Calculate the viscosity of hydrogen across a range of temperatures and pressures.
The viscosity of a gas is based on the molecular diffusion that transports momentum between layers of flow. The kinetic theory of gases is able to accurately predict the viscosity of a gas, but only where the viscosity is independent of any change in pressure, and viscosity always increases as temperature increases. In cases where these two assumptions do not hold true, the kinetic theory of gases will not be able predict the viscosity of a gas.
This paper uses a symbolic regression approach to obtain both the functional form and the coefficients for a wide-ranging correlation for the viscosity of normal hydrogen. The authors cover a wide range of temperatures and pressures, going from triple-point temperature to 1000 K and pressures up to 200 MPa. For saturated liquids, the estimated uncertainty is 4% from the triple point to 31 K; for the supercritical fluid phase, the estimated uncertainty is 4% at pressures to 200 MPa; and for the range of 200 K to 400 K at pressures up to 0.1 MPa, the estimated uncertainty is 0.1%.Read the research paper »