Search results for " analytical solution"

showing 2 items of 12 documents

AN ANALYTICAL SOLUTION OF KINEMATIC WAVE EQUATIONS FOR OVERLAND FLOW UNDER GREEN-AMPT INFILTRATION

2010

This paper deals with the analytical solution of kinematic wave equations for overland flow occurring in an infiltrating hillslope. The infiltration process is described by the Green-Ampt model. The solution is derived only for the case of an intermediate flow regime between laminar and turbulent ones. A transitional regime can be considered a reliable flow condition when, to the laminar overland flow, is also associated the effect of the additional resistance due to raindrop impact. With reference to the simple case of an impervious hillslope, a comparison was carried out between the present solution and the non-linear storage model. Some applications of the present solution were performed…

Mathematical modelTurbulenceMechanical Engineeringlcsh:SBioengineeringLaminar flowMechanicslcsh:S1-972Industrial and Manufacturing EngineeringKinematic wavePhysics::Fluid Dynamicslcsh:AgricultureInfiltration (hydrology)hydrologic response infiltration analytical solution kinematic wave equationsImpervious surfaceGeotechnical engineeringlcsh:Agriculture (General)Surface runoffGeologyJournal of Agricultural Engineering
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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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