Patent ID: 8774959

Claim:
A method of calculating a temperature distribution of a crucible during manufacturing, comprising a temperature calculation process for calculating a temperature distribution of a silica powder molded body using a numerical calculation method in which a calculation object is divided into meshes, and mesh-by-mesh numerical calculation is performed, and numerical calculation of the calculation object as a whole is performed based on the result of the mesh-by-mesh numerical calculation, wherein the silica powder molded body is formed, in a certain thickness, on an inner surface of a mold for manufacturing a crucible; heat plasma generated by supplying discharge current to arc electrodes is released to the silica powder molded body; the position of the arc electrodes and the discharge current are changed according to a control sequence; the temperature distribution is calculated for each of steps of the control sequence for manufacturing the crucible by melting and solidifying the silica powder molded body; the heat plasma is modeled by heat convection due to a gas flow, and radiation; an initial velocity, heat amount, and temperature of the gas flow, and a temperature and heat amount of the radiation are used as boundary conditions for the numerical calculation method; a temperature calculator calculates the temperature distribution by reading the boundary conditions corresponding to the position of the arc electrodes and the discharge current for each of the steps, from a correspondence table describing the boundary conditions of the gas flow and the radiation corresponding to the discharge current for each of the positions of the arc electrodes; the correspondence table is prepared in advance by, for each combination of the position of the arc electrodes and the discharge current, comparing an actually measured temperature distribution of the silica powder molded body irradiated with plasma and a calculated temperature distribution obtained from the numerical calculation method using the boundary conditions of the gas flow and the radiation, and adjusting the boundary conditions so that the actually measured and calculated temperature distributions coincide.