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Suppression of ice nucleation in supercooled water under temperature gradients

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Chinese Physics B 2021年第6期30卷 657-666页

作者： Li-Ping Wang Wei-Liang Kong Pei-Xiang Bian Fu-Xin Wang Hong Liu School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China

Understanding the behaviours of ice nucleation in non-isothermal conditions is of great importance for the preparation and retention of supercooled water. Here ice nucleation in supercooled water under temperature gradients is analyzed thermodynamically based on classical nucleation theory(CNT). Given that the free energy barrier for nucleation is dependent on temperature, different from a uniform temperature usually used in CNT, an assumption of linear temperature distribution in the ice nucleus was made and taken into consideration in analysis. The critical radius of the ice nucleus for nucleation and the corresponding nucleation model in the presence of a temperature gradient were obtained. It is observed that the critical radius is determined not only by the degree of supercooling, the only dependence in CNT, but also by the temperature gradient and even the Young's contact angle. Effects of temperature gradient on the change in free energy, critical radius,nucleation barrier and nucleation rate with different contact angles and degrees of supercooling are illustrated *** results show that a temperature gradient will increase the nucleation barrier and decrease the nucleation rate, particularly in the cases of large contact angle and low degree of supercooling. In addition, there is a critical temperature gradient for a given degree of supercooling and contact angle, at the higher of which the nucleation can be suppressed completely.

关键词： supercooled water ice nucleation temperature gradient thermodynamic analysis classical nucleation theory

A molecular dynamics study on surface properties of supercooled water

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Science China(Physics,Mechanics & Astronomy) 2006年第5期49卷 616-625页

作者： Lü Yongjun & WEI Bingbo Department of Applied Physics, Northwestern Polytechnical University, Xi’an 710072, China Department of Applied Physics Northwestern Polytechnical University Xi’an China

Molecular dynamics simulations were performed to study the surface properties of water in a temperature range from 228 to 293 K by using the extended simple point charge (SPC/E) and four-site TIP4P potentials. The calculated surface tension increases with the decrease of temperature, and moreover the slopes of the surface tension-temperature curves show a weak rise below 273 K, whereas no obvious anomalies appear near 228 K, which accords with the previous experiments. Compared with the measured values, the SPC/E potential shows a good agreement, and the TIP4P potential underestimates the surface tension. The main reason for that may be the reasonable description of the surface structure of supercooled water for the SPC/E. When simulating the orientational distributions of water molecules near the surface, the SPC/E potential produces higher ordering and larger surface potentials than the TIP4P potential.

关键词： surface tension supercooled water molecular dynamics simulation.

Fragile to strong crossover and Widom line in supercooled water： A comparative study

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Frontiers of physics 2018年第1期13卷 75-83页

作者： Margherita De Marzio Gaia Camisasca Maurro Rovere Paola Gallo Dipartimento di Matematica e Fisica Universita Roma Tre Italia

The aim of this paper is to discuss the relationship between the dynamics and thermodynamics of water in the supercooled region. Reviewed case studies comprehend bulk water simulated with the SPC/E, TIP4P and TIP4P/2005 potentials, water at protein interfaces, and water in solution with electrolytes. Upon supercooling, the fragile to strong crossover in the s-relaxation of water is found to occur when the Widom line emanating from the liquid-liquid critical point is crossed. This appears to be a general characteristic of supercooled water, not depending on the applied interaction potential and/or different local environments.

关键词： molecular dynamics simulation supercooled water slow dynamics hydration water,aqueous solutions

Viscosity and stress autocorrelation function in supercooled water:A molecular dynamics study

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Viscosity and stress autocorrelation function in supercooled...

Study of Aircraft Icing Warning Algorithm Based on Millimeter Wave Radar

中国科学院地质与地球物理研究所2002学术年会

作者： KEITH REFSON Rutherford Appleton Laboratory ChiltonDidcotOxfordshire OX11 0QXUK

