The effect of studying the Navier-Stokes (NS) equation of undergraduate student is examined again in this work based on the exams in the recent four years from 2019 to 2022. Proportion test method is adopted in the research. A result shows that the students can remember the equation much better via one semester study than that via semi-semester study, which seems normal but conflicts the teaching plan of the fluid mechanics course including a midterm.

This paper presents a comprehensive numerical study of the unsteady pulsatile transport of an electrically conducting fluid in an inclined porous tube. The flow is driven by pulsatile pressure gradient, periodic body acceleration and an externally applied magnetic field. The governing equations are modeled using Ohm’s law, Brinkman-extended Darcy law and Navier-Stokes equations. The pulsatile pressure gradient, periodic body acceleration, effect of gravity and horizontal inclination factors are taken into account in this study. The resulting partial differential equation is solved by weighted residual Galerkin finite element method and to deal with the transient condition Crank-Nicholson scheme is used. The computational results are presented graphically and effect of various emerging parameters on the flow characteristics is discussed.

In present work, numerical solution is performed to study the confined flow of power-law non Newtonian fluids over a rotating cylinder. The main purpose is to evaluate drag and thermal coefficients as functions of the related governing dimensionless parameters, namely, power-law index (0.5 ≤ n ≤ 1.4), d imensionless rotational velocity (0 ≤ α ≤ 6) and the Reynolds number (100 ≤ Re ≤ 500). Over the range of Reynolds number, the flo w is known to be steady. Results denoted that the increment of power law index and rotational velocity increases the drag coefficient due to momentum d iffusivity improvement which is responsible for low rate of heat transfer, because the thicker the boundary layer, the lower the heat transfer is imp lemented.

The present paper considered the thermosolutal convection in a compressible Walters B' viscoelastic fluid layer heated and soluted from below in the presence of uniform rotation. Following the linearized stability theory and normal mode analysis, the dispersion relation is obtained. For the case of stationary convection, Walters B′ viscoelastic fluid behaves like a Newtonian fluid and compressibility, rotation and stable solute gradient have stabilizing effect on the system for G >1. Graphs have been plotted by giving numerical values to the parameters to depict the stability characteristics. The stable solute gradient, rotation and viscoelasticity introduce oscillatory modes in the system which were non-existent in their absence. The sufficient conditions for the non-existence of overstability are also obtained.