Variation Of Water Density Research Articles

Electrolyte under Molybdenum Disulfide Surfaces: Molecular Insights on Structure and Dynamics of Water.

Molybdenum disulfide (MoS2) is a two-dimensional (2D) material that offers molecular transport and sieving properties and might be a potential candidate for membrane technologies for energy and environmental applications. To facilitate the separation application, understanding the structural and dynamic properties of water near the substrate-aqueous solution is essential. Employing the molecular dynamics simulation, we investigate the density, local water network at the solid-liquid interface, and water dynamics in aqueous electrolyte solutions with various chloride salts confined in MoS2 nanochannels with different pore sizes and electrolyte concentrations. Our simulation results confirm that the layering of interfacial water at the hydrophilic MoS2 surface and the water density variation depends on the nature of the ions. The simulation results imply a strong attraction of cations to the surface-liquid interfaces, whereas anions are expelled from the surface due to electrostatic interaction. An examination of the dynamical property of water reveals that the confinement effect is more pronounced on water mobility when the pore width is less than 3 nm, and the salt concentration is below 1 M, whereas the electrolyte concentration greater than 1 M, ions predominantly drive the water mobility as compared to confinement one. These simulation results enhance experimental observations and provide molecular insights into the local ordering mechanism that can be crucial in controlling water dynamics in nanofiltration applications.

Experimental and numerical study of ice storage and melting process of external melting ice coil

Ice storage air conditioning technology could achieve “peak cut” by storing ice during the valley period, melting ice during the peak period to achieve the role of peak load regulation. At the same time, it can promote consumption of renewable energy. This study deals with the experimental and numerical analysis of the solidification and melting processes of coiled ice storage. From the experimental observation, it was observed that the outer surface of the lower side of the coil was the first to form an ice layer. Then the outer surface of the upper side begins to form an ice layer, and the growth rate of the ice layer is faster than that of the lower side. The average growth rates of the ice layer on the upper and lower side are 0.112 mm/min and 0.079 mm/min, respectively. The density variation of water and natural convection were considered in this analysis. The numerical simulation results well match the phenomena and results of experimental research. The influence of different directions of cooling water inlet on the melting rate was also compared in this paper. Under the same initial conditions and boundary conditions, the melting process in the Mode 1 (along the coil) cools down faster; The ice melting process in Mode 2 (perpendicular to the coil) can provide more stable cooling, and the cooling duration is 130 s longer than that in Mode 1.

Water Density Variations of the Aral Sea from GRACE and GRACE-FO Monthly Solutions

The Gravity Recovery and Climate Experiment (GRACE) and its successor, the GRACE Follow-On (GRACE-FO) gravity satellite missions, have been providing monthly gravity field solutions for almost 20 years, enabling a unique opportunity to monitor large-scale mass variation processes. The gravity anomaly time series for the Aral Sea region has been obtained for the period of April 2002 to January 2022. The method of determining the gravity anomaly time series from GRACE and GRACE-FO monthly solutions has been improved by considering the mass variations of the Caspian Sea. The gravity anomaly time series was then compared to water mass changes determined by considering variations in the salinity and temperature of seawater. Nevertheless, the tests suggest that improvements in correlation with such information might occur, although the relevance of the improvement should not be overestimated. All in all, it can be demonstrated that salinity changes relevantly influence the gravity field; however, the signal is too weak to inversely obtain information from satellite-borne gravity observations on salinity variations.

Effects of variable thermophysical properties of water on the heat extraction of an enhanced geothermal system: A numerical case study

The variation of water thermophysical properties in deep high-temperature enhanced geothermal systems (EGS) is dramatic, which seriously affects the thermal performance of the system. While most previous researches focus on the variation of water density and viscosity with temperature in the reservoir, conversely the pressure effect and other water thermophysical properties are ignored. In this paper, a fully coupled wellbore-reservoir model is presented to explore the influences of the water thermophysical properties varied with temperature and pressure on the system's thermal performance. The model is validated against the 2D single-fracture model analytical solution and field data. The influence of different engineering methods (open-hole length, production pressure) on the system's thermal performance is explored according to the fluid flow and heat transfer mechanisms and thermophysical property analysis. Results show that the pressure difference decreases by 17.66 MPa when the open hole length increase from 20 m to 60 m. Increasing the production pressure would increase the system pressure loss and decreases the system thermal power due to the reduction of water heat capacity. These results provide significant references for the optimization design of the EGS.

