Multiplicity and stability of boiling on a thin cylinder with heat generation

摘要

A theoretical investigation was conducted to explore multiplicity and stability of boiling on a thin cylinder with different heat generations. The steady temperature distributions of the boiling on the cylinder were calculated under different boundary conditions and heat generations, and multiplicity phenomena were found in the boiling distribution diagram. In the multiplicity regions with proper cylinder length, there can be two or three steady temperature distributions with different boiling modes. In addition, the linear stability analyses were employed to investigate boiling system, and the maximum eigenvalue was derived to determine the stability of steady distribution. The obtained maximum eigenvalue distribution was shown to correlate well with the steady temperature and heat flux distributions, and the multiplicity phenomena also existed in the boiling stability diagram. In the multiplicity region, only one steady temperature distribution of the boiling was unstable with positive eigenvalue, while the others were stable with negative eigenvalue. Compared with available experimental results, the present model can very well explain the multiplicity and stability of boiling on the wires or fins.