Convection Flow Of Newtonian Fluid Research Articles

Numerical investigation of mixed convection flow over a heated horizontal plate of finite length

AbstractThe present numerical study concerns the steady two‐dimensional laminar mixed convection flow of Newtonian fluid over a heated horizontal plate of finite length at a zero angle of attack for large Peclet and small Prandtl and Richardson numbers. The plate is located in a horizontal channel of finite height. Buoyancy induces a uniform hydrostatic pressure jump at the trailing edge and across the thermal wake, which is compensated by a perturbation of the outer potential flow according to the Kutta condition. Counter‐intuitively, the total lift force acting on the plate points in the opposite direction compared to the buoyancy force. The numerical solution obtained with the Finite Element solver FEniCS is compared to an analytical boundary‐layer solution from the literature. For small values of the Richardson number (Ri), an excellent agreement between the numerical and analytical solutions is observed. When Ri exceeds a certain threshold, the flow separates near the leading edge at the lower side of the plate. For some narrow intervals of Ri, three co‐existing solutions of the governing equations are found, which differ by the size of the separation bubble. The flow separation can be suppressed by bending the leading edge.

Thermal investigation for electrified convection flow of Newtonian fluid subjected to damped thermal flux on a permeable medium

The main purpose of this manuscript is to study an unsteady, MHD and free convection flow with the thermal transport for an electrical conducted, incompressible, and linearly viscous fluid flow close to a moving vertical plate in the existence of an exponential heating process. The flow area is considered permeable half-space as well as the utilization of an electromagnetic field perpendicular to fluid motion. The Caputo time-fractional derivative is utilized to present a heat flux constitutive-equation through a weak memory. The Laplace transformation technique is utilized to achieve the exact solutions of the dimensionless governing equations for the temperature field, Nusselt number, fluid velocity, and skin friction coefficient and stated in connection with Wright functions as well as a generalized G-Lorenzo-Hartley function. As a limiting case, a comparison with (Awan et al 2019 Chin. J. Phys. 60 98–106) equation (38) is done to verify the applied technique as well as for validity of our results. The influences of a variety of fractional as well as material factors are pictured with MathCad15. For low estimations of time, Fluid temperature and velocity are increased by decreasing fractional factor γ and both illustrate a contrary behavior for larger estimations of the time The fluid velocity is decreased through the large estimations of the magnetic factor

Series Solutions for Marangoni Convection on a Vertical Surface

The problem of steady, laminar, thermal Marangoni convection flow of Newtonian fluid over a flat surface is investigated. The boundary layer equations for the momentum and energy equations are transformed with the similarity solutions to ODEs to obtain the analytical approximate solutions. The analysis assumes that the temperature variation is a power law function of the location. The approximate solutions to the similarity equations are obtained by exponential series. The effects of the power law exponent and Prandtl number on the velocity and temperature profiles are presented.

Natural convection flow in an open rectangular cavity with cold sidewalls and constant volumetric heat source

The transient two-dimensional natural convection flow of Newtonian fluid in an open rectangular cavity has been studied numerically. The flow is induced due to constant internal heat generation. The alternate direct implicit (ADI) finite difference, together with upwind finite-difference scheme and successive over relaxation method, are used to solve the non-dimensional equations numerically. Effects of Rayleigh number, Ra, Prandtl number, Pr, and cavity aspect ratio, A, on the flow patterns and isotherms as well as on the heat transfer rate are studied graphically. The maximum temperature induced due to the constant volumetric heat source is found with the increase in cavity width, and to decrease with the increase in Prandtl number and Rayleigh number. The numerical model employed here is found to be in good agreement with the previous work.

Free Convection Flow of Newtonian Fluid along a Vertical Plate Embedded in a Double Layer Porous Medium.

Porous medium has got a great interest especially in the recent years, for its wide application in geophysics, petroleum, and air conditioning. Many studies related to porous medium were performed, and most of them are dealing with constant porosity. For the fact that porosity is non-uniform, a great concern has been directed toward the variable porosity studies. In this study, the effects of a double layer porous medium on the free convection along vertical plate embedded in this porous medium were investigated. The governing partial nonlinear differential equations were transformed into a set of ordinary differential equations, which have been solved by the fourth-order Runge-Kutta method. The results are obtained for different layer permeability K, and layer length, L. One case is compared with the previous study, and the result is found to be in good agreement with the result of previous study

Flow reversal in a combined convection flow of Newtonian fluid in a vertical duct

Numerical solutions are presented for the problem of steady laminar combined convection flows in vertical parallel-plate ducts, with linearly varying wall temperatures. Neglecting streamwise diffusion in the analysis leads to a parabolic set of governing equations. These are solved using a marching technique for an implicit finite-difference scheme with vorticity, streamfunction and temperature as variables. A constant wall temperature is applied after a certain height to mimic downhole conditions in an oil well. Various values of the governing parameter,Gr, are considered, including the forced convection solution,Gr=0, whilstPr is set at a value of unity in order to present the numerical method. As |Gr| increases reverse flow regions appear and these are dealt with using a modification of the standard marching technique. Results are obtained in terms of velocity profiles, local Nusselt numbers, flow average temperatures and friction factors, with particular attention applied to the case where the wall temperature decreases with height.