Dynamics of Submersion of a «Diving Buoy» with Account of Hull Compression and Depth-Wise Variation of Water Density

The paper employs a simplified approach to modeling of dynamics of submersion of a «diving buoy» subject to a depth-wise water density gradient and experiencing compression of the hull due to action of pressure. The latter effect is accounted for through use of well-known boiler formulae of structural mechanics allowing to analyze behavior of hulls made of different materials. Operation of a piston type buoyancy engine is modeled both for a hypothetical case of instantaneous change of buoyancy and for more practical case of finite buoyancy variation. As the analysis includes both acceleration/deceleration and constant speed modes of motion it enables to evaluate full time of submersion to a design depth. Calculated are the vertical position and speed of the vehicle versus time. Due to the fact that during submersion the growth of density results in deceleration and hull compression causes acceleration, the equilibrium condition is formulated which can be seen as hanging mode in which the buoy performs damped oscillations around a depth of hanging with a frequency depending on rates of density and compression. It is shown that to provide constant speed for a general case of density variation one has to secure a corresponding volume variation of the vehicle or a corresponding increment/decrement of differential buoyancy. At the end of the paper estimates are presented showing how much additional buoyancy should be carried on board to keep constant speed of submersion and how much power is needed for corresponding buoyancy control for a given density profile.

Sensitivity analysis of control parameters errors and current parameters to motion accuracy of underwater glider using Sobol’ method

Control parameters errors and current can weaken the motion accuracy of underwater gliders, which will obstruct the achievement of high accuracy exploration missions. To improve the glider motion accuracy more pertinently, it is necessary to identify the key factors that affect the glider motion accuracy. To resolve the above problem, we employ Sobol’ method to analyze the sensitivity of control parameters errors and current parameters to the glider motion accuracy. The control parameters errors include the net buoyancy adjustment amount error, the movable mass block translation amount error and the movable mass block rotation amount error. The current parameters include the current intensity, action depth and direction. First, the dynamic model of an underwater glider is established, and this model considers the effects of hull deformation, water density variation and current simultaneously. Then the dynamic model is validated by experimental data. After the evaluation parameter of motion accuracy is given, the glide motion accuracy is preliminarily analyzed, and then the sensitivity analysis is carried out. In this paper, we calculate the sensitivity coefficients by Monte Carlo method. To reconcile calculation efficiency with calculation accuracy, a convergence rule is proposed to reduce the number of sample points that are used for calculating sensitivity coefficients as much as possible. Besides, based on simulation results of dynamic model, the surrogate models are established to participate in the calculation of sensitivity coefficients, which can improve analysis efficiency further. For two typical motion modes, analysis results identify the key factors affecting the glider motion accuracy and illustrate the form of their effect on the glider motion accuracy. This research may be valuable for the achievement of the glider precision operation.

Development and Diversity of Bacterial Biofilms in Response to Internal Tides, a Case Study off the Coast of Kuwait

Information pertaining to changes in abundance and composition of microbial communities on offshore platforms in relation to changes in environmental conditions due to internal tides are scarce. In this study, artificial substrata were deployed at two locations on a gently sloping seabed off the coast of Kuwait. The abiotic factors at the two sites were recorded spatially and temporally using time-series measurements and continuous turbulence profiling for 13 days. Results showed variations in water density between the upper and deeper waters with the pycnocline undulating between 6 and 15 m depth at both locations. In the water layer beneath the pycnocline, significant current shear due to the internal tides led to higher turbidity coupled with lower dissolved oxygen (DO) and chlorophyll a concentration. The microbiological data showed a significant decrease in the biofilm total biomass, bacterial counts and phototrophic biomass with increase in depth at both locations. The 16S rRNA amplicon sequence non-metric multidimensional (NMDS) scaling analysis revealed that biofouling bacterial communities affected by depth with Alphaproteobacteriaand Bacteroidetes members dominated upper and deeper water at both locations. The based-ordination analysis revealed that biofouling bacterial communities at 3 m were different than at 15 m, with a percentage of shared Operational taxonomic units (OTUs) ≤64% between locations and between depths. Despite the limitations of the study, the power of the employed system is demonstrated in the results that shed light on the significance of prevailing environmental conditions associated with internal tides in shaping the biofilm community in subtropical offshore water systems.

