In this paper, we explore the Rayleigh–Taylor instability (RTI) considering experimental conditions from open literature. simulations real properties are considered, facilitated by dimensional lattice Boltzmann method. First, numerical solution is validated with reference. Usually in literature RTI employed as a benchmark, comparing their solutions some numeric or However, not always same fluid used, only Reynolds (Re) and Atwood (At) numbers kept equal comparison made using dimensionless...

The present research will provide an analytical explanation to experiments destabilising turbulence in pipe flow reported Kuehnen et al. ( Nat. Phys. , vol. 14, 2018, 386–390). Those show four methods by which vanishes from steady-state flow, without decreasing its bulk velocity, until it becomes completely laminar. is based on our theory of underlying laminar (TULF), has already been successfully applied account for other uncommon the literature. TULF founded Reynolds-averaged Navier–Stokes...

The study of single bubble nucleation, growth and detachment processes has being carried out with remarkable relevance in the last fifty years. complexity associated phenomena are still a challenge for researchers field, yielding lot works trying to explain enrolled mechanisms. These studies include experimental, numerical even theoretical approaches. In particular but not exclusively approaches, it is essential importance having solid detailed experimental description full event. It this...

The aim of the reported investigation is to asses effect brownian and thermophoretic diffusion in nanofluids convective heat transfer. In order capture these effects, a new equation for particles distribution had be consider. Momentum energy equations have been reformulated include thermophretic diffusion. These modes suggested extensively literature but their on momentum transport has not yet numerically analyzed. obtain solution modified set governing equations, CFD solver devised. applied...

This research presents a new theory that explains analytically the behaviour of any fully developed incompressible turbulent pipe flow, steady or unsteady. We propose name underlying laminar flow (TULF), because its main consequence is description as sum two components: (ULF) and purely component (PTC). use framework TULF to explain most important interesting phenomena reported in He & Jackson ( J. Fluid Mech. , vol. 408, 2000, pp. 1–38). To do so, we develop simple model for pressure...

Experimental evidence yields a wide variety of starting turbulent pipe flows, usually with greatly deformed mean velocity profiles. Some experimental tests attain profiles maximum values in the near-wall region, while some others report well-defined local concavities within globally convex To authors’ knowledge, no available explanation yet exists for such kind behavior. This theoretical research studies specific effects that certain patterns Reynolds shear stress cause on field obtained...

The pseudopotential Lattice Boltzmann Method has attracted much attention in the recent years for simulation of boiling heat transfer. Many studies have been published recently bubble cycle (nucleation, growth and departure from a heated surface). This paper puts forward two-dimensional simulations nucleation, using an improved Model literature at different reduced temperatures, Tr=0.76 Tr=0.86. Two models Bhatnagar–Gross–Krook (BGK) Multiple-Relaxation-Time (MRT) collision operators with...

An analytic model (AM) describes the dynamical behavior of a Newtonian fluid that is suddenly released to atmosphere from pressurized vessel. The discharge process very fast transient phenomenon in which liquid transits rest highly turbulent motion, constituting two-phase flow with liquid–air interface. AM has number parameters can be adjusted conform experimental or simulation data. This then used assess ability some relevant computational dynamics (CFD) turbulence models simulate described...

A computational methodology is proposed and applied to calculate the temperature effectiveness, P, logarithmic mean difference (LMTD) correction factor, F, of TEMA E shell-and-tube heat exchangers with one-pass fluids flowing in counter-flow. An arbitrary number baffles considered along three different mixture conditions shell-side fluid. The based on various modeling considerations adopted several publications addressing crossflow exchangers. Each section between two idealized as a...

This research reports the mean-velocity field associated with a general plane-parallel flow, regardless of its being laminar, turbulent, steady-state, unsteady, or transient. The Reynolds-averaged Navier–Stokes equation is posed, proper initial and boundary conditions, solution developed in an easy-to-follow fashion. time-dependent analytic obtained, which sum three components: (i) transient decay mean velocity, (ii) unsteady velocity directly created by pressure gradient, (iii) originated...

In naval construction, process automation is essential to improve efficiency and ensure accuracy at every stage of production. this context, machine vision plays a key role by allowing the automatic identification several components. This study will propose system that jointly apply 3D surface matching edge techniques for minor simple pre-assemblies, which are small sub-assemblies part larger structure ship. The combination these be used evaluate their effectiveness in identifying...