Numerical simulation of gas through PMMA tube

To design the controlling temperature equipment with desired outlet gas temperature by learning the gas temperature decrease through PMMA tube, transient heat transfer mathematical model of PMMA thermal degradation was established, and the velocity of degradation rate of moving boundary grid between solid and fluid was obtained. STAR-CD software was used to simulate the difference between average volume temperature and interior wall temperature vs. time in axis direction aided by user subroutine programs. The third thermal boundary condition equation joined with the degradation rate of interior wall was used to get the contour of interior wall vs. time under the condition of identical heat flux between fluid and solid in axis direction. The numerical simulation results agrees well with that of measurements.