Characterizing flow pattern and salinity using the 3D MIKE 3 model: Urmia Lake case study

In this study, MIKE 3 model was used to simulate flow pattern and salinity distribution in Urmia Lake. About two decades ago, a causeway was constructed in the lake. The causeway has a 1.25-km opening and divides the lake into northern and southern basins. To perform the simulation, different influential variables such as the discharge of inflow rivers, wind speed, variation in water density, bed roughness, air temperature, relative humidity, cloud coverage, and heat flux through water surface were taken into account. Using the available water level data, salinity, and current velocity, the numerical model was calibrated and validated. Results revealed that the northern part of the lake was saltier due to the negligible entrance of fresh water into the northern part as well as the construction of causeway which restricts water exchange between the northern and southern parts of the lake. Results also showed that density-driven currents are dominant and that the fresher surface water layer in the southern part moves north and circulates counterclockwise in the northern portion of the lake, increasing water salinity and density. This water then moves to deeper layers and circulates back to the southern part.

Trends of Steric Sea Level Oscillations in the North Atlantic

We consider trends of sea level steric oscillations in the North Atlantic in 2003–2015 using two independent approaches. The first method is based on the multidisciplinary application of altimetry (AVISO) and gravimetry (GRACE mission) data. The second method is based on the integral assessment of steric oscillations using variations in the fluid volume caused by variations in water density: the calculations are carried out using the SODA, EN4, and ARMOR reanalysis data. It is shown that the application of the combined altimetry and GRACE data result in overestimated values of steric oscillations and their trends. This is related to the fact that the GRACE observations show the variations in the ocean mass; hence the sea level variations are presented in a relative coordinate system which is not the geocentric system. This system does not take into account the effects of the elastic deformation of the ocean bottom and the corresponding redistribution of the water volumes. It is shown that the maximum bias of these estimates and the errors in determining the steric oscillations and their trends based on the first method is characteristic of regions located near Greenland. This is caused by the contribution of the negative trend component to the GRACE data. If the estimates are made in regions remote from Greenland coasts, the trend component in the GRACE measurements is insignificantly manifested and the trends in the steric oscillations calculated using the method that jointly uses the AVISO and GRACE data are similar to the trends in the sea level variations based on the altimetry data. The trends of the steric oscillations of the sea level calculated from the reanalysis data are similar in the spatial distribution between both calculations and also similar to the trends in the sea level variations based on the altimetry data.

ОЦЕНКА ВЛИЯНИЯ ИЗМЕНЕНИЯ ПЛОТНОСТИ ТЕПЛОНОСИТЕЛЯ НА ТОЧНОСТЬ РАСЧЕТА ПОТВЭЛЬНОГО ЭНЕРГОВЫДЕЛЕНИЯ ВВЭР

This paper presents the verification results of SAPFIR_95&RC_micro program that is intended for fine-grid three-dimensional pin-by-pin calculation of power in VVER reactor core at change of coolant density. In this paper, fine-grid three-dimensional pin-by-pin power calculation is typically seen as calculation where pin-by-pin power is computed on the finite-difference grid that matches the fuel rod spac-ing in fuel assembly. MCNP-based calculation was used as a benchmark; this calculation was prepared for one of the first fuel loadings of the NPP-2006 reactor. A series of two-dimensional calculations has been performed: in each test the same coolant density over the reactor core (variation of water density from 0.3 to 0.8 g/cm3) is set, coolant temperature is considered as invariable and is 315 °C. Three-dimensional calculation has been performed: different density (range of 0.46-0.73 g/cm3) in ten layers along the core axis is set, coolant temperature is varying from 299 to 348 °C. The influence of number of energy groups on the accuracy of power calculation for fuel rods and gadolinium fuel rods is analyzed. Two-, six- and twelve-group diffusion approximation are calculated. The calculation model is prepared using SAPFIR_95.1 cell calculation program and SAPFIR_95&RC_micro pin-by-pin power calculation program.

