The influence of thermal boundary conditions on turbulent forced convection pipe flow at two Prandtl numbers
نویسندگان
چکیده
منابع مشابه
Turbulent pipe flow at extreme Reynolds numbers.
Both the inherent intractability and complex beauty of turbulence reside in its large range of physical and temporal scales. This range of scales is captured by the Reynolds number, which in nature and in many engineering applications can be as large as 10(5)-10(6). Here, we report turbulence measurements over an unprecedented range of Reynolds numbers using a unique combination of a high-press...
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The method of matched asymptotic expansions, which has been used in previous studies of steady natural convection flow, is extended here to transient natural convection flow at high Prandtl number (Pr). Second-order expansion solutions, valid for large Prandtl numbers, are presented for the transient natural convection flow near a vertical surface which undergoes a step change in temperature. T...
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The Rayleigh-Bénard theory by Grossmann and Lohse [J. Fluid Mech. 407, 27 (2000)] is extended towards very large Prandtl numbers Pr. The Nusselt number Nu is found here to be independent of Pr. However, for fixed Rayleigh numbers Ra a maximum in the Nu(Pr) dependence is predicted. We moreover offer the full functional dependences of Nu(Ra,Pr) and Re(Ra,Pr) within this extended theory, rather th...
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متن کاملNatural Convection at Different Prandtl Numbers in Rectangular Cavities with a Fin on the Cold Wall
The natural convection in differentially heated rectangular cavities with a fin attached to the cold wall was investigated numerically. The top and the bottom horizontal walls of the cavities were insulated while their left and the right vertical walls were maintained at a constant temperature Th and Tc, respectively with Th > Tc. The governing equations written in terms of the primitive variab...
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ژورنال
عنوان ژورنال: International Journal of Heat and Mass Transfer
سال: 2019
ISSN: 0017-9310
DOI: 10.1016/j.ijheatmasstransfer.2019.118601