W‌a‌t‌e‌r v‌a‌p‌o‌r c‌o‌n‌t‌a‌i‌n‌s l‌i‌q‌u‌i‌d d‌r‌o‌p‌l‌e‌t‌s a‌t l‌o‌w p‌r‌e‌s‌s‌u‌r‌e s‌t‌a‌g‌e‌s o‌f a s‌t‌e‌a‌m t‌u‌r‌b‌i‌n‌e, a‌n‌d t‌h‌i‌s t‌w‌o-p‌h‌a‌s‌e f‌l‌o‌w c‌a‌n b‌e m‌o‌d‌e‌l‌e‌d a‌n‌a‌l‌y‌t‌i‌c‌a‌l‌l‌y (m‌a‌t‌h‌e‌m‌a‌t‌i‌c‌a‌l‌l‌y) i‌n a o‌n‌e d‌i‌m‌e‌n‌s‌i‌o‌n‌a‌l c‌o‌n‌v‌e‌r‌g‌e‌n‌t-d‌i‌v‌e‌r‌g‌e‌n‌t n‌o‌z‌z‌l‌e. T‌h‌e m‌a‌i‌n g‌o‌a‌l o‌f t‌h‌i‌s p‌a‌p‌e‌r i‌s t‌o i‌n‌v‌e‌s‌t‌i‌g‌a‌t‌e t‌h‌e e‌f‌f‌e‌c‌t o‌f d‌i‌f‌f‌e‌r‌e‌n‌t s‌t‌a‌t‌e e‌q‌u‌a‌t‌i‌o‌n‌s a‌n‌d t‌h‌e‌r‌m‌o-p‌h‌y‌s‌i‌c‌a‌l p‌r‌o‌p‌e‌r‌t‌i‌e‌s o‌f w‌a‌t‌e‌r v‌a‌p‌o‌r o‌n m‌o‌d‌e‌l‌i‌n‌g t‌h‌e p‌e‌r‌f‌o‌r‌m‌a‌n‌c‌e o‌f a s‌u‌p‌e‌r‌s‌o‌n‌i‌c t‌w‌o-p‌h‌a‌s‌e f‌l‌o‌w. I‌n t‌h‌i‌s r‌e‌s‌e‌a‌r‌c‌h, f‌o‌r t‌h‌e f‌i‌r‌s‌t t‌i‌m‌e, t‌h‌e v‌i‌r‌i‌a‌l e‌q‌u‌a‌t‌i‌o‌n‌s o‌f s‌t‌a‌t‌e p‌r‌o‌p‌o‌s‌e‌d b‌y V‌u‌k‌a‌l‌o‌v‌i‌c‌h, a‌n‌d t‌h‌e r‌e‌l‌a‌t‌e‌d s‌t‌e‌a‌m p‌r‌o‌p‌e‌r‌t‌i‌e‌s, h‌a‌v‌e b‌e‌e‌n c‌o‌m‌p‌a‌r‌e‌d w‌i‌t‌h t‌h‌e s‌t‌a‌t‌e e‌q‌u‌a‌t‌i‌o‌n‌s a‌n‌d t‌h‌e e‌q‌u‌a‌t‌i‌o‌n‌s o‌f t‌h‌e t‌h‌e‌r‌m‌o-p‌h‌y‌s‌i‌c‌a‌l p‌r‌o‌p‌e‌r‌t‌i‌e‌s o‌f v‌a‌p‌o‌r i‌n A‌S‌M‌E s‌t‌e‌a‌m t‌a‌b‌l‌e‌s p‌u‌b‌l‌i‌s‌h‌e‌d i‌n 2006. T‌h‌e p‌r‌i‌n‌c‌i‌p‌a‌l g‌a‌s-d‌y‌n‌a‌m‌i‌c d‌i‌f‌f‌e‌r‌e‌n‌t‌i‌a‌l e‌q‌u‌a‌t‌i‌o‌n‌s o‌f t‌h‌e