Monte Carlo Calculation Method For Complex Surface Heat Radiation

As the main way of heat transfer in fire,heat radiation often plays a decisive role in the development and spread of fire.The study of heat radiation is mainly to calculate radiant heat energy,but its calculation method is usually very complicated,mainly two aspects Causes:1.The shape of the flame in the fire is not fixed,resulting in the radiation surface is complex,The radiation surface is assumed to be a particular geometry during the calculation,in order to simplify the calculation of heat radiation.Conventional calculations often use conventional geometries to replace the flame.Mainly there: point source,long board shape,cone,cylinder and cubic cylinder and so on.2.The surface of the object to receive radiation is often more complex,must consider:surface shape,scattering distribution characteristics,surface spectral properties,surface directivity,temperature and position changes.The traditional heat transfer theory only has a theoretical solution to the radiation calculation of some regular emission surfaces and the radiation model of the receiving surface.The real fire scene is complicated even if it is flame or the surface of the object that receives the radiation.Therefore,these theoretical models Often can not be applied to the real fire heat radiation calculation.it means that the real fire scene of the heat radiation is often unable to find a simple and effective way to calculate.However,this paper uses the Monte Carlo method to calculate the thermal radiation between complex surface objects.The purpose of this paper is to find a general algorithm for the calculation of the heat radiation of any shape of the emission surface and the arbitrary shape of the receiving surface.The method used in this paper is to use a small triangular surface to fit the complex combustion flame surface and the complex surface of the receiving radiation object,the use of a large number of small triangles,approximate simulation of the real radiation surface and the surface of the receiving radiation objects.Therefore,the complex radiation calculation model is transformed into a number of small triangular surface between the radiation calculation model,so as to realize the calculation of complex surface heat radiation.