Numverical Analysis of Entrance Length in Steady and Incompressible Pipe Flow

In circular pipe flows, due to viscous effects the flow develops first from pipe inlet then becomes a fully developed flow. Flow characteristics such as shear stress, velocity profile and turbulence flow statistics while change in the developing flow, they do not change in the fully developed flow. Therefore, while the fully developed pipe flows find solutions with various empirical relations, the developing pipe flows is still not fully solved. The distance measured from the pipe inlet until the fully developed flow exists is called the entrance length. Especially in shortpipe heat transfer processes such as heating and cooling, to know the entrance length is very important to determine the pressure losses. Therefore, in this study, the entrance length were investigated with numerical solution across different pipe diameters, roughnesses and Reynolds numbers ranging from 2000 to 25000 in the steady and tubular water flows. As a result of the analysis, a numerical correlation was proposed for the dimensionless entry length which was well agree with the numerical dat