Boiling water cooled travelling wave reactor

This study investigates the principal possibility of a boiling-water-cooled travelling wave reactor that can potentially improve the natural uranium utilisation in Boiling Water Reactors (BWRs), and more general in water-cooled reactors, appreciably. A strong variation of the water density along the core height makes favourable the nuclear fission in the lower core part and the fuel breeding in the upper one. A serial axial fuel shuffling scheme is considered for establishing a kind of travelling wave. The fresh natural uranium oxide fuel is loaded from the core top. The irradiated fuel is discharged from the core bottom. The water coolant at the saturation point at a near-atmospheric pressure comes from the bottom of the core, as in conventional BWRs. The asymptotic state of the breeding/burning wave is obtained, including its major characteristics, such as power density distribution, coolant mass flow rate, and the fuel shuffling speed. The employed simulation model for the water density variation in axial direction is based on a slip ratio approximation for two-phase flows. The burn-up calculations are performed with the ERANOS2.2 code, in which the models of axial fuel shuffling and coolant density variation have been implemented. The numerical results for 1D-models are encouraging and show that the breeding performance is sufficient to keep the core critical in the asymptotic state, and a maximum burn-up of about 37% can be reached, meaning that the natural uranium utilization in BWR can be improved by several ten times compared to conventional water-cooled reactors. Feasibility-related issues, such as the void reactivity effect and critical heat flux limit, has been checked and discussed. Further efforts are needed to establish a viable design based on the ideas proposed in the paper.

What Is the Range of Soil Water Density? Critical Reviews With a Unified Model

AbstractThe soil water density is defined as the ratio of soil water mass to soil water volume. It is a cornerstone in defining thermodynamic states of either saturated or unsaturated soils for quantifying water storage and movement in the subsurface and for mechanical stability of landscape. So far, it has been widely treated as identical to the free water density, that is, a constant of 0.997 g/cm3, but can be remarkably different from this value as it is subject to a wide range of variation in energy levels. Some experimental and theoretical evidence indicate that it can be as high as 1.680 g/cm3 and as low as 0.752 g/cm3. However, to date, there is no unanimous agreement upon a reliable experimental method to measure the soil water density or a unified theory to explain why and how the soil water density can deviate remarkably from the free water density. Consequently, the understanding of the soil water density is controversial and elusive, or some theories are contradictory to each other. In this review, the authors will (1) conduct critical reviews on the experimental and theoretical methodologies to identify their limitations, flaws, and uncertainties, (2) synthesize some recent findings on intermolecular forces, interfacial interactions, and soil water retention mechanisms to clarify molecular‐scale physicochemical mechanisms governing the soil water density, and (3) propose a unified model to quantify soil water density variation. It is found that capillarity associated with surface tension tends to generate tensile stress in soil water and thereby decreases the soil water density, whereas adsorption stemmed from cation hydration, surface hydration, and interlamellar cation hydration tends to produce compressive stress thus increases the soil water density. Furthermore, the abnormally high water density greater than 1.15 g/cm3 is a result of cation and surface hydration that involves significant water structure change around exchangeable cations and mineral surface hydroxyls. The unified soil water density model, explicitly quantifying adsorptive and capillary water, could potentially reconcile the unresolved controversies. The critical reviews and the unified model also would allow us to further confine the upper and lower bounds of the soil water density. The upper bound is theoretically inferred to be around 1.872 g/cm3, whereas the lower bound is around 0.995 g/cm3; both are higher than that reported in the literature. With the unified model and measured soil water retention curves, it is demonstrated quantitatively that the soil water density significantly impacts the magnitude of various fundamental soil properties such as matric potential, specific surface area, and volumetric water content. The abnormally high soil water density has significant implications to the conventional concepts of matric potential and pore water pressure in soils and other earthen porous materials.

New Screening tool for Obtaining Concentration Statistics of Pollution Generated by Rivers in Estuaries

Rivers represent an essential pathway for waterborne transport, and therefore estuaries are critical coastal areas for a pollution hazard that might lead to eutrophication and general water quality deterioration. When addressing these problems, the decision makers and coastal managers often need additional skills and specialists, so they engage consultants in developing models and providing potential solutions. Different stakeholders’ interests present a challenge in the implementation process of proposed solutions. Nevertheless, if the relevant institutions were presented with a screening tool, enabling them with a certain level of solution ownership, potentially more involvement would occur. There are numerous intertwined physical processes present in the estuary ecosystem, including river discharge, tidal forces, wind-induced stress and water density variations. This research utilizes an analytical model based on ensemble averaging and near-field approximation of the advective-diffusion equation for the case of continuous, steady, conservative solute transport in a stratified, river-dominated estuary. Such an approach significantly reduces the costs and time needed to obtain enough measured data required for common statistical analysis or the need for a more complex numerical model. The developed methodology is implemented into a simple software named CPoRT (Coastal Pollution Risk Tool) within a recently conducted research project funded by European Social Fund.

