A numerical study of the two-dimensional steady free convection flow in an inclined annulus between two concentric square cavities filled with a porous medium is presented in this paper for the case when the side outer walls are kept with differentially heated temperature while the horizontal outer walls and the inner walls are insulated. The heated wall is assumed to have spatial sinusoidal temperature variation about a constant mean value. The Darcy model is used and the fluid is assumed to be a standard Boussinesq fluid. For the Cartesian coordinate system, the governing equations which were used in stream function form are discretized by using the finite difference method with successive under – relaxation method (SUR) and are solved by Gauss-Siedel iterative method. The upwind scheme was used for the transport terms in the energy conservation equation. The results are presented to demonstrate the streamlines, the isotherms, and the Nusselt number depending on the Rayleigh number ranging from (Ra =10 to 1000), dimension ratio from (Dr = 0.15 to 0.45), and the inclination angle from (= 0o to 45o). Also the effects of the amplitude (=0 to 1) and the wave number (f =0 to 5) of the heated side wall temperature variation on the free convection are investigated. The results show the effect of previous parameters (Ra, Dr,, , and f) on the flow fields and temperature profiles. It also show that the average Nusselt number is a strong function of the Rayleigh number, inclination angle, dimension ratio, and temperature variation. The peak value of the average Nusselt number based on the hot wall temperature is observed to occur at dimension ratio of (0.15), inclination angle of (40.1°), amplitude and wave number (1 & 0.75) for Rayleigh number of (1000).
Abstract
The scope of the humanitarian tragedies in the Arab region has widened after the conflicts that erupted over the past years, exacerbation to include educational, cultural, and social dimensions, economic and moral aspects of the displaced families, especially after the emergence of terrorist organizations and sectarian conflicts which overthrew human and led to various political and demographic changes, forcing citizens to leave their homes, fleeing with their families from the danger of murder, terrorism, and violation to other safer areas inside or outside their countries. Women and children were the vast majority of the displaced who were subjected to great pressures, The host communities bore the pro
... Show MoreThe current research aims to find out (the effectiveness of teaching TRIZ theory in the expressive performance and the development of creative thinking among preparatory school students)
To achieve this, the researcher adopted on an experimental design is located in women with partial seizure experimental designs field in order to achieve the goals of the research, has sample consisted of two divisions seminars Mentzmtin in junior high school Diyala for Boys, and divided the sample of (60) called on the two groups, the first pilot of ( 30) student, and the other officer and number (30), student, and studied researchers experimental group theory TRIZ, while he studied the officer in the traditional manner, the researcher conducted a pa
This research aims to measure the discrepancy between the accounting income which is prepared according to generally accepted accounting principles and the tax income that is being prepared according to the rules and tax laws, and find out the most important differences that arise between incomes.The research found the most important to the following conclusions:1.Faces determining the tax base for companies subject to income challenges related to the weakness of the efficiency and the possibility of technical angel tax and its ability to examine the financial statements submitted to the tax administration tax.2.That the tax system in Iraq does not comply with accepted accounting principles generally accepted.The research recommends the
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Praise be to God, and may blessings and peace be upon the Messenger of God. As for:
The Noble Qur’an is the constitution of life, and a comprehensive educational approach that deals with individuals comprehensively, as it organizes worldly and eschatological life, and it is a curriculum concerned with organizing life starting with individuals and the family until the establishment of states, and from its comprehensiveness is reform, guidance and establishing boundaries. They have a disease in their hearts. They are exposed to this and are trying, by falsehood, to subjugate the Islamic world with man-made laws set by the West. Their aim is to distance people from
... Show MoreThe reaction paths of the C-C and C-H bond cleavage in the anthracene and phenanthrene aromatic molecules are studied by applying the ab-initio DFT method. It is found that the C-C bond cleavage proceeds via a singlet aromatic transition state, compelled through a disrotatoric ring opening reaction. A suprafacial H atom shift follows the transition state, leading to the formation of a methylene -CH2 and an acetylenic or allenic moiety. The calculated activation energies for anthracene range from 158.81-208.90 kcal/mol and the reaction energies from 96.106-156.976 kcal/mol. For phenanthrene, the energy values are 157.39-202.34 kcal/mol and 62.639-182.423 kcal/mol, respectively. For the C-H cleavage reactions, the calculated reaction energies
... Show MoreBackground: Nasal obstruction is common in otorhinolaryngology outpatient visitors. The diagnosis of such compliant is by history, clinical examination and diagnostic procedures. Nasal endoscopy and computerized tomography scan are common diagnostic investigations. Nasal obstruction is either anterior or posterior (nasal septal deviations, hypertrophied turbinate pathological cyst, polyps, mass etc), or postnasal obstruction (hypertrophied turbinate, adenoid hypertrophy, nasopharyngeal cyst or nasopharyngeal tumors).
Aim of study: Prospective study to compare endoscopic finding and computerized tomography of nose, paranasal sinuses and postnasal space as diagnostic methods for nasal obstruction and other nose, p
... Show MoreThe coronavirus-pandemic has a major impact on women's-mental and physical-health. Polycystic-ovary-syndrome (PCOS) has a high-predisposition to many cardiometabolic-risk factors that increase susceptibility to severe complications of COVID-19 and also exhibit an increased likelihood of subfertility. The study includes the extent of the effect of COVID-19-virus on renin-levels, glutathione-s-transferase-activity and other biochemical parameters in PCOS-women. The study included 120 samples of ladies that involved: 80 PCOS-patients, and 40 healthy-ladies. Both main groups were divided into subgroups based on COVID-19 infected or not. Blood-samples were collected from PCOS-patients in Kamal-Al-Samara Hospital, at the period between Decembe
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