Preferred Language
Articles
/
XRZaU4cBVTCNdQwC6UWh
Unsteady nonlinear panel method with mixed boundary conditions
...Show More Authors

A new panel method had been developed to account for unsteady nonlinear subsonic flow. Two boundary conditions were used to solve the potential flow about complex configurations of airplanes. Dirichlet boundary condition and Neumann formulation are frequently applied to the configurations that have thick and thin surfaces respectively. Mixed boundary conditions were used in the present work to simulate the connection between thick fuselage and thin wing surfaces. The matrix of linear equations was solved every time step in a marching technique with Kelvin's theorem for the unsteady wake modeling. To make the method closer to the experimental data, a Nonlinear stripe theory which is based on a two-dimensional viscous-inviscid interaction method for each station along the wing spanwise direction and Prandtle-Glauert rule for compressibility effect were used to enhance the potential results of the method. The fast turnaround time and the ability to model arbitrary geometries is the goal of the present work. Different airplanes configurations were simulated (DLR-F4, light jet, cargo and four engine commercial airplanes). The results of pressure and forces coefficients were compared with the DLR-F4 airplane. The comparisons showed a satisfying agreement with the experimental data. The method is simple and fast as compared with other singularity methods, which may be dependent as a preliminary method to design aircrafts.

Scopus Clarivate Crossref
View Publication
Publication Date
Thu Feb 28 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Possible Options in Managing the Exchange Rate of the Iraqi Currency in light of Current Economic Conditions
...Show More Authors

The management of the exchange rate of the most important tools of economic policy because of its wide area in achieving stability and economic growth through the provision of stability in the exchange rate of the currency of the country concerned , as well as the impact and influence of money supply and then treat the economic crisis monetary and reduce the risk of currency exchange rate .For the management of the exchange rate in Iraq has passed through several stages , from installation to link to a basket of currencies to float freely , and we are dealing with in this research regard to the achievements of monetary policy , especially after the enjoyment of independence on according to the Iraqi Central Bank Law No. 56 of 2004 and Ma

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Nov 01 2019
Journal Name
Renewable Energy
Test of solar adsorption air-conditioning powered by evacuated tube collectors under the climatic conditions of Iraq
...Show More Authors

View Publication
Scopus (21)
Crossref (19)
Scopus Clarivate Crossref
Publication Date
Thu Jan 30 2020
Journal Name
Journal Of Engineering
Study Impact of Unified Power Flow Controller (UPFC) on a Transmission Line Performance under Different Loading Conditions
...Show More Authors

Now-a-days the Flexible AC Transmission Systems (FACTS) technology is very effective in improving the power flow along the transmission lines and makes the power system more flexible and controllable. This paper deals with the most robust type of FACTS devices; it’s a Unified Power Flow Controller (UPFC). Many cases have been taken to study how the system behaves in the presence and absence of the UPFC under normal and contingency conditions. The UPFC is a device that can be used to improve the bus voltage, increasing the loadability of the line and reduce the active and reactive power losses in the transmission lines, through controlling the flow of real and reactive power. Both the magnitude and the phase angle of th

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Thu Jun 01 2023
Journal Name
Iraqi Journal Of Physics
Studying the Effect of Initial Conditions and System Parameters on the Behavior of a Chaotic Duffing System
...Show More Authors

This work presents a five-period chaotic system called the Duffing system, in which the effect of changing the initial conditions and system parameters d, g and w, on the behavior of the chaotic system, is studied. This work provides a complete analysis of system properties such as time series, attractors, and Fast Fourier Transformation Spectrum (FFT). The system shows periodic behavior when the initial conditions xi and yi equal 0.8 and 0, respectively, then the system becomes quasi-chaotic when the initial conditions xi and yi equal 0 and 0, and when the system parameters d, g and w equal 0.02, 8 and 0.09. Finally, the system exhibits hyperchaotic behavior at the first two conditions, 0 and 0, and the bandwidth of the chaotic

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Thu May 18 2023
Journal Name
Journal Of Engineering
Experimental and Modeling Study of Abrasive Wear of Tungsten Carbide Drilling Bit in Wet and Dry Conditions
...Show More Authors

The results of theoretical and experimental investigations carried out to study the effect of load and relative sliding speed on the abrasive wear behavior in drilling bit teeth surfaces of an insert tungsten carbide bit have been presented. Experimentally, an apparatus for abrasive wear tests conducted on the modified ASTM-G65 was modified and fabricated to facilitate loading and measurement of wear rate for the sand/ steel wheel abrasion test, which involves two cases of contact; first is at dry sand and second is under wet condition. These tests have been carried under varied operating parameters of normal load and sliding speed. A theoretical model based upon the Archard equation has been developed for predicting wear simulation by u

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Oct 23 2013
Journal Name
Journal Of Microbiology And Biotechnology Research
Optimization of flocculation conditions of exopolysaccharide biofloculant from Azotobacter chrococcum and its potential for river water treatment
...Show More Authors

Bacteria strain H8, which produces high amount of exopolysaccharide (EPS), was isolated from soil, and identified as strain of Azotobacter chrococcum by its biochemical /physiological characteristics, EPS was extracted, partially purified and used as bioflocculant. The biochemical analysis of the partially purified EPS revealed that it was an alginate. analysis of EPS by Fourier transform infrared spectrometry (FTIR) show that the -OH groups present in bioflocculant are clearly seen at 3433.06 cm-1, the peaks attributed to the -CH3 groups present at 2916.17 cm-1 , and some distinct peaks such as carboxyl group showed strong absorption bands at 1604.66 cm-1, 1411.80 cm-1 and 1303.79 cm-1 indicate the chemical structure of alginate. The effe

... Show More
Publication Date
Sun Jul 06 2025
Journal Name
Mustansiriya University
Effects Of Some Environmental Growth Conditions On Autoaggregation Of Lactobacillus spp. Isolated From Bacterial Vaginitis Infected Females
...Show More Authors

المستودع الرقمي العراقي. مركز المعلومات الرقمية التابع لمكتبة العتبة العباسية المقدسة

View Publication
Publication Date
Mon May 11 2020
Journal Name
Baghdad Science Journal
On the Growth of Solutions of Second Order Linear Complex Differential Equations whose Coefficients Satisfy Certain Conditions
...Show More Authors

In this paper, we study the growth of solutions of the second order linear complex differential equations  insuring that any nontrivial solutions are of infinite order. It is assumed that the coefficients satisfy the extremal condition for Yang’s inequality and the extremal condition for Denjoy’s conjecture. The other condition is that one of the coefficients itself is a solution of the differential equation .

View Publication Preview PDF
Scopus Clarivate Crossref
Publication Date
Sun Dec 31 2000
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Preparation of Zeolite 4A and Studying the Operating Conditions of the Agglomeration in the Inclined Rotary Disk
...Show More Authors

View Publication Preview PDF
Publication Date
Tue Jan 01 2019
Journal Name
Plant Archives J.
Effect of planting distance on yield and yield components of four introduced upland rice varieties underaerobic conditions
...Show More Authors

Scopus (5)
Scopus