Following our previous study(Guo,G.-*** Zhang,Y.-G,2001,***.,99, 283) which calculates the bulk and shear viscosities of SPC/E water at 30℃and 0.999 g/cm,we performed further molecular dynamics simulations at state points of 0℃,-20℃,-40℃,and -60℃along an approximate isobar with the previous state *** and BACF(stress autocorrelation functions related to shear and bulk viscosities respectively) of high precision are obtained and compared for their similarities and *** and bulk viscosities calculated from them show an increased deviation from real water with decreasing *** correlation functions are then well fitted using a uniform two-step relaxation function including a fast oscillatory Kohlrausch law and a slow straightforward Kohlrausch *** fitting parameters of SACF and BACF are analyzed in detail and several interesting dynamic phenomena are observed, that is,1) The oscillation frequency of SACF(44～48 ps) at short time intervals agree with the stretching mode of hydrogen bonds while that of BACF(7～12 ps) with the bending mode of hydrogen bonds.2) With decreasing temperature,the slow relaxation fraction of BACF increases, while that of SACF keeps constant.3) The exponentsβin Kohlrausch laws with values greater than 1 are obtained for BACF at ambient temperatures.4) With regard to both shear and bulk viscosities, the slow relaxation time largely increases with decreasing temperature,while the fast relaxation time slightly *** phenomena are qualitatively explained and discussed in this paper.

关键词： supercooled water viscosity stress autocorrelation function molecular dynamics

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Journal of Meteorological Research 2017年第6期31卷 1034-1044页

作者： Jinhu WANG Junxiang GE Qilin ZHANG Pan FAN Ming WEI Xiangchao LI Collaborative Innovation Center on Forecast and Evaluation of MeteorologicalDisasters/Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration Nanjing University of Information Science&TechnologyNanjing 210044 Key Laboratory of Meteorological Disaster of Ministry of Education Nanjing University of Information Science&TechnologyNanjing 210044 Jiangsu Key Laboratory of Meteorological Observation and Information Processing Nanjing University of Information Science&TechnologyNanjing 210044 National Demonstration Center for Experimental Atmospheric Science and Environmental Meteorology Education Nanjing University of information Science&TechnologyNanjing 210044

In order to avoid accidents due to aircraft icing, an algorithm for identifying supercooled water was studied. Specifically, a threshold method based on millimeter wave radar, lidar, and radiosonde was used to retrieve the coverage area of supercooled water and a fuzzy logic algorithm was used to classify the observed meteorological targets. The macrophysical characteristics of supercooled water could be accurately identified by combing the threshold method with the fuzzy logic algorithm. In order to acquire microphysical characteristics of supercooled water in a mixed phase, the unimodal spectral distribution of supercooled water was extracted from a bimodal or trimodal spectral distribution of a mixed phase cloud, which was then used to retrieve the effective radius and liquid water content of supercooled water by using an empirical formula. These retrieved macro- and micro-physical characteristics of supercooled water can be used to guide aircrafts during takeoff, flight, and landing to avoid dangerous areas.

关键词： supercooled water aircraft icing millimeter wave radar threshold method fuzzy logic algorithm power spectral density

The Boson peak in confined water： An experimental investigation of the liquid-liquid phase transition hypothesis

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Frontiers of physics 2015年第5期10卷 43-49页

作者： Francesco Mallamace Carmelo Corsaro Domenico Mallamace Zhe Wang Sow-Hsin Chen Department of Nuclear Science and Engineering Massachusetts Institute of Technology Cambridge MA 02139 USA Dipartimento di Fisica e Scienze della Terra Universita di Messina I-98166 Messina Italy Consiglio Nazionale delle Ricerche-IPCF Messina I-98166 Messina Italy Dipartimento di Scienze dell'Ambiente della Sicurezza del Territorio degli Alimentie e della Salute Universit5 di Messina Viale F. Stagno d'Alcontres 31 98166 Messina Italy

The Boson peak （BP） of deeply cooled confined water is studied by using inelastic neutron scattering （INS） in a large interval of the （P, T） phase plane. By taking into account the different behavior of such a collective vibrational mode in both strong and fragile glasses as well as in glass-forming materials, we were able to determine the Widom line that characterizes supercooled bulk water within the frame of the liquid-liquid phase transition （LLPT） hypothesis. The peak frequency and width of the BP correlated with the water polymorphism of the LLPT scenario, allowing us to distinguish the ＂low-density liquid＂（LDL） and ＂high-density liquid＂（HDL） phases in deeply cooled bulk water. Moreover, the BP properties afford a further confirmation of the Widom line temperature Tw as the （P, T） locus in which the local structure of water transforms from a predominately LDL form to a predominately HDL form.

关键词： supercooled water liquid-liquid phase transition (LLPT) inelastic neutron scattering