マトリックス解法を用いた節点法による通気網解析

This report describes a calculation method for mine ventilation networks with a nodal head method. The generalized equations and calculation methods for solving a steady-state mine ventilation network have been written to clear the algorism of a computer program. The use of the modified Choleski's decomposition algorism has an advantage of rapid convergence to solve the linear system for the pressure corrections of nodes consisting of a symmetric matrix. The four examples of the mine ventilation networks, of which the total numbers of the nordes N are 8, 14, 51 and 141 respectively, were calculated with a personal computer (640KB, MS-DOS system). As the convergence criterion, it was employed that the maximum tolerance of the summed flow-rates in continuity at each node is less than 0.1 m³/min. Under the condition that the pressure of the main fan is kept constant and the acceleration constant for convergence is taken 1.4, the numbers of the iteration until the convergence are nearly 13 for each example. The CPU times of an iteration are roughly in proportion to N^3/2.