Temporal shifts in dominant sulfur-oxidizing chemoautotrophic populations across the Cariaco Basin's redoxcline

A pronounced and relatively stable peak in dark carbon assimilation (DCA) has been observed within the Cariaco Basin's redoxcline over a 19-year observation period, presumably driven largely by sulfur-oxidizing chemoautotrophic bacteria (thioautotrophs). As documented in previous reports, this midwater productivity hotspot is associated with prominent biomass peaks, consisting of prokaryoplankton (Bacteria + Archaea) protists and viruses. Early in the time-series, phylogenetic studies (small subunit ribosomal RNA gene libraries) and fluorescent in situ hybridization (FISH) surveys documented that the chemoautotrophic layer was overwhelmingly populated by ε-proteobacteria related to sulfur-oxidizing symbionts from hydrothermal vent systems and β-proteobacteria. However, after May 2009, β- and ε-proteobacteria were no longer detected in significant numbers by FISH or by more exhaustive sequencing efforts (454 pyrosequencing and MiSeq iTag libraries). Sulfur oxidation gene quantification (qPCR) also confirmed that ε-proteobacteria were rare in samples collected after mid-2009 and that the chemoautotrophic layer became dominated by γ-proteobacterial sulfur-oxidizers (GSOs). Monthly hydrographic and chemical data from the CARIACO Ocean Time-Series were examined for temporal changes that might have driven this shift in the dominant thioautotrophs. Within the redoxcline (250–450 m), significant shifts occurred in water density structure and distributions of H2S, NH4+, O2, and NO2- between the β-/ε-proteobacteria-dominated and the γ-proteobacteria-dominated periods. Contrary to observations in other euxinic systems, GSO seem to have a selective advantage over other sulfur-oxidizing lieages during periods of higher and less variable H2S vertical fluxes and higher relative fluxes of H2S to O2 and NO3-. How exactly this changing seascape might have selected for one lineage over another cannot be directly determined. However, spatiotemporal variations in water density and concentration gradients altered vertical fluxes of the major reductant (H2S) and oxidants (O2, NO3-,NO2-), which we postulate provided a more geochemically stable environment favoring GSOs.

Quantification of history effects in PWR modelling

Nowadays, the application of nodal methods and cross section homogenization is a standard practice in reactor core design and safety studies. Specifically, nodal cross sections are prepared with the planned physical operating conditions in the single fuel assemblies, thus assuming different approximations like for instance a constant exposure at nominal power. Concerning the light water reactors, this scheme was especially suitable for the first PWR units operating on base load, and much less for BWRs due to the strong core heterogeneities and strong axial water density variation which required ad hoc corrections. The new generation of PWRs and yet the current units in Europe show frequent use of control rod elements in order to operate on load-following. In general, the current few group cross section models of core simulators are not designed to cover very long periods of control bank insertions, thus arising the problem of the physical representation. In this work, we quantify the errors on nodal cross sections in presence of strong insertion of control rods, using the classical approach for the cross sections preparation based on a single PWR assembly homogenization. The framework of the Burn-up Credit Criticality Benchmark NEA-6227 (Phase II-D) is used to model different rodded configurations of a UO2 fuel assembly by the lattice code APOLLO2.8, providing also additional validation elements for the code. Different insertion patterns along the multiple core cycles are investigated and differences against the standard cross section generation, which considers the control rods insertion only as a perturbation along the exposure in the nominal depletion sequence, are studied. Still using the framework of this benchmark, other test cases are formulated to investigate the influence of varying boron concentration along the fuel cycles, different water densities and the aging of control elements. In particular, the latter is marked as potential issue when staging a very long insertion as with the main cases of the benchmark. We also discuss mesh refinement to model “the skin effect” when depleting the absorption materials of control rods. The suggestions for the improved modelling are given in the conclusion.

Fuzzy C-Mean Clustering Based Inference System for Saltwater Intrusion Processes Prediction in Coastal Aquifers

Flow as well as salt transport processes of coastal aquifers are dependent on the density variation of water, and are complicated and extremely non-linear in nature. Simulation of these complicated systems to an acceptable degree of accuracy using a suitable surrogate model can be useful to achieve computational efficiency in modelling. In this study, a Sugeno type Fuzzy Inference System (FIS) is developed to predict salinity concentrations at specified monitoring locations as a result of groundwater pumping. Fuzzy c-mean clustering (FCM) algorithm is used to develop the FIS. Heterogeneity of aquifer is incorporated by using different hydraulic conductivities at different layers of the aquifer. A numerical simulation model, FEMWATER is adopted to generate the required patterns of inputs and outputs for initial training of the developed FIS. The FIS analyzed different combinations of antecedent transient pumping values, and returns concentration values at different monitoring locations. The performance of the FIS for training and validation datasets is evaluated by comparing the outputs obtained from the numerical simulation model. The trained and validated FIS is utilized as an approximate simulator of the coupled flow and salt transport processes. It is then used to forecast salt concentrations at different monitoring locations. Performance evaluation results indicate that the developed FIS can be applied to forecast salt concentrations at specified monitoring locations. The FIS is able to simulate the complex physical processes of heterogeneous coastal aquifers, and can be suitable for incorporation in a coupled simulation-optimization technique to develop optimum pumping strategy.

