Special features of generalization of problems in heat transfer under conditions of heat protection of high-temperature firing walls by way of tangential injection

In the presence of additional heating of the wall to be protected by means of radiation heat flux, where the surface temperature may significantly exceed the temperature of coolant being injected, the temperature distribution in the wall zone of mixing of the main and injection flows becomes nonmonotonic. As a result, the Reynolds analogy is violated, i.e., the profiles of dimensionless temperature at the firing wall turn out to be dissimilar with the velocity profiles. In view of this, it is suggested to use the method of characteristic scales for generalizing the results of calculation of motion of ideal incompressible gas with due regard for the temperature dependence of the properties and for heat transfer under conditions of tangential injection on a high-temperature wall (in particular, at T _w s>T _ad ). The respective scales and the dimensionless form of equations are obtained for the problem under consideration. It is demonstrated that, in the case of tangential injection, strict similarity exists of velocity fields in turbulent flow, as well as of temperature fields for physically dissimilar liquids.     

Special features of the processes of heat and mass transfer under a shelf glacier

The reaction of a shelf glacier to possible changes in the global temperature of the ocean is studied. A two-dimensional model of the thermohaline circulation of water under a shelf glacier that is determined by heat and mass transfer on the boundary of the ocean and the glacier is considered. The velocity of the front of the phase transition “glacier-water” is evaluated, and the effect of different boundary conditions on the velocity is studied. Melting/building-up of ice on the lower boundary of a shelf glacier is an integral response to a change in the temperature of the water, and it can be a characteristic of the global change in the temperature of the ocean.     

Influence of ultrasound on heat transfer under the conditions of forced flow of a high-temperature melt

The influence of elastic oscillations at a frequency of 20 kHz on the heat transfer associated with the forced flow of a high-temperature melt in a tube is investigated experimentally. It is shown that the heat-transfer coefficient can be as much as doubled.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 48, No. 2, pp. 322–325, February, 1985.     

Combined heat transfer under conditions of free convection

On the basis of the boundary-layer equations solutions are obtained for the problems of convective and combined heat transfer under conditions of free convection in transparent and gray media. The solution for convective heat transfer in a transparent medium is obtained by means of a Taylor expansion of the temperature function. Expressions for the radiative and convective components of combined heat transfer are also presented, and it is shown that these fluxes are interrelated quantities.     

Special features of heat transfer in carbo- and glass-fiber materials at low temperatures

The article presents the results of the experimental investigation of the thermo-physical properties of composite polymer materials in the low-temperature region.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 39, No. 6, pp. 1061–1065, December, 1980.     

Characteristics of heat transfer in the region of gas injection into a supersonic high-temperature gas stream

An experimental study was made of the heat transfer distribution during gas injection into the supersonic region of a Laval nozzle. The dimensionless parameters governing this process have been established as a result.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 24, No. 5, pp. 790–797, May, 1973.     

Numerical investigation of heat transfer under laminarization conditions of turbulent flows

Based on the mathematical boundary layer model, a numerical investigation of heat transfer is carried out for a wide range of turbulent Reynolds numbers in nozzles of experimental devices under laminarization conditions of turbulent flows.Translated from Inzhenerno-fizicheskii Zhurnal, Vol. 61, No. 2, pp. 223–229, August, 1991.     

Special features of flow and heat transfer in staggered bundles of transversely finned tubes

The special features of flow and heat transfer in staggered bundles of tubes with external circular fins are investigated in a wide range of their geometrical characteristics.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 60, No. 6, pp. 895–902, June, 1991.     

Analytic investigation of heat and mass transfer under varied drying conditions

Formulas are obtained for heat and mass flows at the boundary of the semispace during the second drying period with the temperature and mass-transfer potential remaining constant at that boundary.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 30, No. 6, pp. 1075–1080, June, 1976.     

Subcooled liquid boiling heat transfer under conditions of stepwise heat-load release

The results of experimental investigations of the effect of liquid subcooling below the saturation temperature on boiling heat transfer under conditions of an increase in a heating load are presented. Water and TS-1 kerosene were used as heat carriers. The obtained experimental data on subcooled liquid boiling heat transfer has been generalized by an empirical relation. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 80, No. 1, pp. 136–139, January–February, 2007.     

Experimental investigation of heat transfer under conditions of laminarization of turbulent flows

The results of an experimental investigation of the temperature in model nozzles of an experimental setup under conditions of laminarization of turbulent flows are presented.Translated from Inzhenerno-fizicheskii Zhurnal, Vol. 60, No. 2, pp. 181–185, February, 1991.     

Temperature stresses in a cylinder in heat resistance tests under conditions of variable heat transfer

The temperature field of a cylinder cooled (heated) in liquid media is numerically determined with allowance for the temperature dependence of the heat transfer coefficient. The results obtained are compared with calculations for =const. Nonomgrams are given for calculating the maximum thermal stresses in the case of a linear dependence of heat transfer coefficient on temperature.     

