The phenomenon of subcooled flow boiling is important in water-cooled nuclear power reactors, since the presence of vapor influences the system reactivity. ... in reactor safety analyses to investigate low-pressure subcooled boiling (1 to 10 ...
In this paper a convective flow boiling of refrigerant R-113 in a vertical annular channel has ..... The variables f, Na and hQ are also calculated from empirical or ...
May 8, 2012 - The commercial CFD software STAR-CCM+ v6.06 [3] was used in this study. The rod bundle with all the spacers was modeled explicitly using ...
... CHF in thin rectangular channels under low flow (up and down) and low pressure conditions. DISTRIBUTION OF THIS DOCUMENT IS UNLIMITED. MASTER ...
otai parameter with respect to 2W or A. Non-dimensional parameter with respect to S. INTRODUCTION. Critical heat flux (CHF) correlations developed for.
Dec 8, 1999 - Also, the use of the condensate flow rate to determine the overall heat transfer to the massecuite in the experiments is open to question, since it.
Lookup tables (LUTs) have been used widely for the prediction of critical heat flux (CHF) and film-boiling heat transfer for water-cooled tubes. LUTs are basically.
horizontal cylinder in water (dealt with non-wetting liquid here) or highly wetting liquid such as FC-72 due to. The pool boiling CHFs .... Slide Rheostat. â16.
Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/fld. High-Order .... used in product design in aerospace, automotive, micro-electronics, and many other industries. .... It is of course much easier to demonstrate ...
boiling is a well-developed research subject, flow boil- ing in microchannels, not to mention instabilities which occur in these microchannels, have not been ...
CHF from short heaters, using an apparatus that lends itself better to ..... An O-ring was pressed between the base of each heater assem- bly and the flow ...
(2015b) applied LES to study the condensation behavior of isolated vapor bubble in .... model to study bubble dynamics in a nucleate flow boiling using. DNS for ...
Nuclear Engineering and Design journal homepage: www.elsevier.com/locate/nucengdes. Pool boiling CHF enhancement by graphene-oxide nanofluid under ...
contact angle of 45 deg⦠and Kutateladze correlation with Lien- hard and Dhir ..... 38 Duke, E. E., and Schrock, V. E., 1961, Fluid Mechanics Heat Transfer Insti-.
Oct 12, 2014 - boiling during subcooled developing flow of R-11 within vertical annulus ... Abstract In this paper a convective flow boiling of refrigerant R-11 in a .... stop condensing. The interfacial ..... Bergles and Rohsenow (from Collier 1981)
Ecole Polytechnique Universitaire de Marseille : Laboratoire I.U.S.T.I. U.M.R. 6595. Technopôle de Château Gombert - 5, Rue Enrico Fermi - 13453 Marseille ...
Mar 20, 2018 - pressure channels and the downward flow condensation of mix- tures in ... heat transfer process is driven by the convective boiling, and the.
because of break-up and condensation when they are exposed to the lower ... OSV: onset of significant void; ONB: onset of nucleate boiling. Promtong et al. 241 ...
during flow boiling for two refrigerants R134a and R1234yf. ... studied the boiling heat transfer of the refrigerant R1234yf flowing in a ..... several variables.
Sep 26, 2015 - Introduction. The application of flow boiling in microchannels as a cooling ...... less number called convective-confinement number Bd0.5 Ð Relo. ..... rectangular tubes during condensation of refrigerant R134a, Int. J. Refrig 26.
conducted. Flow patterns, temperature and pressure fields of the ... cooling method are demanded. Due to the harsh ... under normal or micro gravity has attracted many attentions and has .... mm ID micro-channel heated uniformly with a working fluid
Kate Gleason College of Engineering,. Rochester Institute ... ing automotive and stationary fuel cells as well as electronics cooling. However, there ..... In addition, they also saw a high heat transfer coefficient near the ONB point ob- ..... 49 St
Aug 22, 2013 - 3.3.2. Quality calculation. The inlet quality of the test section was calculated by the inlet enthalpy and inlet pressure using Nist-refprop (National.
techniques of Real Time Neutron Radiography (RTNR) and ultra-high speed x-ray. Computed ... The heat transfer and pressure drop behavior in two-phase flow boiling is highly ... During operation, x-ray tubes 180 degrees apart fire simultaneously to ..
Alexandria University (EGYPT) for both Bsc and Msc degrees. He got his PhD degree on a common project and common supervision between MIT (USA) and.
Trusted predictions of critical heat flux (CHF) value are essential for safe operation of boilers, steam generators and nuclear power reactors. Prediction techniques are numerous but they are mostly limited to uniformly heated tubes. There are separated effects on CHF, such as axial and radial heat flux distributions that have not been taken much attention. These effects are encountered during operation of boilers/ steam generators and nuclear reactors. The present work is aimed at providing detailed analysis for experimental and numerical techniques used in CHF predictions focusing on non-uniform axial and circumferential heating profiles. For this purpose, heat transfer characteristics in case of CHF and heat transfer and wall boiling modeling are also clearly described.Due to new challenges presented by the non-uniform heating in axial and circumferential directions, research work pertaining to analysis of CHF predictions in real systems for non-uniform heating profiles in both axial and circumferential directions is also presented.
Medhat Nemitallah
Medhat Nemitallah Dr. Medhat A. Nemitallah was graduated from Alexandria University (EGYPT) for both Bsc and Msc degrees. He got his PhD degree on a common project and common supervision between MIT (USA) and KFUPM (KSA). He also worked as a post-doctor trainer at MIT and as an assistant professor at KFUPM. He is specialized in combustion and energy technologies.
978-3-659-59662-9
Current status of CHF and flow boiling CFD predictions techniques
