Begell House
Heat Transfer Research
Heat Transfer Research
1064-2285
36
6
2005
Second-Law Analysis of Thermally Developing Forced Convection in a Porous Medium
Entropy generation for thermally developing forced convection in a porous-saturated circular tube of uniform wall temperature is investigated analytically on the basis of the Darcy flow model where the viscous dissipation effects had also been taken into account. A parametric study showed that decreasing the group parameter and the Péclet number increases the entropy generation while for the Brinkman number the converse is true.
Kamel
Hooman
Mechanical Engineering Department, Persian Gulf University, Bushehr 75168, Iran
437-448
Influence of Flow Twisting on Convective Heat Transfer in Banks of Twisted Tubes
The method of artificial turbulization of flow by twisting the latter by twisted tubes allows one to substantially reduce the overall dimensions and mass of heat exchanging apparatuses owing to heat transfer enhancement due to the deformation of the velocity and temperature profiles in the wall layer on twisted tubes and due to the increase in the intensity of heat and mass transfer processes between the wall layer and the flow core in longitudinal flow past banks of twisted tubes. The results of experimental investigations of heat transfer and hydraulic resistance that were obtained by the present author and other research workers for banks of twisted tubes and rods with spiral finning, where the flow structure is close to that in the banks of twisted tubes, are correlated and analyzed.
Boris V.
Dzyubenko
Moscow Aviation Institute (State Technical University), 4 Volokolamskoe Highway, Moscow, 125993, Russia
449-460
Heat Transfer in a Cylindrical Air Gap for Stepwise Heat Release of the Inner Cylinder
Radiative-convective heat transfer in an air gap between the cylindrical surfaces has been studied experimentally. The temperature mode of the upper nonheated unit located on the unit with heat-generating equipment was of interest. Different versions of a sealed system and various degrees of depressurization, including organization of flow-through natural "venting" of the air gap, have been discussed.
Yu. I.
Machuev
OJSC Design Bureau of Special Machine Building, St. Petersburg, Russia
A. M.
Vorobiov
OJSC Design Bureau of Special Machine Building, St. Petersburg, Russia
A. F.
Utkin
OJSC Design Bureau of Special Machine Building, St. Petersburg, Russia
V. G.
Dolbenkov
OJSC Design Bureau of Special Machine Building, St. Petersburg, Russia
461-466
Thermal Radiation of Liquid Metal Alloys
An absolute radiation method was used to measure normal integral emissivities of liquid alloys "bismuth-indium", "bismuth-lead", and "bismuth-tin" at various temperatures and concentrations of metals. The measurement error ranged from ±5% to ±8%. These data have been obtained for the first time. An integrated generalized relationship for calculation of semi-spherical integral thermal radiation fluxes of liquid binary metal alloys has been obtained.
K. B.
Panfilovich
Kazan State Technological University, Kazan, Russia
I. L.
Golubeva
Kazan State Technological University, Kazan, Russia
V. V.
Sagadeev
Kazan State Technological University, Kazan, Russia
467-474
Intensification of Radiative Heat Transfer and Development of New Types of Tube Furnaces
A technology of covering ceramic surfaces and metal pipes with special high-emissivity coatings has been developed in order to intensify radiative heat transfer and create effective tube furnaces for petrochemical processes. Newly designed furnaces with a highly radiative coating ensure a high output of target products and small use of metal.
A. V.
Stepanov
Institute of Bioorganic Chemistry and Petrochemistry, National Academy of Sciences of Ukraine, Ukraine
N. I.
Sulzhik
OJSC "Ukrneftekhimproekt", Ukraine
V. N.
Nikolaenko
OJSC "Ukrneftekhimproekt", Ukraine
475-480
Parametric Identification of Thermophysical Properties of Highly Porous Partially Transparent Materials Based on the Solution of a Two-Dimensional Problem of Radiative-Conductive Heat Transfer
A mathematical formulation of a two-dimensional inverse coefficient-type problem of radiative-conductive heat transfer for parametric identification of thermophysical properties of partially transparent materials is presented. An algorithm for solution of the inverse problem is described. An accuracy of the solution of the inverse problem and its stability to the presence of random errors in the input data is analyzed. The formulation of the problem of optimal planning of temperature measurements for two-dimensional processes of radiative-conductive heat transfer is given; the impact of the parameters of the scheme of experiment on the results of planning is investigated and measurement plans for a series of experimental conditions are given.
P. V.
Prosuntsov
All-Russia Institute of Aviation Materials, Moscow, Russia
481-500
Influence of Radiation from the Flame Torch on Propagation of Steppe Fires
Statement and analytical solution of the problem on propagation of steppe fire, given radiation from the flame torch, are presented.
A. M.
Grishin
Tomsk State University, Tomsk, Russian Federation
D. M.
Burasov
Tomsk State University, Tomsk, Russian Federation
501-506
Influence of Turbulence on Transfer of Thermal Radiation in Hydrogen Diffusion Flames
Quantitative estimates of the inputs by turbulent fluctuations of temperature and concentrations into thermal radiation of the hydrogen diffusion flame have been obtained. Numerical studies have been made using the database on laser flame sounding. The coefficients in the equation of radiation transfer were averaged directly by the samples of instant values of temperature and concentrations, which allowed excluding errors related to the use of model distribution functions. It was shown that processes of turbulence-radiation interaction are one of the major mechanisms of formation of the fields flame thermal radiation.
A. I.
Bril'
B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Minsk, Belarus
507-516
Physical Modeling of Fire Storms
Three independent methods were applied in laboratory conditions to produce fire storms. The similarity criteria of the solved problem, the Grashof and Prandtl numbers and the rotational Froude number have been found. It has been demonstrated that formation of a fire storm does not depend on the ignition source, but is determined by the value of the heat-flux density.
A. M.
Grishin
Tomsk State University, Tomsk, Russian Federation
A. N.
Golovanov
Tomsk State University, Tomsk, Russian Federation
Ya. V.
Sukov
Tomsk State University, Tomsk, Russian Federation
517-527