摘要:

AbstractThe results of an analytical study of bilateral heat transfer to liquid metals flowing turbulently through annuli are reported. The study was based on the assumptions of 1) uniform, though not necessarily equal, heat fluxes from the walls, 2) fully-established temperature and velocity profiles, and 3) no effect of transverse temperature variations on the physical properties of the liquid metal. The fraction,ξ, of the total heat delivered to the flowing stream which comes from the inner wall was varied from zero to unity. Also two special situations were treated: (A) equal heat fluxes from both walls, and (B) uniform but unequal heat fluxes at the walls, with equal wall temperatures at a given axial position along the channel.The results are presented in the form of Nusselt numbers forr2/r1values from 1 to 7, Peclet numbers for 102to 104, andξvalues from 0 to 1.The coefficient for the heat transferred from the inner wall goes to infinity at a certain value ofξ, which depends only on the ratior2/r1. The same thing occurs for the coefficient for the outer walls, except at a different values ofξ.The interesting observation was made that atPe = 6700, the Nusselt numbers for the following situations are all equal to about 35: 1) flow in a pipe, 2) flow between parallel plates with equal heat fluxes from both plates, 3) flow in any annulus with equal heat fluxes from the walls, with reference to the heat transferred from the outer wall, 4) flow in any annulus with a uniform heat flux from each wall and having equal wall temperatures at a given axial position, with reference to the heat transferred from the outer wall.

ISSN:0029-5639    

DOI:10.13182/NSE65-A21018

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

摘要:

AbstractThe perturbation in a thermal neutron spectrum near an absorber immersed in a moderator has been studied using activation techniques. The results show two separate effects for pure thermal spectra, a‘transmission hardening’depending on the energy variation of the absorber cross section and a‘boundary effect’depending on the energy variation of the moderator scattering cross section. These results are in agreement with energy-dependent Milne problem calculations for a mass one, free-gas moderator and with another experimental result when a third‘source hardening’effect in reactor spectra is considered.

ISSN:0029-5639    

DOI:10.13182/NSE65-A21019

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

ISSN:0029-5639    

DOI:10.13182/NSE65-A21020

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

ISSN:0029-5639    

DOI:10.13182/NSE65-A21021

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

ISSN:0029-5639    

DOI:10.13182/NSE65-A21023

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

ISSN:0029-5639    

DOI:10.13182/NSE65-A21024

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

ISSN:0029-5639    

DOI:10.13182/NSE65-A21025

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

ISSN:0029-5639    

DOI:10.13182/NSE65-A21026

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

ISSN:0029-5639    

DOI:10.13182/NSE65-A21027

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor

ISSN:0029-5639    

DOI:10.13182/NSE65-A21029

出版商:Taylor&Francis    

年代:1965

数据来源: Taylor