A numerical investigation has been performed to study the effect of eccentricity on unsteady state, laminar aiding mixed convection in a horizontal concentric and eccentric cylindrical annulus. The outer cylinder was kept at a constant temperature
while the inner cylinder was heated with constant heat flux. The study involved numerical solution of transient momentum (Navier-Stokes) and energy equation using finite difference method (FDM), where the body fitted coordinate system (BFC) was
used to generate the grid mesh for computational plane. The governing equations were transformed to the vorticity-stream function formula as for momentum equations and to the temperature and stream function for energy equation.
A computer program (Fortran 90) was built to calculate the bulk Nusselt number (Nub) after reaching steady state condition for fluid Prandtl number fixed at 0.7 (air) with radius ratio ( =2.6), Rayleigh number (Ra=200), Reynolds number (Re=50) for both concentric and eccentric cylindrical annulus with different eccentricity ratios (ε=0, 0.25, 0.50, 0.75) and angular positions (φo=0o
, 45o , 90o , 135o , 180o ).
The results show a reasonable representation to the relation between Nusselt number and (ε, φo). Generally, Nub decreased with the increase in (ε and φo). Also, results show that the best thermal performance for the inner cylinder was at the angular
position (φo=0o ) for eccentricity ratio (ε=0.25), while the maximum reduction in the rate of heat transfer for the inner cylinder was at the angular position (φo=180o) for eccentricity ratio (ε=0.75).
Comparison of the result with the previous work shows a good agreement.
This paper analyzes a piled-raft foundation on non-homogeneous soils with variable layer depth percentages. The present work aims to perform a three-dimensional finite element analysis of a piled-raft foundation subjected to vertical load using the PLAXIS 3D software. Parametric analysis was carried out to determine the effect of soil type and initial layer thickness. The parametric study showed that increasing the relative density from 30 % to 80 % of the upper sand layer and the thickness of the first layer has led to an increase in the ultimate load and a decrease in the settlement of piled raft foundations for the cases of sand over weak soil. In clay over weak soil, the ultimate load of the piled raft foundation w
... Show MoreThe accurate identification of internal and external pressures in thick-walled hyperelastic vessels is a challenging inverse problem with significant implications for structural health monitoring, biomedical devices, and soft robotics. Conventional analytical and numerical approaches address the forward problem effectively but offer limited means for recovering unknown load conditions from observable deformations. In this study, we introduce a Graph-FEM/ML framework that couples high-fidelity finite element simulations with machine learning models to infer normalized internal and external pressures from measurable boundary deformations. A dataset of 1386 valid samples was generated through Latin Hypercube Sampling of geometric and l
... Show MorePurpose: This study's objective is to assess this relationship in the context of the banking industry in Iraq. The human resources management practices (HRMPs) Theoretical framework: in this study included recruiting and selection, training and development, performance appraisal, compensation and reward to testing relationship HRMPs. Design/methodology/approach: in this study; We analysed by used a quantitative approach, and 246 employees were selected as a sample and given a questionnaire. The SPSS software was used to examine the data that were obtained from the questionnaire. Findings: The study's findings revealed a variety of hypotheses and conclusions, including the following: comp
... Show MoreWe conducted an experiment in a greenhouse at the research station belonging to the Department of Plant Protection / Ministry of Agriculture, in Abu Ghraib area during the spring and autumn season 2022-2023, to study the population density of the whitefly on two varieties of sweet pepper plant (Charisma and Sierra Nevada). The experiment was laid out in a randomized complete block design “RCBD” with three replicates for each variety. The results showed that in spring season the population density of
This article reveals the first record of the parasitoid wasp, Monodontomerus obscurus Westwood (Hymenoptera, Torymidae) from Iraq. A total of 27 specimens were emerged from mud nests of sphecoid wasp of Sceliphron sp. (Hymenoptera, Sphecidae), that collected from a wall at a residential garden in Dohuk province. A short morphological description is presented.
The European continent suffers from the presence of some separatist tendencies, as it becomes clear the impact of racial and ethnic variables driving towards the crystallization of separatist conflicts that led to the success of some of them in the establishment of sovereign states, while the other failed to achieve this, the research focused on the importance of matching geographical, cultural and political criteria In the success of separatist trends, he also focused on the role of the policies imposed by the mother state in curbing or exacerbating the separatist trend through the level of justice in the distribution of wealth between the regions, and what are the rights and duties of those oppressed and abused minorities, so the r
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