scholarly journals Transient Flow of Jeffrey Fluid over a Permeable Wall

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Sana Bajwa ◽  
Saif Ullah ◽  
Ilyas Khan ◽  
Md. Fayz-Al-Asad

Transient incompressible flows of Jeffrey fluids over a permeable, flat, and infinite plate have been investigated. The plate motion is an oscillatory translation along the x-axis. Using the Laplace transform and perturbation method, the analytical solution for the velocity field in the transform domain has been obtained. The velocity field in the real domain has been determined by using the numerical Stehfest’s algorithm for the Laplace transform inversion. To have a validation of the obtained solution, we have determined the analytical solution for the flow without transpiration. It was found that when the transpiration parameter approaches zero, the solution for the flow with transpiration tends to the solution corresponding to the case without perspiration. The influence of the system parameters on fluid motion has been investigated by numerical simulations and graphical illustrations prepared with the software package Mathcad.

2020 ◽  
Vol 13 (07) ◽  
pp. 2050061
Author(s):  
Huiping Zhang ◽  
Shuyue Wang ◽  
Zhonghui Ou

The citrate secreted by the rice (Oryza sativa L.) roots will promote the absorption of phosphate, and this process is described by the Kirk model. In our work, the Kirk model is divided into citrate sub-model and phosphate sub-model. In the citrate sub-model, we obtain the analytical solution of citrate with the Laplace transform, inverse Laplace transform and convolution theorem. The citrate solution is substituted into the phosphate sub-model, and the analytical solution of phosphate is obtained by the separation variable method. The existence of the solutions can be proved by the comparison test, the Weierstrass M-test and the Abel discriminating method.


SPE Journal ◽  
2018 ◽  
Vol 23 (06) ◽  
pp. 2060-2079 ◽  
Author(s):  
Kaixuan Qiu ◽  
Heng Li

Summary Production data from hydraulically fractured horizontal wells in ultralow-permeability reservoirs have been observed to exhibit a half-slope straight line on a log-log plot of rate vs. time. Using these observations, many analytical models of linear flow have been developed to analyze the well performance in these reservoirs. However, it is relatively complicated to solve these models with the Laplace transform and numerical inversion. In this paper, a new analytical solution of a triple-porosity model is derived for unconventional oil reservoirs. The partial-differential equations (PDEs) are transformed into ordinary-differential equations (ODEs) by integration, instead of the Laplace transform. A rate-vs.-time solution in real-time space can be obtained, bypassing the numerical inversion for the Laplace transform. Our model is validated by comparison with both the numerical-model and Laplace-transform solutions. The physical meanings of the model parameters are analyzed through sensitivity analysis. The new model is then applied to field-production data for history matching and forecasting. Besides matching the production data, the pore volume (PV) of the matrix and fracture media can be estimated, which helps quantitative analysis of unconventional reservoirs.


Author(s):  
Eliete Biasotto Hauser ◽  
Ruben Panta Pazos ◽  
Marco T. M. B. Vilhena ◽  
Ricardo C. Barros

In this paper we present a proof about the convergence of the 3D Nodal-LTSN Method in order to solve the transport problem in a parallelepiped domain. For that, we define functions associated to the errors, one in the approximated flux, another in the quadrature formula and establish a relation between them. We present a Nodal-LTSN method to generate an analytical solution for discrete ordinates problems in three-dimensional cartesian geometry. We first transverse integrate the SN equations and then we apply the Laplace transform. The essence of this method is the diagonalization of the LTSN transport matrices and the spectral analysis garantees this. The transverse leakage terms that appear in the transverse integrated SN equations are represented by exponential functions with decay constants that depend on the characteristics of the material of the medium the particles leave behind. We present numerical results generated by the offered method applied to typical shielding model problems.


