One-dimensional P1 method for gas radiation heat transfer in spherical geometry

•A P1 model for gas radiation in 1D spherical geometry is developed.•P1 is better than DOM for pure gas cases.•The error induced by gas radiation model is larger than RTE. Radiation heat transfer is important in spherical flame modeling, such as to determine the flame speed. It is beneficial to use one-dimensional (1D) model to solve the three-dimensional problems with spherical symmetry, while little work reports the 1D non-gray radiation heat transfer in spherical coordinates. This paper developed a 1D first order spherical harmonics (P1) model for the non-gray gas radiation in a sphere. The statistical narrow-band k-distribution (SNBCK), the weighted-sum-of-gray-gases (WSGG) and the spectral line based WSGG (SLW) are used for the non-gray radiation properties. The accuracy of the non-gray P1 method is analyzed and compared with discrete ordinates method (DOM). Results show that accuracy of the P1 method is close to DOM, except for gas mixture conditions.