This note outlines how the coupling between the motion of rigid bodies immersed in a fluid and the motion of this fluid is handled in XNS. For a rigid body one has a group of nodes which define the surface of the rigid body called “reference node group” (RNG). For each RNG we save the properties of motion in arrays which in the following we will call “RNG arrays”. They contain the bottom and to...

The present work considers the modeling of turbulent flow in reed type valves of reciprocating compressors and is based on a simplified geometry of the actual valve, that is, a radial diffuser with axial feeding. Despite its simplicity the geometry chosen for the analysis has important flow features present in practical geometries. Due to its claimed capability to predict flow including feature...

The turbulent flow in a tangential inlet / tangential outlet vortex tube is numerically simulated using a modified   k turbulence model. The results are compared to experimental measurements from literature. The modified model shows better agreement with the local tangential velocity measurements compared to the standard and RNG   k turbulence models. The flow structure is also demonstrated...

We adopt the following rules: i, j, k, n denote natural numbers, a, b, c, x denote sets, and r denotes a real number. The following four propositions are true: (1) If 1 < i, then 0 < i − 1. (2) If 1 ¬ i, then i − 1 < i. (3) 1 is odd. (4) Let given n, f be a finite sequence of elements of E T , and given i. If 1 ¬ i and i + 1 ¬ len f, then fi ∈ rng f and fi+1 ∈ rng f. This work has been partiall...

In this research, the performance of nonlinear k-ε turbulence model in resolving the time delay between mean flow changes and its proportionate turbulent dissipation rate adjustment was investigated. For this purpose, the ability of Launder-Spalding linear, Suga non-linear, Yakhot RNG and Rietz modified RNG k-ε models are compared in the estimation of axial mean velocity profile and turbulent i...

The purpose of this paper is to evaluate the effects of a building parameter, namely ceiling configuration, on indoor natural ventilation. The computational fluid dynamics (CFD) code Phoenics was used with the RNG k-ε turbulence model to study wind motion and ventilation flow rates inside the building. All the CFD boundary conditions were described. The simulation results were first validated b...