t‌w‌o-p‌h‌a‌s‌e f‌l‌o‌w a‌r‌e s‌o‌l‌v‌e‌d b‌y t‌h‌e R‌u‌n‌g‌e-K‌u‌t‌t‌a t‌e‌c‌h‌n‌i‌q‌u‌e. I‌n t‌h‌i‌s r‌e‌g‌a‌r‌d, t‌h‌e p‌r‌o‌p‌o‌s‌e‌d n‌u‌c‌l‌e‌a‌t‌i‌o‌n a‌n‌d d‌r‌o‌p‌l‌e‌t g‌r‌o‌w‌t‌h e‌q‌u‌a‌t‌i‌o‌n‌s, a‌n‌d, a‌l‌s‌o, t‌h‌e e‌q‌u‌a‌t‌i‌o‌n‌s o‌f s‌t‌a‌t‌e a‌n‌d t‌h‌e‌r‌m‌o-p‌h‌y‌s‌i‌c‌a‌l p‌r‌o‌p‌e‌r‌t‌i‌e‌s f‌r‌o‌m t‌h‌e t‌w‌o a‌b‌o‌v‌e m‌e‌n‌t‌i‌o‌n‌e‌d r‌e‌f‌e‌r‌e‌n‌c‌e‌s a‌r‌e u‌s‌e‌d. T‌h‌e r‌e‌s‌u‌l‌t‌s h‌a‌v‌e b‌e‌e‌n c‌o‌m‌p‌a‌r‌e‌d w‌i‌t‌h t‌h‌e e‌x‌p‌e‌r‌i‌m‌e‌n‌t‌a‌l d‌a‌t‌a, i‌n‌c‌l‌u‌d‌i‌n‌g t‌h‌e p‌r‌e‌s‌s‌u‌r‌e r‌a‌t‌i‌o a‌n‌d d‌r‌o‌p‌l‌e‌t d‌i‌a‌m‌e‌t‌e‌r. A‌c‌c‌o‌r‌d‌i‌n‌g t‌o t‌h‌e r‌e‌s‌u‌l‌t‌s, f‌o‌r i‌n‌l‌e‌t s‌t‌a‌g‌n‌a‌t‌i‌o‌n p‌r‌e‌s‌s‌u‌r‌e‌s a‌n‌d t‌e‌m‌p‌e‌r‌a‌t‌u‌r‌e‌s l‌e‌s‌s t‌h‌a‌n 1.5 b‌a‌r‌s a‌n‌d 400 K‌e‌l‌v‌i‌n, r‌e‌s‌p‌e‌c‌t‌i‌v‌e‌l‌y, t‌h‌e e‌q‌u‌a‌t‌i‌o‌n‌s p‌r‌o‌p‌o‌s‌e‌d i‌n t‌h‌e A‌S‌M‌E s‌t‌e‌a‌m t‌a‌b‌l‌e‌s a‌r‌e m‌o‌r‌e a‌c‌c‌u‌r‌a‌t‌e t‌h‌a‌n t‌h‌e o‌t‌h‌e‌r e‌q‌u‌a‌t‌i‌o‌n‌s. B‌u‌t, f‌o‌r h‌i‌g‌h‌e‌r i‌n‌l‌e‌t p‌r‌e‌s‌s‌u‌r‌e‌s a‌n‌d a‌l‌s‌o i‌n‌l‌e‌t t‌e‌m‌p‌e‌r‌a‌t‌u‌r‌e‌s u‌p t‌o 600 K‌e‌l‌v‌i‌n,V‌u‌k‌a‌l‌o‌v‌i‌c‌h's v‌i‌r‌i‌a‌l e‌q‌u‌a‌t‌i‌o‌n o‌f s‌t‌a‌t‌e a‌n‌d r‌e‌l‌a‌t‌e‌d s‌t‌e‌a‌m p‌r‌o‌p‌e‌r‌t‌i‌e‌s a‌r‌e s‌u‌g‌g‌e‌s‌t‌e‌d.

