Search results for "Internal flow"

showing 5 items of 5 documents

A vorticity based aeroacoustic prediction for the noise emission of a low-speed turbulent internal flow

2003

Abstract Turbulent internal flows are known to generate intense noise as well as surface pressure fluctuations. Numerically predicting the noise emission near the prescribed boundaries requires that the sound-generating turbulent flow be adequately represented and described. The k – e method provides a promising tool for obtaining the unsteady characteristics of a realistic turbulent flow interacting with a rectangular flat plate undergoing “ground effect”. The far-field acoustic calculation is facilitated by the Kambe model (from Lighthill’s theory) and an original post-processor has been developed to determine the far-field spectra and the source term characteristics. In pre-processed tur…

Physics::Fluid DynamicsPhysicsGeneral Computer ScienceGround effect (cars)TurbulenceK-epsilon turbulence modelInternal flowComputationGeneral EngineeringEnclosureAeroacousticsMechanicsVorticityComputers & Fluids
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Particle transport in recirculated liquid metal flows

2008

PurposeAims to present recent activities in numerical modeling of turbulent transport processes in induction crucible furnace.Design/methodology/approach3D large eddy simulation (LES) method was applied for fluid flow modeling in a cylindrical container and transport of 30,000 particles was investigated with Lagrangian approach.FindingsParticle accumulation near the side crucible boundary is determined mainly by the ρp/ρ ratio and according to the presented results. Particle settling velocity is of the same order as characteristic melt flow velocity. Particle concentration homogenization time depends on the internal flow regime. Separate particle tracks introduce very intensive mass exchang…

Liquid metalMaterials scienceFurnacesDewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und MaschinenbauMechanical engineeringHomogenization (chemistry)ModellingPhysics::Fluid DynamicsSettlingRecirculated liquid metal flowsFluid dynamicsddc:510Electrical and Electronic EngineeringCrucible furnacesMelt flow indexTurbulent transport processesInternal flowTurbulenceApplied MathematicsLarge eddy simulationParticle physicsMechanicsComputer simulationDewey Decimal Classification::500 | Naturwissenschaften::510 | MathematikComputer Science ApplicationsComputational Theory and Mathematicsddc:620SimulationLiquid metalsNumerical analysisParticles (particulate matter)Large eddy simulationCOMPEL - The international journal for computation and mathematics in electrical and electronic engineering
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Controlling melt convection—an innovation potential for concerted microstructure evolution of Nd-Fe-B alloys

2005

The solidification process and the resulting microstructure of Nd-Fe-B alloys in consideration of melt convection has been investigated experimentally with a specially designed forced crucible rotation technique. Samples were subjected to well-defined forced rotation and vibration, respectively, during induction heating and solidification. A concerted microstructure evolution is possible by enhancement or suppression of the melt convection. As a result, the microstructure pattern, mainly the volume fraction of the soft magnetic a-Fe phase, vary strongly with the strength of the internal flow motion. A distinct reduction of the a-Fe volume fraction in samples with strong melt rotation was ob…

ConvectionInduction heatingMaterials scienceCondensed matter physicsInternal flowMechanical EngineeringMetallurgyCrucibleCondensed Matter PhysicsMicrostructureMagnetic fieldPhysics::Fluid DynamicsMechanics of MaterialsVolume fractionGeneral Materials ScienceMelt flow indexMaterials Science and Engineering: A
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Numerical Simulation as a Tool for Design Optimization of Two-Phase Swirl Flow Atomizers

2021

This study aims to analyze the hydrodynamics in two-phase swirl flow conical atomizers. The Euler-Euler model was used for the calculations. Numerical simulations were performed to provide information about the fluid velocity distribution and the atomizer’s internal flow. The numerical calculations confirmed the experimental data. This data was found based on the consistency of the spray angles obtained by both methods. Assuming the correctness of the numerical simulations performed, they can be treated as a tool for further analysis of mass and energy exchange along with the atomizer and optimizing the atomizer’s design depending on the requirements. The influence of the swirl chamber geom…

Materials scienceEulerian modelComputer simulationInternal flowFlow (psychology)Phase (waves)Chamber geometrySwirl chamberConical surfaceMechanicsPhysics::Fluid DynamicsFlow velocityConical two-phase atomizersEnergy exchange
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On thermoeconomics of energy systems at variable load conditions: integrated optimization of plant design and operation

2007

Abstract Thermoeconomics has been assuming a growing role among the disciplines oriented to the analysis of energy systems, its different methodologies allowing solution of problems in the fields of cost accounting, plant design optimisation and diagnostic of malfunctions. However, the thermoeconomic methodologies as such are particularly appropriate to analyse large industrial systems at steady or quasi-steady operation, but they can be hardly applied to small to medium scale units operating in unsteady conditions to cover a variable energy demand. In this paper, the fundamentals of thermoeconomics for systems operated at variable load are discussed, examining the cost formation process an…

ExergyEngineeringPrimary energyRenewable Energy Sustainability and the Environmentbusiness.industryThermoeconomics has been assuming a growing role among the disciplines oriented to the analysis of energy systems its different methodologies allowing solution of problems in the fields of cost accounting plant design optimisation and diagnostic of malfunctions. However the thermoeconomic methodologies as such are particularly appropriate to analyse large industrial systems at steady or quasisteady operation but they can be hardly applied to small to medium scale units operating in unsteady conditions to cover a variable energy demand. In this paper the fundamentals of thermoeconomics for systems operated at variable load are discussed examining the cost formation process and separately the cost fractions related to capital depreciation (which require additional distinctions with respect to plants in steady operation) and to exergy consumption. The relevant effects of the efficiency penalty due to off design operation on the exergetic cost of internal flows are also examined. An original algorithm is proposed for the integrated optimization of plant design and operation based on an analytical solution by the Lagrange multipliers method and on a multi-objective decision function expressed either in terms of net cash flow or primary energy saving. The method is suitable for application in complex energy systems such as ‘‘facilities of components of a same product’’ connected to external networks for power or heat distribution. For demonstrative purposes the proposed thermoeconomically aided optimization is performed for a grid connected trigeneration system to be installed in a large hotel.Energy Engineering and Power TechnologyCost accountingThermoeconomicsGridEnergy conservationVariable (computer science)symbols.namesakeFuel TechnologyNuclear Energy and EngineeringLagrange multipliersymbolsProcess engineeringbusinessSimulation
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