Theoretical Analysis of Activation Energy Effect on Prandtl–Eyring Nanoliquid Flow Subject to Melting Condition

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ikram Ullah ◽  
Rashid Ali ◽  
Hamid Nawab ◽  
Abdussatar ◽  
Iftikhar Uddin ◽  
...  

Abstract This study models the convective flow of Prandtl–Eyring nanomaterials driven by a stretched surface. The model incorporates the significant aspects of activation energy, Joule heating and chemical reaction. The thermal impulses of particles with melting condition is addressed. The system of equations is an ordinary differential equation (ODE) system and is tackled numerically by utilizing the Lobatto IIIA computational solver. The physical importance of flow controlling variables to the temperature, velocity and concentration is analyzed using graphical illustrations. The skin friction coefficient and Nusselt number are examined. The results of several scenarios, mesh-point utilization, the number of ODEs and boundary conditions evaluation are provided via tables.

2004 ◽  
Vol 82 (6) ◽  
pp. 447-458 ◽  
Author(s):  
A A Afify

The effects of radiation and chemical reactions, in the presence of a transverse magnetic field, on free convective flow and mass transfer of an optically dense viscous, incompressible, and electrically conducting fluid past a vertical isothermal cone surface are investigated. The nonlinear boundary-layer equations with the boundary conditions are transferred by a similarity transformation into a system of nonlinear ordinary differential equations with the appropriate boundary conditions. Furthermore, the similarity equations are solved numerically by using a fourth-order Runge–Kutta scheme with the shooting method. Numerical results for the skin-friction coefficient, the local Nusselt number, the local Sherwood number are given; as well, the velocity, temperature, and concentration profiles are presented for a Prandtl number of 0.7, the chemical-reaction parameter, the order of the reaction, the radiation parameter, the Schmidt number, the magnetic parameter, and the surface temperature parameter. PACS No.: 47.70.Fw


2003 ◽  
Vol 45 (1) ◽  
pp. 35-48 ◽  
Author(s):  
M. Al-Refai ◽  
K. K. Tam

AbstractA method of sequential eigenfunction expansion is developed for a semi-linear parabolic equation. It allows the time-dependent coefficients of the eigenfunctions to be determined sequentially and iterated to reach convergence. At any stage, only a single ordinary differential equation needs to be considered, in contrast to the Galerkin method which requires the consideration of a system of equations. The method is applied to a central problemin combustion theory to provide a definitive answer to the question of the influence of the initial data in determining whether the solution is sub- or super-critical, in the case of multiple steady-state solutions. It is expected this method will prove useful in dealing with similar problems.


Author(s):  
Bohua Sun

By introducing a variable transformation $\xi=\frac{1}{2}(\sin \theta+1)$, a complex-form ordinary differential equation (ODE) for the small symmetrical deformation of an elastic torus is successfully transformed into the well-known Heun's ODE, whose exact solution is obtained in terms of Heun's functions. To overcome the computational difficulties of the complex-form ODE in dealing with boundary conditions, a real-form ODE system is proposed. A general code of numerical solution of the real-form ODE is written by using Maple. Some numerical studies are carried out and verified by both finite element analysis and H. Reissner's formulation. Our investigations show that both deformation and stress response of an elastic torus are sensitive to the radius ratio, and suggest that the analysis of a torus should be done by using the bending theory of a shell.


2021 ◽  
Vol 2103 (1) ◽  
pp. 012158
Author(s):  
N V Larionov

Abstract The model of a single-emitter laser generating in the regime of small number of photons in the cavity mode is theoretically investigated. Based on a system of equations for different moments of the field operators the analytical expressions for mean photon number and photon number variance are obtained. Using the master equation approach the differential equation for the phase-averaged quasi-probability Q is derived. For some limiting cases the exact solutions of this equation are found.


2020 ◽  
Vol 24 (2 Part B) ◽  
pp. 1143-1155
Author(s):  
Salman Ahmad ◽  
Khan Ijaz ◽  
Ahmed Waleed ◽  
Tufail Khan ◽  
Tasawar Hayat ◽  
...  

The computational investigations on mixed convection stagnation point flow of Jeffrey nanofluid over a stretched surface is presented herein. The sheet is placed vertical over which nanomaterials flowing upward direction. Arrhenius activation energy and binary chemical reaction are accounted. Non-linear radiative heat flux, MHD, viscous dissipation, heat source/sink, and Joule heating are considered. Initially the non-linear flow expressions are converted to ordinary one and then tackled for series solutions by homotopy analysis method. Consider flow problem are discussed for velocity, temperature and concentration through various flow variables. Furthermore, skin friction coefficient, Sherwood number, and heat transfer rate are computed graphically.


2020 ◽  
Vol 19 (03) ◽  
pp. 2040006 ◽  
Author(s):  
M. Ijaz Khan ◽  
Faris Alzahrani

This paper deals with the entropy optimization and heat transport of magneto-nanomaterial flow of non-Newtonian (Jeffrey fluid) towards a curved stretched surface. MHD fluid is accounted. The modeling of energy expression is developed subject to Brownian diffusion, Joule (Ohmic) heating, thermophoresis and viscous dissipation. Total entropy rate is discussed with the help of fluid friction irreversibility, mass transfer irreversibility, Joule heating irreversibility and heat transfer irreversibility. Binary chemical reaction with the smallest amount of activation energy is further considered. The governing equations of Jeffrey fluid with effects of hydrodynamic, thermal radiation, heat and mass transfer were solved through built-in-shooting method. The flow variables on the entropy rate, velocity field, concentration, Bejan number, skin friction coefficient and temperature are physically discussed through various graphs. The outcomes reveal that the entropy rate increases with an enhancement in curvature parameter. Such obtained outcomes help in mechanical and industrial engineering sciences. Moreover, the velocity and temperature decays versus ratio of relaxation to retardation times are also noticed.


2018 ◽  
Vol 36 (4) ◽  
pp. 1375-1393 ◽  
Author(s):  
Thomas Berger ◽  
Timo Reis

Abstract We consider linear time-invariant differential-algebraic systems which are not necessarily regular. The following question is addressed: when does an (asymptotic) observer which is realized by an ordinary differential equation (ODE) system exist? In our main result we characterize the existence of such observers by means of a simple criterion on the system matrices. To be specific, we show that an ODE observer exists if, and only if, the completely controllable part of the system is impulse observable. Extending the observer design from earlier works we provide a procedure for the construction of (asymptotic) ODE observers.


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