MATHEMATICAL MODELLING OF NEWTONIAN FLUIDS FLOW PHENOMENA THROUGH DIFFERENT RATIOS OF BACKWARD STEP DUCT. Kashf J. Multidiscip. Res. [Internet]. 2025 Jan. 31 [cited 2026 May 14];3(01):65-104. Available from: https://www.kjmr.com.pk/kjmr/article/view/818