ريسان فارس حمد المالكي

Axially-functionally graded materials are/ types of traditional composite materials in which the mechanical and physical properties are gradually varied from one end to the other. They were used extensively in industries such as defense, automotive and aerospace because of the ability to design its mechanical and physical properties. Two numerical models are built in this work in order to investigate the deflection of a simply supported beam made by axial-functionally graded material. The first model is the new model and it is built by adopting the Rayleigh Method, while the second model used the Finite-Element technique to build an 1D model utilizing the ANSYS APDL. The mechanical and physical of the axial-functionally graded beam were changed in axial direction according to Power-Law Equation. The new model, based on Rayleigh Method ANSYS- 1D model, shows an excellent agreement with the results and available literature. In addition to the validation of the two models, the influences of elastic moduli ratio and material distribution on the maximum static deflection and its position were studied. In ANSYS- 1D model, the position of the maximum deflection was deviated from the middle span of A-FG beam and this deviation in position of maximum deflection reduces, as well as increases the index of power-law equation and the elastic moduli ratio (ME-Ratio) when it diverges from 1.

Solar energy is one of the most efficient forms of renewable energy. Solar air collectors are promising utilization of solar energy. The present study used unsteady three-dimensional Computational Fluid Dynamic (CFD) analysis to investigate the heat transfer and fluid friction in solar air collectors with smooth and v-corrugation absorber plates. The studied parameters are Reynolds number, v-corrugation height, and pitch. Three Reynolds number (500, 1000, 1500) values were used with three arrangements configuration of the v-corrugation of relative heights of 0.10, 0.16, and 0.23. Roughness pitches varied between 1.33, 1.66, and 2. By comparing the simulated thermal efficiency with the currently known experimental values, great agreement can be approved. Results show the superiority of the performance of v-corrugated collector against the traditional or smooth type. The outlet temperature obtained in case of relative roughness height = 0.23 and relative roughness pitch = 2 is 61 °C, while it is 53 °C for a smooth type. Also, a higher thermal efficiency of 46.7 % can be obtained compared to 33.01% for smooth type.

Conjugate heat transfer is a complex problem because heat is transferred from a solid medium to a liquid medium through their interfaces. The steady-state laminar flow formed inside the microtubules is subjected to a constant temperature at the outer sidewall surface. These images cover a wide range of wall-to-fluid thermal conductivity ratios (ksf = 1, 2, 3, 4, and 5) and wall thickness-to-inner diameter ratios (δ/Ri = 0.25, 0.5, 0.75, 1, 1.25, and 1.5) and Reynolds numbers (Re = 200, 400, 600, 800, and 1,000). The results are processed by a Fluent program based on the finite volume method to numerically integrate the driver’s differential equations. The results show that increasing the wall-to-fluid thermal conductivity ratio ksf increases the inner wall dimensionless temperature and decreases the average Nusselt number. Conversely, an increase in the ratio of wall thickness to inner diameter results in a decrease in the dimensionless temperature of the inner wall and an increase in the average Nusselt number.

Steady, laminar, incompressible, working fluid behaves as non-Newtonian power law, which develop, two dimensional flows through sudden expansion channel. This type has been investigated numerically and was performed by using ANSYS Fluent software in this work based on Finite Volume Approach. It is assumed Expansion Ratio ER and Expansion Length Ratio LR are (3:1) and (25:2) respectively. The low Reynolds number range vary with values of 20, 40, and 60 based on power law index values (0.5, 1, 1.5, and 1.8). Predicted results of the symmetrical flow represents velocity profile, static pressure coefficient, stream lines, and reattachment length. The calculations show that static pressure coefficient decreases, when modified Reynolds number increases. Also increment in modified Reynolds number and power law index, leads to increment in strength and diameter of recirculation and reattachment length.

Abstract-- This is the work deals with a numerical study of laminar flow of two - dimensional, incompressible, and steady state over rotating circular cylinder. The solution of the flow is presented for dimensionless rotation rate varying from (1 – 6) (in the steps of 1) at each value of Reynolds number based on diameter of cylinder is (200, 400, 800, and 1000). Navier – Stokes and continuity equations were solved numerically by using finite volume technique is conducted with FLUENT version (6.2) package program was used in present work. Stream lines or function and vorticity contours and pressure, lift, and skin friction coefficients results are presented along curve length of cylinder at each value of rotation rate and Reynolds number. The results of lift coefficient and stream lines and vorticity contours were compared with other previously published research that presented support the validity of results. Results have shown approximately increase values of pressure, and skin friction coefficients with increasing of rotation rate at known Reynolds number.

Abstract-- This is study investigated the effect increasing the angular velocity on the axial velocity profile and pressure gradient for steady state, three dimensional, incompressible, isothermal, and laminar flow of a Newtonian fluid through eccentric annular duct. The results are presented for angular velocity range (0, 50, 100, 150, 200, and 250) rpm at axial Reynolds number 200 based on bulk axial velocity with radius ratio 0.5 where FLUENT software version (6.2) is used to solve continuity and momentum equations. The results of axial and tangential velocity for four sectors were found to be in good agreement with other previously published research at eccentricity are 0.2 and 0.5. The results show that the axial velocity varies with varying in rotational speed of inner cylinder and the axial pressure gradient increases with increasing in rotational speed. Also when inner cylinder is rotated, the axial velocity profile become nonaxisymmetry around center of radial gap of annular pipe at eccentricity of 0.2 and 0.4.