摘要

Taking the limit of small Reynolds number for a vessel being filled with compressed gas, the energy equation was found to asymptote to the unsteady heat conduction equation with heat generation and variable density. This equation was solved analytically for cylindrical and spherical geometry. Assuming the density changes linearly with time, a solution is obtained which is identical in form to the constant density solution if the Fourier number is defined using the log-mean density rather than the instantaneous density. At steady state conditions, the Nusselt number based on the diameter for cylinders with aspect ratios larger than 1 rapidly approaches an integer solution of Nu(D) = 8. For cylinders with aspect ratios less than 1, the Nusselt number based on the cylinder length (height) characteristic dimension rapidly approaches Nu(L) = 6. It is shown experimentally and numerically that during compression filling, the heat transfer asymptotically approaches this analytical solution at low Reynolds numbers.

  • 出版日期2017-6

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