Mustafa Ozsipahi, Sertac Cadirci, Hasan Gunes, Husnu Kerpicci, Kemal Sarioglu

The aim of this study is to numerically investigate theeffects of various parameters on the lubricant (oil)-coolant two phaseflow in the lubrication system of hermetic compressors commonlyused on household refrigerators. Lubrication oil is pumped from thesump through an asymmetrically opened hole on the bottom of thecrankshaft (suction side or inlet) by its rotational motion and climbsas an oil film on the internal surface of the helical channel carved onthe crankshaft surface. This oil film is directed to crankshaft upperexit discharging into the coolant refrigerant and it is used tolubricate the moving components of the compressor including thecylinder piston. The oil forms an immiscible mixture with coolant,thus a two phase flow model using Volume of Fluid (VOF) method isused. Specifically, the mass flow-rate of oil is determined as afunction of the rotational speed, oil viscosity and the submersiondepth of the crankshaft in the oil-sump. With increasing rotationalspeed and submersion depth, the mass flow-rate through thecrankshaft upper exit also increases. With increasing oil viscosity themass flow-rate through the crankshaft upper exit decreases due to theincreased friction.

Fluid Inclusions and Rare Earth Elements (REE) analysis in calcite veins: Tectonic - diagenesis interaction in the Rosablanca formation, Mesa de los Santos sector, eastern cordillera, Colombia

Studies conducted by means of petrography, cathodoluminescence, SEM, fluid inclusion and REE geochemistry in core samples from the Rosablanca Formation in the Mesa de Los Santos sector, identified two types of material: the host rock classified as Packstones and Grainstones, and veins that texturally expose three types of filling (blocky texture, blocky elongate texture, fibrous texture). Diagenesis is characterized by dissolution, carbonate cement precipitation, compaction, fracturing and fluid circulation through fractures during at least three episodes; these diagenetic processes were contemporaneous with the distensive and compressive tectonic regimes regionally dominant during the Cretaceous, Paleogene and Neogene in the study area. The fluids that generated the different types of texture inside the veins were brines that belonged to the H2O – NaCl – CaCl2 system, with salinities between 0.03 – 12.96 % wt eq NaCl, derived from the Rosablanca Formation that was deposited under oxic conditions, retaining their marine character and implying an autochthonousorigin for the REE present in the veins. The conditions of entrapment for fluid inclusions during the early event were heterogeneous, arising from an immiscible mixture of brines andhydrocarbons, while in the second, they were homogeneous with later post-entrapment processes.later post-entrapment processes.

Synthesis of hexagonal MoO3 nanorods and a study of their electrochemical performance as anode materials for lithium-ion batteries

h-MoO3 nanorods with a diameter of 40 nm are synthesized in an immiscible mixture of solutions and exhibit high electrochemical performance.

AN LBM-BASED INVESTIGATION METHOD FOR THERMAL IMMISCIBLE MIXTURE FLUID FLOW IN RECTANGULAR MULTI-JET CAVITY

An investigation method for thermal immiscible mixture fluid flow in rectangular multi-jet cavity using lattice Boltzmann method (LBM) is presented to study influence of controllable factors on quality of mixture generated from the cavity. For immiscible mixture flow, contact area of fluids has great effect on generated mixture. The basic idea is to investigate the relationship between controllable factors and contact area of key components. The contact area is obtained through numerical simulation by an improved LBM, in which temperature equation is extended to multicomponent system. A case study of thermal mixture flow in three-jet cavity using the present method is shown.

THE EFFECT OF VISCOSITY ON THE PHASE SEPARATION DYNAMICS OF BINARY IMMISCIBLE MIXTURE COUPLED WITH REVERSIBLE REACTION

The phase-separating system coupled with a simple reversible reaction A ⇌ B in a binary immiscible mixture due to critical quench is investigated with Lowe-Andersen temperature controlling method in two dimensions. The system viscosity strongly influences the asymptotic relationship between the excess energy (characterizing the domain growth) and the reaction rate. The competition between different dynamic factors results in the steady states with characteristic domain sizes. For low viscosities, the domain growth exponent approximates to 0.4 in the cases of low reaction rates and to 0.25 in the cases of high reaction rates, which shows the suppressing effects of high reversible reaction rates on the phase separation. However, in the cases of high viscosities, we find a 0.25 scaling with low reaction rates but a 0.5 scaling with high reaction rates. In these cases, high viscosities prevent mass transport in the binary mixture, consequently result in much smaller steady state domain sizes. Therefore the domain sizes with high viscosities and low reaction rates are very similar to those with low viscosities and high reaction rates, and the dependence of domain sizes on the reaction rates are similar. For the high-viscosity systems with high reaction rates, the domain sizes are predominantly controlled by the reaction rates, therefore we can observe stronger dependence of domain size on the reaction rate.