Belhocine, AliAliBelhocineAbdullah, Oday IbraheemOday IbraheemAbdullah2020-05-262020-05-262020-04-01International Journal of Modeling, Simulation, and Scientific Computing 2 (11): 2050013 (2020-04-01)http://hdl.handle.net/11420/6177In this paper, the assumptions implicited in Leveque's approximation are re-examined, and the variation of the temperature and the thickness of the boundary layer were illustrated using the developed solution. By defining a similarity variable, the governing equations are reduced to a dimensionless equation with an analytic solution in the entrance region. This report gives justification for the similarity variable via scaling analysis, details the process of converting to a similarity form, and presents a similarity solution. The analytical solutions are then checked against numerical solution programming by FORTRAN code obtained via using Runge-Kutta fourth order (RK4) method. Finally, other important thermal results obtained from this analysis, such as; approximate Nusselt number in the thermal entrance region was discussed in detail. A comparison with the previous study available in literature has been done and found an excellent agreement with the published data.en1793-961520202dimensionless variablesNusselt numberRunge-Kutta methodtemperaturethermal boundary layerThermal entrance regionJournal Article10.1142/S1793962320500130Other