ABSTRACT A mathematical and numerical model for the treatment of conjugate fluid flow heat transfer problems in domains containing pure fluid, porous, solid regions is presented. The general physically reasoned, allows local thermal nonequilibrium porous region. developed implementation on a simple collocated finite-volume grid. Special attention given to matching interfacial flux, approximation advected variables at interface between regions, pressure–velocity coupling such an interface,...

Abstract A unit-cube geometry model is proposed to characterize the internal structure of porous carbon foam. The based on interconnected sphere-centered cubes, where spheres represent fluid or void phase. used derive all geometric parameters required calculate heat transfer and flow through An expression for effective thermal conductivity derived geometry. Validations show that gives excellent predictions as a function porosity. When combined with existing expressions pore-level Nusselt...

The study of pulsatile flow in stenosed vessels is particular importance because its significance relation to blood human pathophysiology. To date, however, there have been few comprehensive publications detailing systematic numerical simulations turbulent through stenotic tubes evaluated against comparable experiments. In this paper, two-equation turbulence modeling has explored for sinusoidally 75% and 90% area reduction vessels, which undergoes a transition from laminar as well...

The amount of non-revenue water is around 126 billion cubic meters annually worldwide mostly due to leakage. A more efficient wastewater management strategy would use a parametric design for on-demand customized pipe fittings, following the principles distributed manufacturing. To fulfill this need, study introduces an open-source 3D printable easy connect fitting that offers compatibility with different dimensions and materials pipes available in market. Custom fittings were printed using...

The amount of non-revenue water, mostly due to leakage, is around 126 billion cubic meters annually worldwide. A more efficient wastewater management strategy would use a parametric design for on-demand, customized pipe fittings, following the principles distributed manufacturing. To fulfill this need, study introduces an open-source 3D-printable easy-connect fitting that offers compatibility with different dimensions and materials pipes available on market. Custom fittings were 3D printed...

Abstract A numerical study has been undertaken to explore the details of forced convection heat transfer in finned aluminum foam sinks. Calculations are made using a finite-volume computational fluid dynamics (CFD) code that solves for flow and conjugate fluid/porous/solid domains. The results indicate unfinned blocks porous low convective due relatively effective thermal conductivity aluminum. addition fins sink significantly enhances with only moderate pressure drop penalty. enhancement is...

A numerical and experimental investigation of free convection from vertical, isothermal, parallel-walled channels has been undertaken to explore the heat transfer enhancement obtained by adding adiabatic extensions various sizes shapes. Investigations were carried out for air (Pr= 0.7) over a wide range wall heating conditions. In all cases, able increase transfer. The varied 2.5 at low Ra* 1.5 high Ra*. results are in excellent agreement. single correlation accounting channel aspect ratio...

Experiments and computations are presented to quantify the convective heat transfer hydraulic loss that is obtained by forcing water through blocks of graphitic foam (GF) heated from one side. have been conducted in a small-scale tunnel instrumented measure pressure drop temperature rise passing base flux into block. The experimental data were then used calibrate thermal non-equilibrium finite-volume model facilitate comparisons between GF aluminum foam. Comparisons indicate both normal...

Experiments are presented to quantify the convective heat transfer and hydrodynamic loss that is obtained by forcing water through blocks of porous carbon foam (PCF) heated from one side. The experiments were conducted in a small-scale tunnel instrumented measure pressure drop temperature rise passing base flux into block. In comparison similar porosity aluminum foam, present results indicate across higher due large associated with cell windows connecting pores, but performance suggests...

The presented study examines the energetics of confined fluid flow in a rotating reference frame. Parallels are drawn to corresponding scenario rectilinear motion, where ejection results linear propulsion Absorption energy into frame motion leads cooling ejected fluid. Relevance observed temperature separation phenomenon Ranque-Hilsch vortex tubes is discussed.

To simulate the heat transfer performance of devices incorporating high-conductivity porous materials, it is necessary to determine relevant effective properties close volume-averaged momentum and energy equations. In this work, we these by conducting direct simulations in an idealized spherical void phase geometry use results establish closure relations be employed a framework. equation, permeability as defined Darcy’s law well non-Darcy term, which characterizes departure from at higher...

Abstract A numerical model for computing fluid flow and heat transfer, under the assumption of local thermal nonequilibrium, is proposed use with general unstructured, nonorthogonal grids. This introduces novel interface conditions which are physically-reasoned ensure strong coupling between pressure velocity fields. Special attention given to approximation diffusive advective fluxes, forces in momentum equations, pressure–velocity coupling, gradient reconstruction at interfaces while...