Numerical simulation on coupling heat-transfer of low oxygen gas flowing through PMMA tube

In order to know cooling situation of gas flowing through PMMA and design the cooling device which meets required gas outlet temperature, the change of thermal degradation process along radial direction of tube inwall was numerically simulated when gas flowing through PMMA. Combining moving mesh and mass mix technique, the deduced relation expression between average warming-up rate and characteristic degradation temperature of PMMA tube inwall was used for solving the above problem. The curves of tube inwall contour vs time and flow field parameters vs time under fixed and unfixed gas inlet area conditions were obtained. The calculation results show that temperature drop under fixed gas inlet area is more than that under unfixed gas inlet area. For fixed gas inlet area, radial degradation degree is the lowest in the inlet of tube inwall, and biggest at a distance from inlet of tube inwall. For unfixed gas inlet area, radial degradation degree is the biggest in the inlet of tube inwall, but lowest in the outlet of tube inwall.