this work presents the heat transfer characteristics of a new type of porous radiant air heater that operates on the basis of effective energy conversion method between flowing gas enthalpy and thermal radiation. at each layer, the gas and solid phases are considered in non-local thermal equilibrium, and combustion in the porous radiant burner is modeled by considering a non-uniform heat genera...

Based on an effective energy conversion method between gas enthalpy and thermal radiation, a multi-layered type of porous air heater has been proposed. In the five layered structure which is analyzed in this work, there are five porous layers which are separated by four quartz glass windows. The main layer operates as a porous radiant burner that products a large amount of thermal radiative ene...

In this paper double flow packed bed solar air heater has been investigated theoretically. The effect of air mass flow rate, porosity and different depth ratios at study state conditions on the thermal performance of a double flow packed bed solar air heater is found by using the alternative simulation system. Comparisons between the measured thermal and effective thermal efficiency of the doub...

OBJECTIVE To compare the efficacy of forced-air warmers and radiant heaters on rewarming after cardiac surgery in a prospective randomized study. METHODS Fifty male patients who had undergone coronary artery bypass graft surgery were studied. The control group (Gr. C, n=10) was nursed under a standard hospital blanket. Two groups were treated with forced-air warmers: WarmTouch 5700 (Gr. WT, n...

It can be very challenging to recover explosives traces from porous surfaces, such as clothing and car seats, compared to non-porous surfaces. The contact heater has been developed as a novel instrument designed to recover explosives traces from porous surfaces. Samples are taken by heating and drawing air across a surface, with the air flowing through a sampling cartridge containing adsorbent ...

In this study an experimental work was performed to examine the effect of porous media on the heat transfer from a cylindrical heater in the case of steady-state forced convection. Porous media consisted of Spherical glasses of diameter 0.6 cm and air was used as the cooling fluid. The bulk temperature was approximated by the inlet temperature and Properties of the air were found at the film te...

The objective of this study is to determine the most energy efficient and cost effective combination of architectural elements and mechanical systems to specify in an office building while maintaining a comfortable and healthy indoor environment for the occupants. A commercial office building located in the Minneapolis area with three heating, ventilating, and air-conditioning (HVAC) systems an...

AIMS To test the hypothesis that external radiant heating might lead to significant fluctuations in superficial and core head temperatures in newborn infants. METHODS In an observation group of 14 term infants nursed under a radiant heater, servo-controlled to the abdominal skin, changes in rectal, core head, and scalp temperatures with heater activation were examined. In a further interventi...

The goal of the inverse analysis is to find a set of heaters over some parts of boundary, called the heater surface, to satisfy the desired heat flux profile over the design surface. Micro-genetic algorithm is employed to inverse design of a radiant enclosure with absorbing-emitting medium. The direct problem of radiative heat transfer is solved by the discrete transfer method. The inverse prob...

This paper describes a theoretical study to investigate the heat transfer characteristics of porous radiant burners. A one dimensional model is used to solve the governing equations for porous medium and gas flow before the premixed flame to the exhaust gas. Combustion in the porous medium is modeled as a spatially dependent heat generation zone. The homogeneous porous media, in addition to its...