longitudinal heat conduction is an important parameter in the cryogenic field, especially in cryogenic heat exchangers. in the present work, the parasitic effect of tube wall longitudinal heat conduction on temperature measurement has been studied in cryogenic laminar hydrogen flow. the effects of various parameters such as wall cold end temperature, wall thermal conductivity, gas volumetric fl...

The aim of this paper is to retrieve the temperature-dependent refractive index distribution in parallel-plane semi-transparent media with combined conduction-radiation heat transfer, by measurement exit intensities over boundaries. finite volume method combination discrete ordinates used solve energy equation. results direct solution for both linear-spatially and linear-temperature-dependent d...

The effect of radiation on laminar and turbulent mixed convection heat transfer of a semitransparent medium in a square enclosure was studied numerically using the Finite Volume Method. A structured mesh and the SIMPLE algorithm were utilized to model the governing equations. Turbulence and radiation were modeled with the RNG k-ε model and Discrete Ordinates (DO) model, respectively. For Richar...

The use of natural convection, side-arm heat exchangers in solar domestic water heating systems is becoming a popular method of reducing system cost and electric demand. In this paper, we compare thermal performances of three natural convection heat exchangers mounted along the outside of the water storage tank and a commercial wraparound-tank heat exchanger to two forced-flow heat exchangers. ...

Please cite this article in press as: M. Sankar et a Mass Transfer (2012), http://dx.doi.org/10.1016 Double-diffusive convection in a vertical annulus filled with a fluid-saturated porous medium is numerically investigated with the aim to understand the effects of a discrete source of heat and solute on the fluid flow and heat and mass transfer rates. The porous annulus is subject to heat and m...

Some engineering systems are naturally described by differential-algebraic equations (DAE), whereas it may be difficult or impossible to model them with ordinary differential equations (ODE). This paper proposes an approach to fault diagnosis for systems described by DAEs. Through a particular discretization method and under realistic assumptions, the considered continuous time DAE model is tra...

Customarily, the LMTD correction factor, FT, is used to screen alternative designs for a heat exchanger. Designs with unacceptably low FT values are discarded. In this paper, authors have proposed a more fundamental criterion, based on feasibility of a multipass exchanger as the only criteria, followed by economic optimization. This criterion, coupled with asymptotic energy targets, provide the...