This work presents a numerical analysis of entropy generation in Γ-Shaped enclosure that was submitted to the natural convection process using a simple thermal lattice Boltzmann method (TLBM) with the Boussinesq approximation.  A 2D thermal lattice Boltzmann method with 9 velocities, D2Q9, is used to solve the thermal flow problem. The simulations are performed at a constant Prandtl number (Pr ...

One of entropy’s puzzling aspects is its dimensions of energy/temperature. A review of thermodynamics and statistical mechanics leads to six conclusions: ~1! Entropy’s dimensions are linked to the definition of the Kelvin temperature scale. ~2! Entropy can be defined to be dimensionless when temperature T is defined as an energy ~dubbed tempergy!. ~3! Dimensionless entropy per particle typicall...

The attractor mechanism implies that the supersymmetric black hole near horizon solution is defined in terms of the conserved charges only and therefore is independent of asymptotic moduli. Starting only with the near horizon geometry, Sen’s entropy functional formalism computes the entropy of an extreme black hole by means of a Legendre transformation where the electric fields are defined as c...

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...

In the present study, an unlooped pulating heat pipe has been considered with two liquid slugs and three neighboirng vapor plugs.The governing equations such as momentum, energy and mass equations are solved explicitly except the energy equation of liquid slugs.The aim of the present study is to calculate the entropy generation through the performance of a pulsating heat pipe. Additionally, the...

Analysis of intrinsic irreversibility and heat transfer in a buoyancy-driven changeable viscosity liquid along an incline heated wall with convective cooling taking into consideration the heated isothermal and isoflux wall is investigated. By Newton’s law of cooling, we assumed the free surface exchange heat with environment and fluid viscosity is exponentially dependent on temperature. Appropr...

In order to find more correlations between entropy and other related quantities, an analogical analysis is conducted between thermal science and other branches of physics. Potential energy in various forms is the product of a conserved extensive quantity (for example, mass or electric charge) and an intensive quantity which is its potential (for example, gravitational potential or electrical vo...

Standard entropy calculations in quantum field theory, when applied to a subsystem of definite volume, exhibit area-dependent UV divergences that make a thermodynamic interpretation troublesome. In this paper we define a renormalized entropy which is related with the Newton-Wigner position operator. Accordingly, whenever we trace over a region of space, we trace away degrees of freedom that are...

In this short essay we review the arguments showing that black hole entropy is, at least in part, “entanglement entropy”, i.e., missing information contained in correlations between quantum field fluctuations inside and outside the event horizon. Although the entanglement entropy depends upon the matter field content of the theory, it turns out that so does the Bekenstein-Hawking entropy A/4h̄Gr...

The temperature (T ) and entropy (S) fields of baryonic gas, or intergalactic medium (IGM), in the ΛCDM cosmology are analyzed using simulation samples produced by a hybrid cosmological hydrodynamic/N-body code, effective capturing shocks and complex structures with high precision. We show that in the nonlinear regime the dynamical similarity between the IGM and dark matter will be broken in th...