Ali Shaker A. A Numerical Study of Low Reynolds Number Incompressible Flow at Entrance and Disturbed Regions Of Concentric Circular Pipes. J. eng. sustain. dev. 2012;16(2):16-33. Accessed June 4, 2026. https://jeasd.uomustansiriyah.edu.iq/index.php/jeasd/article/view/1194