Numerical modeling of heat-pipe transients

This paper describes work done to increase the understanding of numerical modeling of heat-pipe transients. The most significant contribution discussed in the paper is a method of reducing the amount of computer time required to obtain a numerical solution. It was found that time-accurate results could be obtained even if the heat-pipe's wall model and the heat-pipe's vapor model use different time steps to march through time. This leads to a reduction in computer time requirements by as much as a factor of 500. A second method of decreasing computer time requirements is also discussed. The method involves using an implicit solution algorithm instead of the explicit method used for most of this work. The implicit method was at least 10 times faster than the explicit method. Also in the paper, two different methods for modeling the heat-pipe wall transient are discussed and compared. Both methods gave comparable results; however, one method required less computer time than the other.