A PERTURBATION METHOD FOR HEAT CONDUCTION PROBLEMS WITH CYLINDRICAL AIR GAPS
处理偏心圆柱形气缝导热的一个微扰方法

The heat conduction problem is transformed into an algebraic eigenvalue problem which can be solved very simply by a perturbation method, the perturbation parameter being the small ratio between the coefficients of heat conduction in the gas and in the solid.