Reducing the drag force has become one of the most important concerns in the automotive industry. This study concentrated on reducing drag through use of some external modifications of passive flow control, such as vortex generators, rear under body diffuser slices and a rear wing spoiler. The study was performed at inlet velocity (V=10,20,30,40 m/s) which correspond to an incompressible car model length Reynolds numbers (Re=2.62×105, 5.23×105, 7.85×105 and 10.46×105), respectively and we studied their effect on the drag force. We also present a theoretical study finite volume method (FVM) of solving Reynolds-averaged Navier-tokes equations (RANS) using a realizable k–epsilon (k-ε) turbulence model, conducted on a car, model KIA Pride, which is popular in Iraq and Iran. All computational analysis and modifications were carried out using the ANSYS Fluent 19 computational fluid dynamics (CFD) software and SOLIDWORKS 2018 modeller. The drag coefficient of the analysed car was found to be 0.34 and the results show that the drag can be reduced up to1.73% using vortex generators, up to 3.05% using a rear wing spoiler and up to 2.47% using rear under-body diffuser slices modifications, whereas it may be reduced up to 3.8% using all previous modifications together.
Attention has recently been given to finding alternative and sustainable raw material sources for wood and metal adhesives, such as polyvinyl alcohol (PVA), corn starch (CS), arabic gum (AG), and dextrins (D). Modifying polymer dispersion using unique substances, such as modifying reactive elastomer liquid (EL) using PVA, CS, AG, or D results in sufficiently moisture-resistant adhesive joins. In the present study, the physical characteristics of EL/blended with the natural polymers PVA, CS, AG, and D, based on high-density fiberboard (HDF) wood and aluminum (Al) adhesives and coatings, were investigated and compared to those of pure EL. The EL was blended with PVA, CS, AG, or D at a ratio of 60/40 (w/w) to form EL/blends. The che
... Show MoreSingle Walled Carbon nanotubes (SWCNTs), as nano-needle structures, are good candidates as nanocarrier delivery systems that carry drug to the site of action. They are good due to their unique pharmaceutical properties. Teniposide is an anticancer drug, which is widely used, but it has a problem of low solubility. In this study, to improve the properties of carbon nanotubes, pre-functionalization of carbon nanotubes via carboxylation with strong acids has been performed and then functionalized through attaching them to the polymer and copolymer. Concurrently, a proper polymer-copolymer combination has been selected by the UV-Visible spectrometer at 880nm. It is selected based on the qualitative dispersibility analysis, the visual observa
... Show MoreMost of World nations are striving to provide the necessary needs to protect their economic properties assets against natural or abnormal disasters that may be inflicted on such property and the means that used by such countries to reduce the damages is insurance, whereas insurance as a system that collects and distributes different risks into the group thus to achieve a social symbiosis between individuals. The system works to transfer the risks from the individual to the group and then distributes the losses to all members of the group.
According to the importance of the insurance sector and the need to develop it as well as working on improving its performance, this search aims to identify the ac
... Show MoreThe aim of this research is to measure the effect of Adey- Shire model in the achievement and critical thinking of first intermediate female students in mathematics. The researcher adopted the experimental method with a post-test, the research of sample consists of (60) female students, divided into two groups with (30) students in the experimental group, that studied with Adey- Shire model, and (30) students in the control group who studied in the usual way. The two groups are equivalent in many variables. The researcher makes two tests of multiple choices, the first one is an achievement test consists (30) items and another test was for a critical thinking test with (25) items. The statistical analysis make to both tests is made with s
... Show MoreThe fluctuation properties of energy spectrum, electromagnetic transition intensities and electromagnetic moments in nucleus are investigated with realistic shell model calculations. We find that the spectral fluctuations of are consistent with the Gaussian orthogonal ensemble of random matrices. Besides, we observe a transition from an order to chaos when the excitation energy is increased and a clear quantum signature of the breaking of chaoticity when the single-particle energies are increased. The distributions of the transition intensities and of the electromagnetic moments are well described by a Porter-Thomas distribution. The statistics of electromagnetic transition intensities clearly deviate from a Porter-Thomas distribution (i
... Show MoreOne of the globalization results is (VAT) , so it is important to consider its results and impact on the tax system.
The Iraqi economy having wittnisd an acute transition period , still in need for a better care in aim to back it, especialy from the tax system.
The research is concerned with the (VAT) and its details –And for five chapters all the problomes connect are displayed .But yet the new system does not comply with the modern development and this is one of the defects of (VAT) in Iraq.
The history of (VAT)was also studied mentiorned and studied.
As a conclusion (VAT) is one of the m
... Show MoreThis research aims to identify the impact of the selective model in acquiring the concepts of Kurdish grammar among female students in the eighth grade, and to achieve the goal of research, the researcher selected the experimental design with partial control and dimensional testing; the sample includes basic schools in the Chim district of Chamal/ Sulaymaniyah and randomly selected the basic school (Maha Bad) to be the field of application of the experiment and the random drawing method was chosen: two out of three sections and the number of students of the two sections is (75) students; section (C) represents the experimental group that studied the rules according to the selective model and its number is (37) students, while secti
... Show MoreNowadays, many new technologies developed in a lot of countries. These technologies are promising in many areas such as environmental monitoring, precision agriculture as well as in animal production. The purpose of this study was to define a better understanding of how new and advanced technologies affect the agriculture and livestock sector alike. Although agriculture and animal husbandry are among the most important sectors, advanced equipment and information technology cannot be used adequately. This situation leads to low production efficiency. It is also known that there can be a significant difference in temperature between the position of the climate control sensor (room temperature) and the area occupied by the animal. This study e
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The grey system model GM(1,1) is the model of the prediction of the time series and the basis of the grey theory. This research presents the methods for estimating parameters of the grey model GM(1,1) is the accumulative method (ACC), the exponential method (EXP), modified exponential method (Mod EXP) and the Particle Swarm Optimization method (PSO). These methods were compared based on the Mean square error (MSE) and the Mean Absolute percentage error (MAPE) as a basis comparator and the simulation method was adopted for the best of the four methods, The best method was obtained and then applied to real data. This data represents the consumption rate of two types of oils a he
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