抄録
Non-linear k-ε model is applied to viscoelastic turbulent flow. In formulation of a RANS for viscoelastic fluid flow, two main improvements are needed: a modified eddy viscosity closure, and a new closure for a cross-correlation term between the fluctuating components of the viscoelastic conformation and rate of strain tensors (Λ_<ij>) appearing when constitutive equation is averaged. Λ_<ij> was often modeled by the Reynolds stress in the literature. Since many previous studies have constructed a set of RANS equations based on the linear k-ε model, Λ_<ij> was modeled assuming the isotropic Reynolds stress. In this study, anisotropy of Reynolds normal stress was expressed by employing non-linear k-ε model. Thus, from the standpoint that it may be possible to obtain more exactly the normal components of the Reynolds stress, we proposed a new model of Λ_<ij>. Moreover, we found that C_μ, of non-linear k-ε model predicted well the eddy viscosity without modification.