Applicability of boundary-layer theory to calculation of heat transfer under separation conditions

The conditions are examined under which methods and relations developed for attachment flow are applicable to regions of separation flow.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 43, No. 3, pp. 397–401, September, 1982.     

层流状态下纳米流体的对流传热特性

通过数值模拟的方法研究了层流状态下雷诺数、体积分数、颗粒和基液种类以及颗粒粒径对纳米流体对流传热特性的影响。研究结果表明,纳米流体的对流传热系数明显高于基液,并且与基液和颗粒的性质、颗粒的体积分数及颗粒粒径密切相关。纳米流体的对流传热系数随着颗粒和基液热导率的增加、颗粒体积分数的增加以及颗粒粒径的减小而增大。研究发现,对于一定体积分数的Cu-水纳米流体,在层流状态下对流传热系数的提高程度基本保持一致,与雷诺数大小无关。     

Corrosion of M1 copper in an aqueous ethylene-glycol heat carrier under conditions of heat transfer

We have proposed an equation for calculating the mean temperature of the wall of a copper channel depending on the heat-flux density and solution velocity in the channel. We have assumed that the formation of corrosion products on copper and in the solution includes reactions leading to the appearance of complex compounds of copper with components of the solution as well as of solvated and desolvated oxides, and the shift of dynamic equilibrium in these reactions depends on the temperature of the copper surface. Under conditions of the ion-exchange purification of 66% ethylene-glycol solution, the coefficient of protective action (Z) decreases with increase in the heat-flux density and the corresponding growth of the temperature of the copper surface. A decrease in the rate of copper dissolution (Z > 40%) can be reached in 66% ethylene-glycol solution with a specific electric resistance of 25 kΩ·m and a concentration of dissolved oxygen of 0.9–1 g/m³. __________ Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 41, No. 5, pp. 41–48, September–October, 2005.     

Radiative-conductive heat transfer under conditions of a regular mode of the first kind

The regularities of heating a plane layer of a semitransparent condensed medium with optically smooth surfaces are analyzed under the conditions of a regular mode of the first kind.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 36, No. 3, pp. 449–453, March, 1979.     

Influence of cooling conditions on the local parameters of heat and mass transfer in condensation heat-utilization units

Based on the earlier developed model of calculation of the local parameters of heat and mass transfer in deep cooling of flue gases (a vapor-gas mixture) in a bundle of tubes of a condensation heat-utilization unit, the distribution of the parameters of a condensing vapor-gas mixture both along the length of the tubes and in the depth of the tube bundle in a crossflow under various cooling conditions corresponding to the working parameters of heat-utilization units at industrial thermoelectric plants (TEP) and in boiler houses has been obtained. A comparison of the calculated values of the heating efficiency of the indicated heat-utilization unit with the results of tests of the condensation heat-utilization unit at the Ul’yanovsk TEP-3 (Russia) has demonstrated their satisfactory agreement.     

Heat transfer characteristics of spirally-coiled circular fin-tube heat exchangers operating under frosting conditions

The objective of this study is to investigate the heat transfer characteristics of spirally-coiled circular fin-tube heat exchangers under frosting conditions. The heat transfer rate, pressure drop, frost thickness, and Nusselt number of the heat exchanger were measured and analyzed by varying the fin pitch and number of tube rows under frosting conditions. In addition, the Nusselt number of the spirally-coiled circular fin-tube exchanger was compared with those of flat plate fin-tube heat exchangers with discrete fins. An empirical correlation of the Nusselt number was developed as a function of the Reynolds number, dimensionless fin pitch normalized by the hydraulic diameter, i.e., D_h/F_p, Fourier number, and number of tube rows. The measured Nusselt number was consistent with the predicted value with mean and average deviations of 3.5% and 0.3%, respectively.     

Heat transfer characteristics of accumulator heat exchangers under various geometric and operating conditions

To minimize the possibility of flash gas generation at the inlet of the expansion device in multi air-conditioners, an accumulator heat exchanger is usually adopted. In this study, the heat transfer rate and subcooling difference in an accumulator heat exchanger were measured under various operating and geometric conditions. The effect of the operating conditions on the performance of the accumulator heat exchanger was analyzed for R-22, R-134a, and R-410A. The performance of the accumulator heat exchanger was also analyzed by varying diverse geometric parameters: the inner volume and the ratio of the diameter to height of the accumulator, and the diameter, length, and bending diameter of the inner heat exchanger. In addition, the flow of the refrigerant-oil mixture inside the accumulator was visualized. Based on the measured data, a dimensionless correlation for predicting the subcooling difference across the accumulator heat exchanger was developed.