heat exchangers are the critical components of refrigeration and liquefaction processes. selection of appropriate operational conditions for cryogenic recuperative heat exchanger and expansion valve operating in joule-thomson cooling system results in improving the performance and efficiency. in the current study, a straightforward procedure is introduced to design an efficient joule-thomson co...

in this research, the coupling between non-gray radiation and separation convection flow in a duct is investigated numerically. distributions of absorption coefficients across the spectrum  are obtained from the hitran2008 database. the full-spectrum k-distribution method is used to deal with the non-gray part of the problem, while the gray radiation calculations are performed using the planck ...

A new class of helium-cooled high heat-flux plasma facing heat exchanger (HX) concept is presented. These unique “Foam-In-Tube” HX concepts are composed of a thin tungsten shell integrally bonded to an open-cell tungsten foam core. High heat flux tests show maximum heat loads of 22.4 MW/m using 4 MPa helium at a flow rate of 27 g/s. Based on these impressive performance results, a unique and sc...

The forced convection heat transfer in high porosity metal-foam filled tube heat exchangers are studied in this paper. The Brinkman Darcy momentum model and two energy equations for both solid and fluid phases in porous media are employed .The study shows that using metal-foams can significantly improve the heat transfer in heat exchangers. Keywords—metal foam, Nusselt number, heat exchanger, h...

in this paper, the effects of baffle on thermal characteristics of combined convection-radiation heat transfer in laminar flow adjacent to an inclined backward facing step (bfs) in a horizontal duct are investigated. a baffle is mounted on the top wall of channel downstream side of step. in this study, the fluid is treated as a gray, absorbing, emitting and scattering medium; therefore, in the ...

the purpos of this paper is to aim the maximum heat transfer rate in a plate-fin heat exchanger with a constant volume and a contant surface area at a prescribed pressure drop. this paper propose a method for design a plat-fin heat exchanger in which a maximum pressure drop occurs at a constant volume and surface are. in this paper as a case study, a preheater of a gas turbine which is a plate-...

Title of Document: DEVELOPMENT OF MULTI-SCALE, MULTI-PHYSICS, ANALYSIS CAPABILITY AND ITS APPLICATION TO NOVEL HEAT EXCHANGER DESIGN AND OPTIMIZATION Omar Abdelaziz Ahmed Abdelaziz, Doctor of Philosophy, 2009 Directed By: Reinhard Radermacher, Professor Department of Mechanical Engineering Heat exchanger development using enhanced heat transfer surface designs and optimization techniques is a c...

Polymerase chain reaction (PCR) is widely used in biochemical analysis to amplify DNA and RNA in vitro. The PCR process is highly temperature sensitive, and thermal management has an important role in PCR operation in reaching the required temperature set points at each step of the process. The goal of this research is to achieve a thermal technique to rapidly increase the heating/cooling therm...

abstract: in this study, al 2 o 3 /eg and tio 2 /eg nanofluids as coolants have been used in the double-tube heat exchanger. the hot solvent inlet heat exchanger must be cooled down with a specified amount. we can use nanofluids as coolants in the heat exchanger for optimization of the heat transfer area. therefore, the efficacy of nanofluids as coolants is verified. furthermore, flow rate of c...