In this research, utilization of typical moisture separation process in conventional steam cycle power plants, for NPPs are recommended; and by applying CFD, two-phase flow of this process is simulated. Results show that with increasing of loading, the pressure drop across the separator increases, and a linear relationship between pressure drop and inlet flow kinetic energy density is established. Also, with increasing inlet width, pressure drop decreases and the efficiency increases. However, excessive increasing of input width leads to a decrease in mass flow at lateral outputs. Study on the variation of lateral outlet diameter show that variation of mentioned parameter does not affect pressure drop and efficiency significantly, but reducing of that lead to increasing lateral out let steam mass fraction. Based on the performed assessment, horizontal steam separator as a component with desirable efficiency and pressure drop, can be recognized as a suitable option for utilization in small and low power NPPs as well as propulsion systems. For validation, an analysis of two phase flow in a vertical cylinder cyclone is performed and results show good agreement with experimental data.

Steam flow at blade passages of low pressure steam turbines becomes a supercooled drysteam due to rapid expansion and crossing the saturation line. But after nucleation and condensation shock, phase change from vapor to liquid droplets occurs which is called two-phase or wet steam flow. In this paper, the aim of developing finite-volume flow of wet Jameson is considered for the first time in two-dimensional study by using the advantages of CUSP's numerical method. In this paper, equations governing the formation of liquid phase are combined with equations of survival and by using CUSP's numerical approach in Jameson's finite-volume method (the integrated method) the positive features of both of these methods can be simultaneously used in the modeling of two-phase flow. To calculate nucleation, the classical equation of nucleation with appropriate correction and also Lagrangian solution for growth of droplets are used in integrated method. Additionally, condensation shock effect on the pressure distribution and the droplet size has been calculated and compared with experimental data. Given the importance of areas of shocks on the suction surface of the blade, the focus of integrated method is shifted to this area. The results of integrated two-phase model are examined in subsonic and supersonic flow output. In the shock area on suction surface blade, using the CUSP's method (the integrated method) demonstrates better coverage in predicting attributes of flow in target area in comparison with the experimental data by a reduction of 20 percent in numerical errors.

In the PEM fuel cells, gas phase (air and vapour) and liquid water could simultaneously flow through the cathode Gas Diffusion Layer (GDL). On the other hand, the performance of fuel cell and the main characteristic parameters of the flow can be influenced by the interaction of these gas and liquid phases. In the present study, the main parameters of two-phase flow in the GDL such as capillary pressure, mole concentrations of gas species, gas velocity and liquid velocity have been evaluated by considering the interactional effects of the aforementioned two phases. Also, the impact of changing the value of cathode channel humidity and fuel cell temperature on the value of the mentioned parameters has been investigated. The results indicated that decreasing of relative humidity in the cathode channel causes an increase in the rate of water vaporization. Thus, this leads to a decrease in the liquid water velocity, capillary pressure gradient and saturation gradient in the GDL. Also, increasing the temperature causes an increase in the rate of water vaporization and a decrease in the gas velocity and gas pressure gradient.

In the present paper, the simulation of droplet dynamics and its breakup process in the cross flow of cold and hot gases are performed. Herein, the Navier-Stokes equations are used with employing two additional equations for tracking the liquid-gas interface and for computing the mass transfer due to the evaporation and condensation. Accuracy of the applied numerical algorithm is evaluated by simulation of the Stefan heat transfer problem, two-phase laminar Couette flow, and comparison of the present numerical results with those obtained based on the analytical solution. The dynamics of a droplet break-up in the cold gas are studied and the obtained results are discussed. Then, the study is carried out for the simulation of droplet dynamics in the cross flow of hot gas and the effect of the evaporation on the break-up process is investigated. The present study shows that the aerodynamics forces and Rayleigh-Taylor and Kelvin-Helmholtz instabilities have dominant effects on the droplet dynamics in the cold gas. However, for a droplet in the cross-flow of hot gas, evaporation has a significant effect on the deformation and breakup phenomenon.

Surface roughness of steam turbine blades is increased during operation. This point has harmful effect on the performance of steam turbines. In this paper effects of surface roughness on performance of a steam turbine stage in two-phase flow conditions are investigated for different outlet pressures. To do so a numerical code has been developed to simulate two-phase non-equilibrium flow in 2D steam turbine geometry. An AUSM-van Leer hybrid scheme is used to calculate inviscid fluxes, the SST turbulence model for turbulence viscosity and Wilcox roughness model for implementation of roughness on the surface of turbine blade. To validate the present in-house code the experimental results of Bakhtar has been used. According to the results of the paper, effect of surface roughness variation on the performance loss in subsonic stages is more than that in supersonic outflows. For example, in subsonic outflow case (Pb= 24.25 kPa) when the roughness height increases from 5µm to 800 µm, the value of efficiency decreases by 15%. However, for supersonic outflow case (Pb= 14.55 kPa) the value of efficiency decreases by 10% for this roughness increase.

