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This study aims to look into the temperature distribution on a vertical flat plate with a variable temperature boundary condition. As a novelty, the variable temperature is considered on the wall, and coupled momentum and energy equation are solved. Moreover, a novel variable change transforms the infinite boundary condition into the finite one. The partial differential governing equations were introduced and transformed into ordinary differential equations form using the similarity solution. The obtained equations were numerically solved and validated using previous research. The results showed that for a constant variable temperature index (n), increasing the Prandtl number (Pr) from 0.1 to 2 reduces the dimensionless maximum velocity by less than half and the skin friction coefficient by about 32%. In this case, the dimensionless temperature approaches zero faster; as a result, the thermal boundary layer thickness declines, and the Nusselt number (Nu) rises. Furthermore, for a constant Pr, when n increases from 0 to 1.5, the dimensionless maximum velocity and the skin friction decrease by about 38% and 23%, respectively. Since the dimensionless temperature continues to descending trend, Nu still rises in this case. [ABSTRACT FROM AUTHOR]

Although pulmonary drug delivery has been deeply investigated, the effect of the laryngeal jet on particle deposition during drug delivery with dry powder inhalers (DPI) has not been evaluated profoundly. In this study, the flow structure and particle deposition pattern of a DPI in two airway models, one with mouth-throat region including the larynx and the other one without it, are numerically investigated. The results revealed that the laryngeal jet has a considerable effect on particle deposition. The presence of laryngeal jet leads to 4-fold and 2-fold higher deposition efficiencies for inlet flow rates of 30 and 90 L/min, respectively. [ABSTRACT FROM AUTHOR]

In the present study, the heat transfer of nanofluid magnetohydrodynamic (MHD) fluid flow through a channel with radiation and viscous dissipation effect is considered. Also, the induced magnetic field is considered. The main aim of the study is to obtain the impact of the induced magnetic field, nanoparticle volume fraction, non-electrically conducting, and conducting walls on the MHD nanofluid flow and heat transfer. Hence, the governing equations include momentum, energy, and induced magnetic field equations that are transformed into non-dimensional forms. The analytical least square method (LSM) and numerical finite element method (FEM) effectively conducted for solving the problem. The results of LSM and FEM are compared, and it is observed that there is an excellent agreement. The effect of several parameters such as Hartmann number, suction/injection parameter, magnetic Prandtl number, radiation parameter, Eckert number, and nanoparticle volume fraction are demonstrated and discussed. It can be concluded that the augmentation of the Hartmann number reduces the value of velocity by up to 50%, and the magnetic Prandtl number augmentation reduces the non-dimensional velocity value of about 10% but increases the induced current density value more than twice. Moreover, the increase of radiation parameter, Eckert number, and nanoparticle volume fraction enhance the heat transfer by 20–50%. Besides, the absolute value of the induced magnetic field increases when the Hartmann number rises. Further, the injection parameter decreases the value of velocity and induced magnetic field by 40–50%; whereas, the value of temperature increases by about 40%, and the induced current density increases by 5–7 times. The suction parameter has the contrary effect. [ABSTRACT FROM AUTHOR]