The prediction of helium gas viscosity under high pressure and high temperature with the Chapman-Enskog solution and excess viscosity

The purpose of this work is to predict a helium gas viscosity under high pressure and high temperature for practical industrial uses. The suitable force constants and a collision integral for the Chapman-Enskog solution to estimate viscosity in the limit of zero density were recommended by the present author. At high density, modification of the Arp and McCarty extrapolation equation for excess viscosity was applied. A combination of the Chapman-Enskog solution and modification of the Arp and McCarty excess viscosity gives an estimation of helium gas viscosity within 2 to 5 % deviation from the existing experimental data under high-temperature and high-pressure region.