In this paper complex fluid flow and transport phenomena in plate-fin heat exchanger for LNG process are investigated. Modeling and simulation of heat transfer and fluid flow has been done using ANSYS Fluent software. This software has limitation in simulation of multispecies biphasic flow; therefore, UDF.A 2D model was used for modeling aforementioned phenomena in one channel of heat exchanger. HYSYS software was used for calculation of species equilibrium concentration and it was linked to ANSYS using UDF. Results shows that vapor volume fraction, species composition and heat transfer coefficient for CFD and Aspen muse are in good agreement, but pressure drop is over predicted by Aspen Muse. Using the developed model, a good deal of information was obtained about transport phenomena and fluid flow in cryogenic heat exchangers, while other software packages could not provide that much information.

Under modern direct injection diesel engine conditions, the spray and combustion processes are known to be controlled by mixing. In large eddy simulation method, large eddies are solved directly and small scales are modeled, so it can potentially improve the predictive capability by better capturing the large-scale mixing of ambient air with the fuel vapor. In this paper, turbulent spray combustion is studied using the large eddy simulation method together with partially stirred reactor model using EPISO- SPRAY code. To develop this code, large eddy simulation method is applied in an Eulerian – Lagranian approach in which conservation equations of both phases are solved and then results of large eddy simulation are compared with those of Reynolds averaged of Navier-Stocks. Simulation of spray combustion using different sub-grid scale models of large eddy simulation method (Simple Smagorinesky and dynamic Smagorinesky) with partially stirred reactor combustion model are presented here. It is shown that with a fine mesh, results are in good agreement with experimental data. Results of non-reacting spray penetration length in gas environment and velocity profile during the intake stage are compared with related experimental data in order to validate the EPISO-SPRAY code performance. It is proved in this study that large eddy simulation results with relative fine mesh are much better than the Reynolds-averaged Navier–Stokes equations results. Results of reacting liquid spray using simple step kinetic and fuel vapor penetration length are compared with experimental data. It is shown that overall characteristics of diesel spray combustion such as liquid spray penetration and fuel vapor penetration are both in good agreement with experimental data using Reynolds-averaged Navier– Stokes equations or large eddy simulation models. Although small differences in the flame shape are seen with the two methods, maximum and minimum temperatures are predicted to be the same in both models.

Determination of multiphase flow dynamics and thermal behavior of falling flow in a channel and around a cylinder are of importance due to its wide application in various industries. The small-scale surface tension effect plays a major role in multiphase flow behavior. So, based on simulation efficiency, precision, and stability, the mesoscopic Lattice Boltzmann method superiority has caused its broadening application. In the current study, the thermal-hydraulic behavior of subcooled falling flow in a vertical channel and around a single horizontal tube is simulated by using Lee method and Phase-Filed model, and thermal Passive Scalar model. The modified Boundary conditions for curved tube and two different boundary conditions for side boundaries are investigated. Simulations have been done for density ratio 20 and relevant viscosity and conductivity ratios of water. The film of liquid falls on a tube with a temperature of 110˚C and the outside diameter of 28.9mm. The results including contours and streamlines of the flow field, temperature, and pressure contours are presented and detailed understanding about the movement of the three-phase contact line, circulating flow and local and average Nusselt number are determined. The film thickness, thermal boundary layer variation by the film thickness, Reynold number effect on Nusselt number and mass conservation are investigated as verification. The results have shown good consistency and high effectiveness in the simulation of multiphase gas-liquid flows in the presence of a circular obstacle, and for viscosity and thermal diffusivity ratios of water.

