Abstract Reserves of fossil primary energy carriers are limited. Consequently liquid secondary especially for mobile applications made from reserves will not carry on forever but need to be replaced in a not‐to‐far future. Two substitution strategies currently under investigation – the use oil plant seeds either directly or after chemical modification (biodiesel) gasification complete plants, product gases (mainly CO and H 2 ) Fischer‐Tropsch process with subsequent refining. A third...

Plasma sprayed thermal barrier coatings (TBCs), applied in internal combustion engines, can have a profound impact on the apparent rate of heat release. Upon fuel jet contact with piston wall, loss seems to increase compared an uncoated and appears delayed. Permeable porosity plasma TBCs is identified as one possible causes for this unwanted effect. In article open sealing TBC surface are investigated single cylinder engine experiments simulations. Based results, mechanism presented explain...

We present a second order sharp interface finite volume method for the solution of three-dimensional elliptic equation ∇·(β(x→)∇u(x→))=f(x→) with variable coefficients on Cartesian grids. In particular, we focus problems discontinuities in coefficient, source term, solution, and fluxes across interface. The uses standard piecewise trilinear elements normal cells double ansatz intersected by resulting always compact 27-point stencil. Singularities associated vanishing partial volumes grid are...

In this paper the characteristics of primary breakup a liquid jet is analyzed numerically. We applied Volumes Fluids (VOF) approach utilizing Direction Averaged Curvature (DAC) model, to estimate interface curvature, and Normal (DAN) propagate interface. While being used for first time predict atomization, methodology showed high accuracy. The influence varying fluid properties, namely liquid-gas density viscosity ratio, injection conditions discussed related required grid resolution....

Dust formation in turbulent media is studied adopting the example of brown dwarf atmospheres. By combining asymptotic techniques and time-dependent, multi-dimensional numerical simulations, we show that acoustic waves originating from convective motions provide a mechanism to initiate dust nucleation otherwise dust-hostile environments. The subsequently growing particles cause radiative cooling strong enough re-initiate efficient resulting strongly inhomogeneous distribution such Recent...

The objective of this investigation was to improve the thermal properties plasma sprayed barrier coatings (TBC) for internal combustion engines. There is a need further reduction ...

The effect of two thermal barrier coatings and their surface roughness on heat transfer, combustion, emissions has been investigated in a single-cylinder light-duty diesel engine. evaluated coating materials were plasma-sprayed yttria-stabilized zirconia hard anodized aluminum, which applied the piston top surface. main tool for investigation was cylinder pressure analysis high-pressure cycle, from apparent rate release, indicated efficiency, losses derived. For verification calculated wall...

LES–LEM is a simulation approach for turbulent combustion in which the stochastic Linear Eddy Model (LEM) used sub-grid mixing and closure Large-Eddy Simulation (LES). LEM resolves, along one-dimensional line, all spatial temporal scales, provides on-the-fly local flame statistics, captures finite rate chemistry effects directly incorporates turbulence-chemistry interaction. However, computationally expensive as it requires advancing an LEM-line each LES cell. This paper introduces novel...

Abstract The development of gasoline spray at ultra-high injection pressures was analyzed using Large-Eddy simulation (LES). Two different nozzle hole geometries, divergent and convergent shape, were considered to inject the fuel ranging from 200 1500 bar inside a constant volume chamber maintained atmospheric conditions. discrete droplet phase treated Lagrangian formulation together with standard sub-models. numerical results calibrated by reproducing experimentally observed liquid...

The flame stabilisation process in turbulent non-premixed flames is not fully understood and several models have been developed to describe the turbulence–chemistry interaction. This work compares performance of multiple Representative Interactive Flamelet (mRIF) model, Volume Reactor Fraction Model (VRFM), Well-Stirred reactor (WS) model describing such flames. predicted ignition delay lift-off length n-heptane sprays are compared experimental results published within Engine Combustion...

Purpose The purpose of this numerical work is to present and test a new approach for large-scale scalar advection (splicing) in large eddy simulations (LES) that use the linear sub-grid mixing model (LEM) called LES-LEM. Design/methodology/approach splicing strategy based on an ordered flux spliced LEM segments. principle low-flux segments have less momentum than high-flux and, therefore, are displaced This affects order both inflowing outflowing LES cell. implemented pressure-based fluid...

The paper addresses a probabilistic approach to lifetime prediction of cooled gas turbine blades. Variations load and material parameters are taken into account by combination direct Monte Carlo Simulation Response Surface Method. proposed allows reduction in the number finite element analyses especially for problems with low failure probability. Therefore, computational effort becomes acceptable even full-scale 3D 2D analysis models. Results life assessment shown two probability sensitivity...

Simulating practical combustion systems requires the approximation of interaction between turbulence, molecular transport and chemical reactions. Turbulent models are used for this purpose, but their behavior is difficult to anticipate based on mathematical formulations, making use numerical experimentation necessary. Therefore, present work explores effect three turbulent-combustion models, two eddy-viscosity parameters a problem which notoriously model: flame extinction reignition. For...