Preferred Language
Articles
/
alkej-542
Investigation of Load and Pressure Distribution on Wing with Wake Rollup for Low Speed Aircraft
...Show More Authors

The presented work shows a preliminary analytic method for estimation of load and pressure distributions on low speed wings with flow separation and wake rollup phenomena’s. A higher order vortex panel method is coupled with the numerical lifting line theory by means of iterative procedure including models of separation and wake rollup. The computer programs are written in FORTRAN which are stable and efficient.

      The capability of the present method is investigated through a number of test cases with different types of wing sections (NACA 0012 and GA(W)-1) for different aspect ratios and angles of attack, the results include the lift and drag curves, lift and pressure distributions along the wing span taking into the  consideration the effect of the angles of attack and the aspect ratios on the wake rollup. The pressure distribution on the wings shows that there is a region of constant pressure on the upper surface of the wings near the trailing edge in the middle of the wing, also there is a region of flow separation on the upper surface of the wings. A good agreement is found between the presented work results and other from previous researches.

      These results show that the presented method is able to capture much of flow over wings feature like separation and wake rollup. 

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Dec 01 2018
Journal Name
Al-khwarizmi Engineering Journal
Experimental and Numerical Investigation for Simulation of Thermophysical Properties for Polypropylene 575 Polymer Melts in Single Screw Extruder
...Show More Authors

A numerical model for Polypropylene 575 polymer melts flow along the solid conveying screw of a single screw extruder under constant heat flux using ANSYS-FLUENT 17.2 software has been conducted. The model uses the thermophysical properties such as Viscosity, thermal conductivity, Specific heat and density of polypropylene 575 that measured as a function of temperature, and residence time data for process simulation. The numerical simulation using CFD models for single screw extruder and the polymer extrusion was analysed for parameters such as (thermal conductivity, specific heat, density and viscosity) reveals a high degree of similarity to experimental data measured. The most important outcome of this study is that geometrical, parame

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Mar 30 2021
Journal Name
Baghdad Science Journal
Solvability of Some Types for Multi-fractional Integro-Partial Differential Equation
...Show More Authors

In this article, the solvability of some proposal types of the multi-fractional integro-partial differential system has been discussed in details by using the concept of abstract Cauchy problem and certain semigroup operators and some necessary and sufficient conditions. 

View Publication Preview PDF
Scopus Clarivate Crossref
Publication Date
Thu Jan 16 2020
Journal Name
Periodicals Of Engineering And Natural Sciences
Comparison of some reliability estimation methods for Laplace distribution using simulations
...Show More Authors

In this paper, we derived an estimator of reliability function for Laplace distribution with two parameters using Bayes method with square error loss function, Jeffery’s formula and conditional probability random variable of observation. The main objective of this study is to find the efficiency of the derived Bayesian estimator compared to the maximum likelihood of this function and moment method using simulation technique by Monte Carlo method under different Laplace distribution parameters and sample sizes. The consequences have shown that Bayes estimator has been more efficient than the maximum likelihood estimator and moment estimator in all samples sizes

Publication Date
Wed Feb 01 2023
Journal Name
International Journal Of Revolution In Science And Humanity
Nonparametric Estimation of Failure Periods for Log Normal Distribution Using Bootstra
...Show More Authors

A non-parametric kernel method with Bootstrap technology was used to estimate the confidence intervals of the system failure function of the log-normal distribution trace data. These are the times of failure of the machines of the spinning department of the weaving company in Wasit Governorate. Estimating the failure function in a parametric way represented by the method of the maximum likelihood estimator (MLE). The comparison between the parametric and non-parametric methods was done by using the average of Squares Error (MES) criterion. It has been noted the efficiency of the nonparametric methods based on Bootstrap compared to the parametric method. It was also noted that the curve estimation is more realistic and appropriate for the re

... Show More
View Publication
Publication Date
Wed Mar 20 2019
Journal Name
Al-khwarizmi Engineering Journal
Natural-Convection Phenomenon from a Finned Heated Vertical Tube: Experimental Analysis
...Show More Authors

