Application of the mean radiant temperature method in the evaluation of radiative heat exchanges between a fire front and a group of firemen

2014 ◽  
pp. 95-101 ◽  
Author(s):  
Eusébio Z. E. Conceição ◽  
Domingos X. Viegas
Keyword(s):  
Radiative Heat ◽  
Mean Radiant Temperature ◽  
Temperature Method ◽  
Fire Front ◽  
The Mean ◽  
Radiant Temperature ◽  
Heat Exchanges

Comparatives study of radiative heat exchanges between fire front from fireman and pine tree in warm thermal conditions

2020 ◽  
pp. 39-49
Author(s):  
Eusébio Conceição ◽  
João Gomes ◽  
Maria Manuela Lúcio ◽  
Jorge Raposo ◽  
Domingos Viegas ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Human Body ◽  
Thermal Conditions ◽  
Mean Radiant Temperature ◽  
Human Body Model ◽  
Tree Model ◽  
Pine Tree ◽  
Fire Front ◽  
Radiant Temperature ◽  
Heat Exchanges

This work presents the development of a numerical design in forest fire environments. A comparison between a tree body and a human body (fireman) thermal response systems is made. The three-dimensional pine tree model is constituted by trunk, branches and leaves represented by cylindrical elements. The human body model is divided into 35 elements and considers its thermoregulation. In both systems, special attention is required with conduction, convection, evaporation and radiation. There are also considered the heat exchanges by radiation between the fire front and both bodies. A vertical fire front, with 2 m of height and 20 m of length, was considered. The air temperature, air velocity, air relative humidity and mean radiant temperature are used. Two cases were studied: a pine tree and a fireman placed nearby the fire front. The results of the flame mean radiant temperature, temperature of the bodies surfaces and view factors are obtained. The results show that the fireman is most exposed than the pine tree to the fire front. Due to the human thermoregulatory and clothing systems, the fireman has a skin surface temperature much lower than the surface temperature in the trunks, branches and leaves of the tree. The evaporation in the tree is not sufficient to control the temperature.

scholarly journals The most problematic variable in the course of human-biometeorological comfort assessment — the mean radiant temperature

2011 ◽  
Vol 3 (1) ◽  
Author(s):  
Noémi Kántor ◽  
János Unger
Keyword(s):  
Thermal Comfort ◽  
Short Wave ◽  
Urban Environments ◽  
Outdoor Thermal Comfort ◽  
Radiation Environment ◽  
Wave Radiation ◽  
Mean Radiant Temperature ◽  
Radiation Fluxes ◽  
The Mean ◽  
Radiant Temperature

AbstractThis paper gives a review on the topic of the mean radiant temperature Tmrt, the most important parameter influencing outdoor thermal comfort during sunny conditions. Tmrt summarizes all short wave and long wave radiation fluxes reaching the human body, which can be very complex (variable in spatial and also in temporal manner) in urban settings. Thermal comfort researchers and urban planners need easy and sound methodological approaches to assess Tmrt. After the basics of the Tmrt calculation some of the methods suitable for obtaining Tmrt also in urban environments will be presented.. Two of the discussed methods are based on instruments which measure the radiation fluxes integral (globe thermometer, pyranometer-pyrgeometer combination), and three of the methods are based on modelling the radiation environment with PC software (RayMan, ENVI-met and SOLWEIG).

scholarly journals SPUCAL_mrt as a New Model for Estimating the Mean Radiant Temperature in Arid Lands

2015 ◽  
Vol 74 ◽  
pp. 273-280 ◽  
Author(s):  
Ahriz Atef ◽  
Zemmouri Noureddine ◽  
Fezzai Soufiane
Keyword(s):  
Arid Lands ◽  
Mean Radiant Temperature ◽  
New Model ◽  
The Mean ◽  
Radiant Temperature

scholarly journals Thermal comfort of patients in hospital ward areas

1977 ◽  
Vol 78 (1) ◽  
pp. 17-26 ◽  
Author(s):  
R. M. Smith ◽  
A. Rae
Keyword(s):  
Steady State ◽  
Thermal Comfort ◽  
Air Temperature ◽  
Hospital Ward ◽  
Patient Comfort ◽  
Mean Radiant Temperature ◽  
Air Velocity ◽  
Assessment Techniques ◽  
The Mean ◽  
Radiant Temperature

SUMMARYThe patient is identified as being of prime importance for comfort standards in hospital ward areas, other ward users being expected to adjust their dress to suit the conditions necessary for patient comfort. A study to identify the optimum steady state conditions for patient comfort is then described.Although this study raises some doubts as to the applicability of the standard thermal comfort assessment techniques to ward areas, it is felt that its results give a good indication of the steady-state conditions preferred by the patients. These were an air temperature of between 21.5° and 22° C and a relative humidity of between 30% and 70%, where the air velocity was less than 0.1 m/s and the mean radiant temperature was close to air temperature.

The calculation of the mean radiant temperature of a subject exposed to the solar radiation—a generalised algorithm

2005 ◽  
Vol 40 (3) ◽  
pp. 367-375 ◽  
Author(s):  
Maria La Gennusa ◽  
Antonino Nucara ◽  
Gianfranco Rizzo ◽  
Gianluca Scaccianoce
Keyword(s):  
Solar Radiation ◽  
Mean Radiant Temperature ◽  
The Mean ◽  
Radiant Temperature

scholarly journals Analysis and Modeling of Physiologic Equivalent Temperature of an Outdoor Environment

2020 ◽  
pp. 77-91
Author(s):  
Adinife P. Azodo ◽  
Salami O. Ismaila ◽  
Femi T. Owoeye ◽  
Titus Y. Jibatswen
Keyword(s):  
Land Cover ◽  
Ambient Temperature ◽  
Land Surface ◽  
Physiological Stress ◽  
Outdoor Environment ◽  
Mean Radiant Temperature ◽  
Equivalent Temperature ◽  
Physical Measurements ◽  
The Mean ◽  
Radiant Temperature

This study developed a model that depicts the relationship, strength, and direction of the causality between the predictor variables (microclimatic variables) and a response variable (ambient temperature) interpreted for the physiologic equivalent temperature of an environment. Data collected were microclimatic variables which include air circulation, relative humidity, mean radiant and ambient temperatures over land cover materials namely tarmac, grass, soil and concrete at the premises of Federal University Wukari, Taraba state of Nigeria at a guided height of 1.1 m. The data was collected using physical measurements with respect to time of the day; morning (8:00 – 9:00 am), afternoon (1:00 – 2:00 pm) and evening (6:00 – 7:00 pm) and season of the year; dry (November – March) and wet (April – October) from April 2016 to March 2017. Comparative analysis of the data obtained from the survey and that of the developed model gave percentage variation range of 0.5 – 6.8%. However, in both cases there is an association between the microclimatic variables and the ambient temperature on each of the considered materials, season and measurement intervals. The ranges of the physiological equivalent temperature for different grades of thermal sensation and physiological stress on the land cover materials in this study was 30.2 – 43.3 °C which of intense thermal range. The physiologic equivalent temperature analysis for the land cover materials showed that there was variation in the mean radiant temperature with intense thermal effect in season and measurement intervals. This study depicted that combined use of several land cover materials in a particular area has impact on the mean radiant temperature. This necessitate that the design of the land surface environment should be with due consideration to the convective heat exchange between the outdoor workers and the ambient environment for their thermal comfort and occupational heat stress.

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