Solid composite propellants often contain metal particles, such as aluminum and the internal flow field in a solid rocket motor is typical gas–solid two-phase field. In this study, to address problem of erosion particles on wall during working process an engine, particle model was established based interaction mechanism between wall. From perspective dynamics, moving analyzed. The force surface...

Inverse gas chromatography (IGC) represents a unique refinement of a classic chromatographic method has the potential to unlock some of the more difficult to measure physicochemical properties of pharmaceutical materials such as powder surface energies, acid/base/polar functionality of surfaces, diffusion kinetics, solubility parameters, surface heterogeneity and phase transition temperatures/h...

Quantitative agreement with experimental data for adsorption of argon, krypton, and methane in high-silica zeolites is achieved with a molecular model, which (1) assumes pairwise additivity of intermolecular forces; (2) ignores partially concealed silicon atoms and lumps their dispersion energy with the oxygen atoms; (3) neglects energy induced by the weak electric field inside silicalite; (4) ...

The ground-state properties of spin polarized hydrogen H↓ in two dimensions (2D) are obtained by means of diffusion Monte Carlo calculations. Using the most accurate to date ab initio H↓–H↓ interatomic potential we have studied hydrogen gas phase, from the very dilute regime until densities above its freezing point. For very low densities, the equation of state of the gas can be described in te...

Catalytic converters are used for minimizing the release of pollutants to the atmosphere. It is during the warm-up period that hydrocarbons are seen to be released in appreciable quantities from these converters. In this paper the conversion of a fast oxidizing hydrocarbon propylene is analysed using two numerical methods. The quasi steady state method assumes the accumulation terms to be negli...

In the standard model of gas giant planet formation, a large solid core (∼ 10 times the Earth’s mass) forms first, then accretes its massive envelope (100 or more Earth masses) of gas. However, inward planet migration due to gravitational interaction with the proto-stellar gas disk poses a difficulty in this model. Core-sized bodies undergo rapid “Type I” migration; for typical parameters their...

The numerical simulation of fully developed gas–solid flow in a horizontal pipe is done using the eulerian-eulerian approach, also known as two fluids modeling as both phases are treated as continuum and inter-penetrating continua. The solid phase stresses are modeled using kinetic theory of granular flow (KTGF). The computed results for velocity profiles and pressure drop are compared with the...

Current research has identified Duplex pellets as an effective strategy for decreasing the centerline temperature of the fuel. However, before this design can be widely utilized several areas, including fission gas release, need to be better characterized. Therefore, this paper seeks to ascertain the relative difference in fission gas release between a standard solid UO2 reference design and a ...

The temperature dependence of the irreversible phase transition from a two-dimensional gas to an ordered zero-dimensional solid on the Si(111)-7 × 7 surface was studied using photoemission spectroscopy. With increasing Na coverage, the two-dimensional Na gas, which is a state of highly mobile Na atoms, undergoes a phase transition into ordered zero-dimensional magic nanoclusters at room tempera...

This thesis proposes a way to simulate the interaction of fluids and solids based on the Smoothed Particle Hydrodynamics method. The interaction is facilitated by not only representing fluids with particles, but solid objects as well. Linear elastic forces are computed between neighbouring particles to create deformable objects. The animation of fully rigid objects is made possible by introduci...