&DEVC ID='Back Conv Flux', QUANTITY='CONVECTIVE HEAT FLUX', XYZ=0.0,1.0,1.5, IOR=-2/ &DEVC ID='Back Adiabatic Temp', QUANTITY='ADIABATIC SURFACE TEMPERATURE', XYZ=0.0,1.0,1.5, IOR=-2/ &DEVC ID='Top Adiabatic Temp', QUANTITY='ADIABATIC SURFACE TEMPERATURE', XYZ=0.9,0.0,3.0, IOR=-3/ &DEVC ID='Right Conv Flux', QUANTITY='CONVECTIVE HEAT FLUX', XYZ=1.0,0.0,1.5, IOR=-1/ &DEVC ID='Right Adiabatic Temp', QUANTITY='ADIABATIC SURFACE TEMPERATURE', XYZ=1.0,0.0,1.5, IOR=-1/ &DEVC ID='Left Conv Flux', QUANTITY='CONVECTIVE HEAT FLUX', XYZ=-1.0,0.0,1.5, IOR=1/ &DEVC ID='Left Adiabatic Temp', QUANTITY='ADIABATIC SURFACE TEMPERATURE', XYZ=-1.0,0.0,1.5, IOR=1/ &DEVC ID='Heater Conv Flux', QUANTITY='CONVECTIVE HEAT FLUX', XYZ=0.0,0.0,0.1, IOR=3/ &DEVC ID='Heater Rad Flux', QUANTITY='RADIATIVE HEAT FLUX', XYZ=0.0,0.0,0.1, IOR=3/ &DEVC ID='Heater Wall Temp', QUANTITY='WALL TEMPERATURE', XYZ=0.0,0.0,0.1, IOR=3/ &DEVC ID='Heater Adiabatic Temp', QUANTITY='ADIABATIC SURFACE TEMPERATURE', XYZ=0.0,0.0,0.1, IOR=3/ Then, on the File menu click Import FDS/CAD file… and select the file. PyroSim users: copy the text and save as a *.fds file. Here is a listing of the FDS input file used in the example. In summary, the user needs to be aware that even if they do not explicitly define convection or radiation parameters, these fluxes will still be calculated for all surfaces using the default values.įor more detailed discussion, see the FDS User Guide and the FDS Technical Reference Guide. Exhaust Radiative FluxĪt the top OPEN surface we see that on the left side (where the flow is out of the model) the convective heat flux is zero, as shown in Figure 6, while on the right (where the flow is mostly tangent to the surface) the convective heat flux is significant, as shown in Figure 7. The calculated heat fluxes are consistent with the above discussion, with both convective and radiative components on all surfaces.įigure 4 shows the radiative flux for the heater (radiating into the enclosure) and Figure 5 shows the radiative flux for the exhaust (the radiation removes heat from the enclosure). The velocity vectors are shown in Figure 3. The top is OPEN and the front and back sides are INERT. On the left, some of the air is exhausted with the surface temperature value of 20 C. On the bottom, a heater at 500 C supplies heat by convection and radiation. There is a supply inlet on the right with a temperature of 50.0 C.
Here is an example that exercises most of the above options. How each surface handles convection and radiation heat transfer is summarized in Figure 1 below. The user will typically only specify the emissivity and is again responsible for how the wall temperature will be calculated.įDS provides some default surfaces ( INERT, ADIABATIC, and OPEN) and PyroSim tries to help the user by further categorizing surface types ( Burner, Heater/Cooler, Supply, Exhaust, and Layered). Where \(\epsilon\) is the emissivity, \(\sigma\) is the Stefan-Boltzmann constant, and the wall temperature is raised to the fourth power.
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