[en] A mathematical model of radiative heat exchange in the throats of wide-necked helium cryostats is analyzed. A comparison of the numerical results with known calculated and experimental data shows their good agreement

[en] In the development of reactor systems, if cost penalties are not too great, direct testing of reactor components is usually undertaken. When the financial burden of such direct testing becomes too severe, ensuring the adequate performance of reactor components entails the use of proven design methods. The establishment of such methods involves: a) the carrying out of basic generic work to determine the physical phenomena and physical principles involved in component performance. b) the use of this generic data in the generation of mathematical models by means of which reactor situations can be assessed. c) the validation of these models against experimental data (produced at a reasonable cost) in fairly complex situations representative of the reactor configurations. This paper describes the present position, in the UK, in respect of the development of such design methods for the CDFR above sodium environment

[en] This volume provides a source for the great diversity of material contained in the six-volume set of Heat Transfer 1986. It contains abstracts of all invited and general papers presented at the conference

[en] Elementary considerations are used to define and analyze the discrete spectrum for a general radiative transfer model that includes polarization effects. (author)

[en] Two phase heat transfer correlation for the slug to annular flow regimes. Successful design of heat exchanger such as evaporator requires accurate prediction of the local heat transfer coefficient for boiling regime. Investigations of two phase heat transfer in horizontal pipe flow have led to a new correlation for the heat transfer coefficient. The proposed correlation is: Nu_TP=2,90 [Re]^0,82 [Pr]^0,78 [Bo]^0,62. This correlation was tested and experimental data obtained on covering the slug to annular flow regimes. The correlation produces satisfactory results. (author). 7 figs.; 14 refs

[en] Experimental investigations have been made to study the performance of two finned tube-bundle heat exchangers (FORGO type) when wetted by water sprays. The heat exchangers are designed to cool water in a dry cooling tower. The test-elements had a frontal area of 1 m². The water sprays were created by 20 nozzles, 200 mm in front of the heat exchangers. Air velocities at the inlet of the coolers were in the range 0,8 m/s to 12 m/s and initial temperature differences ITD reached 45 degrees C. The test facility was designed to determine the combined latent and sensible heat fluxes in the wetted heat exchanger, the airside pressure drop and the air humidity and temperature at the exchanger inlet and outlet, and to measure the weight of the water wetting the cooler's surface. The sprayed test elements were investigated in different positions, but most of the experiments were carried out in the position with the fins horizontal

[en] Heat transfer from a heated plate to circular air jets issuing from a square array of nozzles is measured by means of an Infrared Scanning Radiometer (IRSR). Experimental tests are performed for different values of jet Reynolds number, nozzle-to-plate distance, nozzle-to-nozzle spacing and nozzle diameter. The two-dimensional character of IRSR and the possibility of processing digital thermal images on a computer allow to obtain surface temperature maps as well as to compute local heat transfer coefficient profiles. (author)

[en] Local heat flux measurements have to be considered when existing computation rules and experimental results do not provide sufficient information about specific heat transfer problems. Based on the experience gained with auxiliary wall heat flux sensors consisting of thermochains, a new heat flux sensor is described, which consists of film resistor thermochains, a new heat flux sensor is described, which consists of film resistor thermometers. (author)

[en] This paper explores the relative contributions of radiative and convective heat transfer to structures (like shipping containers) in large pool fires. Results include measurements of the temperature of two structures (called calorimeters) in the fire, the flames surrounding the calorimeters, the total heat flux to the calorimeters and the radiative component of the heat transfer at a few locations using transpiration radiometers. These measurements will be compared with calculations. Agreement between the measured radiative heat flux and the calculated radiative heat flux is good. The convective contribution was calculated from the total and radiative parts and was found to be about 10-20% of the total

[en] The heat line, as defined by Kimura and Bejan does not involve, explicitly, a reference temperature for the energy converted by the flow. As a result different flow patterns may be obtained for the same physical problem. In this paper the heat function is re-defined and the temperature of the cold wall, in natural convection flow problem inside cavities, is used as reference temperature. The heat function, as defined here, is also written in a generalized coordinate system and is employed to visualize the heat flow in some natural convection problems inside irregular cavities. (author)