2015 ◽  
Vol 24 (6) ◽  
pp. 957-973 ◽  
Author(s):  
Han-Taw Chen ◽  
Jing-Hong Lin ◽  
Xiao-Jie Xu ◽  
Chein-Shan Liu ◽  
Jiang-Ren Chang

2019 ◽  
Vol 23 (Suppl. 3) ◽  
pp. 1005-1011
Author(s):  
Zhanqing Chen ◽  
Peitao Qiu ◽  
Xiao-Jun Yang ◽  
Yiying Feng ◽  
Jiangen Liu

In this paper, a new fractional derivative within the exponential decay kernel is addressed for the first time. A new anomalous diffusion model is proposed to describe the heat-conduction problem. With the use of the Laplace transform, the analytical solution is discussed in detail. The presented result is as an accurate and efficient approach proposed for the heat-conduction problem in the complex phenomena.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Zhiyi Pei ◽  
Lin Wang ◽  
Peng Wu ◽  
Jiandong Zhang ◽  
Ding Zhou

An analytical solution of stresses and deformations for two-layer Timoshenko beams glued by a viscoelastic interlayer under uniform transverse load is presented. The standard linear solid model is employed to simulate the viscoelastic characteristics of the interlayer, in which the memory effect of strains is considered. The mechanical behavior of each layer is described by the first-order shear deformation theory (FSDT). By means of the principle of minimum potential energy, a group of equations for displacements and rotation angles are derived out. The final solution is obtained by conducting the Laplace transform and the inversion of Laplace transform to the equation group. Numerical comparison shows that the present solutions and the finite element results are in good agreement. It is shown that the present results are more accurate than those obtained from the Euler-Bernoulli beam theory, especially for thick beams. And the present solutions can accurately describe the variation of stresses and deformations of the beam with the time, compared with those ignoring the memory effect of strains. Finally, the effects of the geometric parameters and material properties of the interlayer on stresses and deformations of the beam are studied in detail.


2020 ◽  
pp. 1419-1425
Author(s):  
Shaheed N. Huseen

In this paper, the time-fractional Fisher’s equation (TFFE) is considered to exam the analytical solution using the Laplace q-Homotopy analysis method (Lq-HAM)”. The Lq-HAM is a combined form of q-homotopy analysis method (q-HAM) and Laplace transform. The aim of utilizing the Laplace transform is to outdo the shortage that is mainly caused by unfulfilled conditions in the other analytical methods. The results show that the analytical solution converges very rapidly to the exact solution.


Author(s):  
Juan Sabas ◽  
Glay Cedeño ◽  
Víctor García ◽  
Luis Cobacango ◽  
Willam Moreano ◽  
...  

Debido a la complejidad del método de solución de superposición de ondas, encontrar soluciones analíticas en las ecuaciones diferenciales parciales se hace complicado. En este artículo presentamos un método teórico de solución al problema general de propagación unidimensional de ondas  que permiten dividir el problema  en otros de menor complejidad. Aplicando el método de separación de variables de Fourier y la Transformada de Laplace se obtiene detalladamente la solución analítica al problema no homogéneo del látigo. Palabras clave: Ecuación de onda, Transformada de Laplace, Solución analítica. ABSTRACT: Because of the complexity of the wave overlay solution method, finding analytical solutions in partial differential equations becomes complicated. In this article we present a theoretical method of solution to the general problem of unidimensional propagation of waves which allows the division of the problem into other smaller complexities. Applying the Fourier method of separation of variables and the Laplace transform gives the analytical solution to the non-homogeneous problem of the whip Key words: wave equation, analytical solution, Laplace Transform.


1986 ◽  
Vol 23 (04) ◽  
pp. 851-858 ◽  
Author(s):  
P. J. Brockwell

The Laplace transform of the extinction time is determined for a general birth and death process with arbitrary catastrophe rate and catastrophe size distribution. It is assumed only that the birth rates satisfyλ0= 0,λj> 0 for eachj> 0, and. Necessary and sufficient conditions for certain extinction of the population are derived. The results are applied to the linear birth and death process (λj=jλ, µj=jμ) with catastrophes of several different types.


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