نتایج جستجو برای: scale correction term underestimates heat transfer levels

تعداد نتایج: 2490049  

Journal: :مکانیک سیالات و آیرودینامیک 0
یاسر جعفری محمد طیبی رهنی آرمن آدامیان

natural convective heat transfer of nano-fluid in porous media is present in many advanced engineering applications. in this work, this problem has been computationally simulated, using lbm. the configuration used includes a cold exterior region and hot interior cylinders with one-, two-, or three-cylinder arrangements. however, the effective area for heat transfer has been kept the same for al...

Journal: :The Annals of occupational hygiene 2004
Carl J Sennbro Jenny Ekman Christian H Lindh Hans Welinder Bo A G Jönsson Håkan Tinnerberg

Isocyanates may be harmful to workers and methods for monitoring air exposure in the field are necessary. The main aim of this study was to study the field performance of a method using 1-(2-methoxyphenyl)piperazine (2MP)-impregnated filters, by side-by-side comparison of long-term sampling with consecutive short-term samplings and also by short-term comparisons with other methods. Apart from u...

Arman Rokhzadi Mehrdad Raisee Dehkordi

Roughness elements or turbulence promoters have been widely used to enhance heat transfer in cooling passages of modern gas turbine blades. Although such ribs substantially enhance heat transfer, the heat transfer coefficient is reduced immediately at corner downstream of each rib, creating hot spots. To remove such hot spots some of the ribs can be detached from the channel walls. In this pape...

Journal: :international journal of environmental research 2013
m.h. mokhtari b. ahmad h. hoveidi i. busu

metric (mapping evapotranspiration at high resolution with internalized calibration) is known as an appropriate surface energy balance model for the estimation of the spatial distribution of evapotranspiration (et) in semi-arid regions. based on lysimeter measurements, metric has shown et estimates of 10% on a sub-field scale on a daily basis. there is a need to identify how the model is sensit...

Nucleate boiling heat transfer coefficients may be strongly reduced by scale formation, even for conditions where the bulk foulant concentration is well below the saturation concentration. Due to the mechanism of micro-layer evaporation, the local concentration at the heat transfer surface can be considerably increased, causing the formation of scale and changes in bubble frequency and bubble d...

2010
Earl E. Davis Andrew T. Fisher

8 Definitions 9 Heat flow. The rate of thermal energy transfer in a medium 10 driven either conductively along a thermal gradient or 11 advectively via mass transport. The standard unit is 12 watts, W. The term is also used to describe a subdiscipline 13 of geophysics, as in the title of this entry. 14 Conductive heat flux. The heat flow per unit area diffusing 15 by conduction along a thermal ...

Journal: :transport phenomena in nano and micro scales 2014
h. khorasanizadeh m. m. fakhari s. p. ghaffari

in this study, the natural convection heat transfer of variable properties al2o3-eg-water nanofluid in a differentially heated rectangular cavity has been investigated numerically. the governing equations, for a newtonian fluid, have been solved numerically with a finite volume approach. the influences of the pertinent parameters such as ra in the range of 103-107 and volume fraction of nanopar...

Journal: :مهندسی بیوسیستم ایران 0
محمد اسماعیل خراسانی فردوانی رضا علیمردانی محمود امید

this study involved the development and evaluation of a new filtering technique, as based on adaptive free mass load cell. the technique's application in reduction of vibration and impulse noise (commonly added to the sugar cane harvester yield monitoring signals) was tested. this technique is based upon assimilate spring- mass vibration system of weighing scale with a free mass load cell ...

Journal: :journal of computational & applied research in mechanical engineering (jcarme) 2014
m. rahimi m. mortazaei

jet impingement heat transfer is an effective and practical approach that is employed in many industrial processes where heating, cooling, or drying is required. details of the heat or mass transfer rate have been investigated both experimentally and numerically and can be found in the published literature. in most of the numerical studies, control-volume approach has been employed to solve the...

Journal: :energy equipment and systems 2013
farzad bazdidi-tehrani; h. foroutan; m. rajabi-zargarabadi

the present article focuses on the evaluation of a first-moment closure model applicable to film cooling flow and heat transfer computations. the present first-moment closure model consists of a higher level of turbulent heat flux modeling in which two additional transport equations for temperature variance kθ and its dissipation rate εθ are considered. it not only employs a time scale that is ...

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