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An analysis is carried out to study the effects that blowing/injection and suction on the steady mixed convection or combined forced and free convection boundary layer flows over a vertical slender cylinder with a mainstream velocity and a wall surface temperature proportional to the axial distance along the surface of the cylinder. Both cases of buoyancy forces aid and oppose the development of the boundary layer are considered. For the investigated problem, the governing non-linear partial differential equations and their associated boundary conditions are transformed into coupled non-linear ordinary differential equations by using similarity transformations. This equation is solved both by a newly developed analytic technique, namely homotopy analysis method (HAM) and by a numerical method employing the shooting method. The convergence of the obtained series solutions is carefully checked. The physical significance of interesting parameters on the velocity profile and the temperature profile are shown through graphs and discussed in detail. The values of the skin friction coefficient, the local Nusselt number, curvature parameter, buoyancy or mixed convection parameter and Prandtl number are tabulated. Comparison is also made with the corresponding results of viscous fluid with no mixed convection and an excellent agreement is noted. [ABSTRACT FROM AUTHOR]

Abstract: This paper deals with a theoretical (numerical) analysis of the effects that blowing/injection and suction have on the steady mixed convection or combined forced and free convection boundary layer flows over a vertical slender cylinder with a mainstream velocity and a wall surface temperature proportional to the axial distance along the surface of the cylinder. Both cases of buoyancy forces aid and oppose the development of the boundary layer are considered. Similarity equations are derived and their solutions are dependent upon the mixed convection parameter, the non-dimensional transpiration parameter and the curvature parameter, as well as of the Prandtl number. Dual solutions for the previously studied mixed convection boundary layer flows over an impermeable surface of the cylinder are shown to exist also in the present problem for aiding and opposing flow situations. [Copyright &y& Elsevier]

Solitary waves can evolve into breakers in the nearshore area, generating strong destructive forces, especially for plunging breakers. In the present study, experiments are conducted to investigate plunging solitary waves propagating over a trapezoidal bar and to quantify their subsequent hydrodynamic forces on a cylinder. To do so, solitary waves are designed to break at varying phases and to strike the cylinder differently in space to examine their hydrodynamic forces. Furthermore, consideration of structural responses influencing measured forces for non-rigid structures provides the basis of an equation of motion that facilitates the extraction of hydrodynamic forces from measured forces. Additionally, the relation of cylinder's properties to surface elevations are evaluated and subsequently used to extract the hydrodynamic forces. The results show that the measured forces, extracted hydrodynamic forces, and dynamic amplification factors (DAF: ratio between the measured force and hydrodynamic force) achieve their highest values approximately at the same breaking phase, that is when the plunging jet has curled down, but prior to its impingement on the water surface, and this remains valid for different incident wave heights. Lastly, with an assumed asymmetrical triangular-pulse force, theoretical DAF is calculated and presents less than a 20% difference to the experimental DAF. • Experiments on plunging solitary waves impacting on a cylinder were conducted. • A method is proposed to extract hydrodynamic forces under different water levels. • Highest hydrodynamic forces occur at the breaking phase with a curling down jet. [ABSTRACT FROM AUTHOR]

This work is focused on the study of heat and mass transfer by mixed convection over a vertical slender cylinder in the presence of chemical reaction and thermal-diffusion and diffusion-thermo effects. The resulting equations have the property whereby they reduce to various special cases previously considered in the literature. An adequate implicit, tri-diagonal finite-difference scheme is employed for the numerical solution of the obtained equations. Various comparisons with previously published work are performed and the results are found to be in excellent agreement. Representative results for the local skin-friction coefficient, local Nusselt number, and the local Sherwood number illustrating the influence of the surface transverse curvature parameter, Richardson number, concentration to thermal buoyancy ratio, Schmidt number, chemical reaction, and the Dufour and Soret numbers are presented and discussed. © 2013 Wiley Periodicals, Inc. Heat Trans Asian Res, 42(7): 618-629, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.21045 [ABSTRACT FROM AUTHOR]