       In this work, an experimental analysis is made to predict the thermal performance of the natural-convection phenomenon from a heated vertical externally finned-tube to surrounding air through an open-ended enclosure. Two different configurations of longitudinal rectangular fin namely, continuous and interrupted are utilized with constant thickness, different numbers, and different heights are extended radially on the outer surface of a heated tube. The tube is heated electrically from inner surface with five varied power input magnitudes. The effect of fins configuration, fins number, fins height, and heat flux of the inner tube surface on the thermal performance of natural c

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Wed Feb 29 2012
Journal Name
Al-khwarizmi Engineering Journal
Natural Convection in Trapezoidal Enclosure Heated Partially from Below
...Show More Authors

Natural convection in a trapezoidal enclosure with partial heating from below and symmetrical cooling from the sides has been investigated numerically. The heating is simulated by a centrally located heat source on the bottom wall, and four different values of the dimensionless heat source length, 1/5, 2/5, 3/5, 4/5 are considered. The laminar flow field is analyzed numerically by solving the steady, two-dimensional incompressible Navier-Stokes and energy equations. The Cartesian velocity components and pressure on a collocated (non-staggered) grid are used as dependent variables in the momentum equations  discretized by finite volume method; body fitted coordinates are used to represent the trapezoidal enclosure, and grid generatio

... Show More
View Publication Preview PDF
Publication Date
Sun Oct 01 2017
Journal Name
Applied Energy
Hourly yield prediction of a double-slope solar still hybrid with rubber scrapers in low-latitude areas based on the particle swarm optimization technique
...Show More Authors

View Publication
Scopus (31)
Crossref (31)
Scopus Clarivate Crossref
Publication Date
Sun Nov 01 2020
Journal Name
Journal Of Engineering
Assessing the Influence of Moisture Damage under Repeated Load on Multilayer Interface Bond Strength of Asphalt Concrete
...Show More Authors

The performance and durability of the asphalt pavement structure mainly depend on the strength of the bonding between the layers. Such a bond is achieved through the use of an adhesive material (tack coat) to bond the asphalt layers. The main objective of this study is to evaluate the effect of moisture in conjunction with repeated traffic loads on the strength of the bonding between asphalt layers using two types of tack coats with different application rates. Using the nominal maximum size of aggregate (NMAS), the layers were graded (25/19) and (19/9.5) mm. The slabs of multilayer asphalt concrete were prepared using a roller compactor using two types of tack coats to bond between layers, namely rapid curing cut back a

... Show More
View Publication Preview PDF
Crossref (4)
Crossref
Publication Date
Fri Nov 09 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Knowledge of Prenatal Care Nurses toward Management of Toxoplasmosis in Pregnant Women
...Show More Authors

Objective: This study aims to assess the level of nurse's knowledge regarding toxoplasmosis management
in pregnant women.
Methodology: A descriptive analytic study was carried out from January 2012 to March 2012. A sample of
(70)nurses who provide prenatal care to pregnant women at primary health care centers of AL-Adala,ALHindia,AL-Askary,AL-Jamea,AL-Ansar
and AL-Salam in AL-Najaf city. The questionnaire was self-completed
and included questions on sociodemographic characteristics and toxoplasmosis aspects.
Results: The findings of the study indicated that (44.3%) of nurses have moderate level of knowledge.
(32.9%) of nurses was with age ranging from 31-36 years. (74.3%) were male. (52.9%) were secondary
graduate

... Show More
View Publication Preview PDF
Publication Date
Wed Feb 10 2016
Journal Name
Scientific Reports
Experimental demonstration on the deterministic quantum key distribution based on entangled photons
...Show More Authors

As an important resource, entanglement light source has been used in developing quantum information technologies, such as quantum key distribution(QKD). There are few experiments implementing entanglement-based deterministic QKD protocols since the security of existing protocols may be compromised in lossy channels. In this work, we report on a loss-tolerant deterministic QKD experiment which follows a modified “Ping-Pong”(PP) protocol. The experiment results demonstrate for the first time that a secure deterministic QKD session can be fulfilled in a channel with an optical loss of 9 dB, based on a telecom-band entangled photon source. This exhibits a conceivable prospect of ultilizing entanglement light source in real-life fiber-based

... Show More
View Publication
Scopus (17)
Crossref (16)
Scopus Clarivate Crossref