In this study, the relationship among the concepts of entropy generation rate, entransy theory, and generalized thermal resistance to the optimal design of thermal systems is discussed. The equations of entropy and entransy rates are compared and their implications for optimization of conductive heat transfer are analyzed. The theoretical analyses show that based on entropy generation minimizat...

this paper presents results of a numerical study of mixed convection and entropy generation of cu–water nanofluid in a square ventilating cavity at different inclination angles. except a piece of bottom wall with a uniform heat flux, all of the cavity walls are insulated. the inlet port is placed at the bottom of the left wall and the outlet port is positioned at the top of the right wall. entr...

The heat transfer for a non-Newtonian power-law fluid over a moving surface is investigated by applying a uniform suction/injection velocity profile. The flow is influenced by internal heat generation/absorption. The energy equation is solved at constant surface temperature condition. The Merk-Chao series is applied to obtain a set of ODEs instead of a complicated PDE. The converted ordinary diffe...

Fuel flexibility is a significant advantage of solid oxide fuel cells (SOFCs) and can be attributed to their high operating temperature. The eligibility of a combined heat and power (CHP) system has been investigated as a new power generation methode, in this study. Natural gas fueled SOFC power systems via methane steam reforming (MSR) yield electrical conversion efficiencies exceeding 50% and...

in this paper, convection heat transfer of al2o3-water nanofluid turbulent flow through internally ribbed tubes with different rib shapes (rectangular, trapezoidal and semi-circular) is numerically investigated. for each rib shape, the optimum geometric ratio and volume fraction were calculated using entropy generation minimization technique. the governing equations in steady state and axisymme...

In this study, mixed convection heat transfer and local and global entropy generation in aventilated square cavity have been investigated numerically. The natural convection effect isachieved by a constant heat flux imposed at the bottom wall and cooled by injecting a coldfollow. In order to investigate the effect of port location, four different placementconfigurations of the inlet and outlet ...

The present study carefully examined entropy generation during wustite pellet reduction to sponge iron. The finite volume method was used to solve the governing equations. The grain model was used to simulate the reaction rate. The reactant gases including carbon monoxide and hydrogen were converted to water and carbon dioxide after wustite reduction. Entropy is generated by heat transfer, mass...

in this article effects of friction stir welding (fsw) tool rotational and traverse speeds were studied on heat generation and temperature distribution in welding zone of aa1100 aluminium alloy. computational fluid dynamics method was used to simulate the process with commercial cfd fluent 6.4 package. to enhance the accuracy of simulation in this study, the welding line that is located workpie...