TY - JOUR TI - An improved algebraic model for by-pass transition for calculation of transitional flow in pipe and parallel-plate channels AU - Nering Konrad AU - Rup Kazimierz JN - Thermal Science PY - 2019 VL - 23 IS - 14 SP - 1123 EP - 1131 PT - Article AB - Modified algebraic intermittency model developed by E. Dick and S. Kubacki was used to describe laminar-turbulent transition. In this work a modification of this model was made for simulating internal flows in pipes and parallel-plate channel. In particular, constants present in this model were modified. These modified constants are the same for different flows in pipes and parallel-plate channels. In this work, a dependence of friction factor on Reynolds number and turbulence intensity were determined as well as the localization of laminar breakdown and fully developed flow. Obtained results were compared with theoretical and experimental data presented in the literature.