  
Yujun Gou ◽  
Li Wang
Keyword(s):  
Contact Angle ◽  
Water Droplet ◽  
Flat Surface ◽  
Freezing Process

scholarly journals Study on the Freezing Process of Water Droplet under Supercooled Conditions

1977 ◽  
Vol 43 (375) ◽  
pp. 4268-4276
Author(s):  
Michiyoshi SUZUKI ◽  
Ichiro NISHIWAKI ◽  
Mithunobu AKIYAMA
Keyword(s):  
Water Droplet ◽  
Freezing Process
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