A wide variety of world-class porphyry Cu deposits occur in the Urumieh-Dohktar magmatic arc (UDMA) of Iran.The arc is composed of calc-alkaline granitoid rocks, and the ore-hosting porphyry intrusions are dominantly granodiorite to quartz-monzonite (Zarasvandi et al., 2015). It is believed that faults played an important role in the emplacement of intrusions and subsequentporphyry-copper type mineralization (Shahabpour, 1999). Three main centers host the porphyry copper mineralization in the UDMA: (1) Ardestan-SarCheshmeh-Kharestan zone, (2) Saveh-Ardestan district; in the central parts of the UDMA, hosting the Dalli porphyry Cu-Au deposit, and (3) Takab-Mianeh-Qharahdagh-Sabalan zone. Mineralized porphyry coppersystems in the UDMA are restricted to Oligocene to Mioceneintrusions and show potassic, sericitic, argillic, propylitic and locally skarn alteration (Zarasvandi et al., 2005; Zarasvandi et al., 2015). In the Dalli porphyry deposit, four hydrothermal alteration zones, includingpotassic, sericitic, propylitic, and argillic types have been described in the two discrete mineralized areas, namely, northern and southern stocks. Hypogenemineralization includes chalcopyrite, pyrite, and magnetite, with minor occurrences of bornite.Supergene activity has produced gossan, oxidized minerals and enrichment zones. The supergene enrichment zone contains chalcocite and covellite with a 10-20 m thickness. Mineralization in the northern stock is mainly composed of pyrite and chalcopyrite. The aim of this study is the investigation and classification of hydrothermal veins and the constraining of physicochemical compositions of ore-forming fluids using systematic investigation of fluid inclusions. Twenty samples were collected from drill holes. Thin and polished sections were prepared from hydrothermal veins of thepotassic, sericitic and propylitic alteration zones. Samples used for fluid inclusion measurements were collected from drill cores DH01, DH02, DH06, and DH07, and outcrop samples. Microthermometric data were obtained by freezing and heating of fluid inclusions on a Linkam THMSG600 mounted on an Olympus microscope at Lorestan University. 1) Five main veintypes were identified, belonging to three stages of mineralization:type (I): barren quartz, type (II): quartz + pyrite + chalcopyrite ± bornite ± chalcocite ± covelite, type (III): quartz + magnetite ± chalcopyrite, type (IV): K-feldspar± quartz ± chalcopyrite, type (V): chlorite + biotite. 2) Seven groups of fluid inclusionswere observed: (IA) liquid-rich mono-phase, (IB) vapor-rich mono-phase, (IIA) liquid-rich two-phase (liquid + vapor), (IIB) vapor-rich two-phase (vapor + liquid), (IIIA) high salinity simple fluids (liquid + vapor + halite), (IIIB) high salinity opaque mineral-bearing fluids (liquid + vapor + halite + pyrite + chalcopyrite + hematite), (IIIAB) multi-phase fluids (liquid + vapor + halite + sylvite + hematite + magnetite + pyrite + chalcopyrite ± erythrosiderite) 3) Multiphase fluid inclusions with predominant homogenization temperatures 420 to 620˚C and predominant salinities 70 to 75 wt.%NaCl, are thought to be the early fluids involved in mineralization. 4) The coexistence of high saline liquid and vapor rich fluid inclusions (IIIAB, IIIB, IIIA and IIA types) resulted either from fluid entrapment during the boiling process or the co-presence of two immiscible fluids generated from the magma. 5) Dalliporphyry Cu-Au deposit was formed in a magmatic-meteoric system. Two conventional thermometric procedures, freezing and heating, were employed for the measurement of temperature of homogenization and approximate salinity. Freezing was conducted mainly for halite-under saturated inclusions (types IIA and IIB), to measure the initial melting temperature (Te) and the last melting point (Tmice), whereas heating was carried out on the halite-bearing inclusions (types IIIA, IIIB and IIIAB). Based on the microthermometric results, the Dalli fluid inclusions can be divided into two distinct groups: (1) medium-high temperature, hypersaline (Types IIIA, IIIB and IIIAB) and (2) low-medium temperature, low salinity group (Types IIA and IIB). Type IIB inclusions, which homogenize to the vapor phase and have a relatively low cooling rate, provide a fairly good estimate of entrapment pressure (Roedder and Bodnar, 1980). Based on the pressure estimated for the Dalli deposit, mineralization likely occurred at depth of 0.6-1.1 km. The calculated depth is coincident with the estimated mineralization depths of the porphyry deposits in the world (Pirajno, 2009). Fluid inclusions with a wide range of vapor and liquid ratios are abundant in all of the Dalli samples. This represents heterogeneous trapping of liquid and vapor. The coexistence of inclusions with different volumes of vapor contents, which homogenize either to liquid (Th(L-V)) or vapor (Th(V-L)), are interpreted as an evidence for the prevailing wide range of physico-chemical conditions during the cooling history of ore-forming fluid at the Dalliporphyry Cu-Au deposit. The boiling process is documented by the abundance of heterogeneously trapped fluid inclusions with extremely variable liquid to vapor ratios (Ahmad and Rose, 1980). Acknowledgements: We thank of ShahidChamran University of Ahvaz for their support and moreover, Lorestan University for microthermometric studies.