Variation in water density related to pollutants removal in wastewater treatment processes and its use in explaining the working principles of the Unifed SBR.

The wastewater quality of several municipal wastewater treatment plants (MWTPs) in Beijing was studied, and the water densities of different processing units were also measured during the wastewater treatment process. The results clearly showed that the water density declined from influent to effluent of the wastewater treatment process. Meanwhile, the variation in water density had good statistical correlation with the concentrations of total organic carbon, total phosphorus, suspended solids and total solids. Furthermore, the variation in water density could be used to explain the working principles of the Unifed sequencing batch reactor (SBR). Tracer tests were conducted in the Unifed SBR to investigate the hydraulic characteristics of the reactor. The experimental results showed that the variable values of water density from influent to effluent in the Fangzhuang MWTPs were greater than those caused by the temperature difference of >3 °C between the influent and the liquid in the reactor at 13 °C. Moreover, the flow regime of wastewater in the Unifed SBR was affected by the variation in water density, which may lead to stratification or a density current. Ascribed to the appearance of stratification in the Unifed SBR reactor, the water quality of the effluent could not be affected by that of the influent.

A discontinuous Galerkin method for two-layer shallow water equations

In this paper, we study a discontinuous Galerkin method to approximate solutions of the two-layer shallow water equations on non-flat topography. The layers can be formed in the shallow water model based on the vertical variation of water density which in general depends on the water temperature and salinity. For a water body with equal density the model reduces to the canonical single-layer shallow water equations. Thus, for a model with equal density on flat bottom, the method is equivalent to the discontinuous Galerkin method for conservation laws. The considered method is a stable, highly accurate and locally conservative finite element method whose approximate solutions are discontinuous across inter-element boundaries; this property renders the method ideally suited for the hp-adaptivity. Several numerical results illustrate the performance of the method and confirm its capability to solve two-layer shallow water flows including tidal conditions on the water free-surface and bed frictions on the bottom topography.

Study of the Effect of Linear and Parabolic Density Region in Settling Tanks for Potable Water

AbstractComputational fluid dynamics (CFD) methods are employed to evaluate the influence of temperature variations on the flow field in an actual sedimentation tank for potable-water treatment. A series of experimental measurements of temperature variation has been conducted in that sedimentation tank. The mixed-convection problem caused by the density variations and the horizontal stream is considered at low temperatures (0–10°C) where the variation of water density is strongly nonlinear. Three cases have been examined: (1) one in the ascending, (2) one in the descending parabolic density region, and (3) one in the linear density region. The thermophysical properties of water have been incorporated into the CFD code. All simulations have been conducted for a transient, turbulent flow field. The momentum exchange between the primary and the secondary phase (particles) is considered. The results show that in the parabolic density region, only a few particles are trapped in the bottom, whereas many of them...

Numerical simulations of water freezing processes in cavities and cylindrical enclosures

Convection and enthalpy-porosity based solidification solvers have been implemented in the Open source CFD code OpenFOAM to study water freezing phenomena in internal geometries. A polynomial water density variation has been used for the gravity related terms. Liquid to solid phase changes have been accounted for in both energy and momentum equations and the water volume fraction has been modelled with a temperature function in the domain. The models described in this paper have been compared with numerical results obtained with commercial or in-house CFD codes for a squared shape cavity and inside a cylindrical enclosure. When possible, results have also been compared to experimental measurements. This solidification solver has finally been extended and modified to create a novel formulation to account for slurry and mushy regions. It appeared clearly that physical phenomena observed in experiments could be reproduced with high accuracy when using either the solidification solver or the new slurry–mushy solidification solver. For the latter model, a distinction is made between the newly formed ice particles not interacting with each other (slurry region) and the mixture of compact ice and liquid (mushy region). The correct modelling of these two distinct regions is necessary for hydro-carbon industries for instance, where cooling oil can form wax gels.