Entropy variation in isothermal fluid flow considering real gas effects

Entropy generation analysis of non-newtonian fluid in rotational flow

The entropy generation analysis of non-Newtonian fluid in rotational flow between two concentric cylinders is examined when the outer cylinder is fixed and the inner cylinder is revolved with a constant angular speed. The viscosity of non-Newtonian fluid is considered at the same time interdependent on temperature and shear rate. The Nahme law and Carreau equation are used to modeling dependenc...

Numerical network models and entropy principles for isothermal junction flow

We numerically explore network models which are derived for the isothermal Euler equations. Previously we proved the existence and uniqueness of solutions to the generalized Riemann problem at a junction under the conditions of monotone momentum related coupling constant and equal crosssectional areas for all connected pipe sections. In the present paper we extend this proof to the case of pipe...

Entropy Generation Minima in Different Configurations of the Branching of a Fluid-Carrying Pipe in Laminar Isothermal Flow

The paper discusses a simple multi-variable optimization problem: the bifurcation of a branch of a pipe of circular cross-section with a given initial radius r0 and delivering a given mass flow rate m0.The optimization is performed using an objective function that prescribes the minimization of the entropy generation rate due — in this simple case — only to viscous flow effects within the tubes...

Optimal control of non-isothermal viscous fluid flow

Keywords: Optimal control Stokes–Oldroyd model Non-isothermal Viscous flow Four-to-one contraction Finite element method a b s t r a c t For flow inside a four-to-one contraction domain, we minimize the vortex that occurs in the corner region by controlling the heat flux along the corner boundary. The problem of matching a desired temperature along the outflow boundary is also considered. The e...

Effects of Fluid Viscoelasticity in Non-Isothermal Flows