Preferred Language
Articles
/
joe-221
Numerical Investigation Using Harmonic and Transient Analysis To Rotor Dynamics
...Show More Authors

The rotor dynamics generally deals with vibration of rotating structures. For designing rotors of a high speeds, basically its important to take into account the rotor dynamics characteristics. The modeling features for rotor and bearings support flexibility are described in this paper, by taking these characteristics of rotor dynamics features into standard Finite Element Approach (FEA) model. Transient and harmonic analysis procedures have been found by ANSYS, the idea has been presented to deal with critical speed calculation. This papers shows how elements BEAM188 and COMBI214 are used to represent the shaft and bearings, the dynamic stiffness and damping coefficients of journal bearings as a matrices have been found with the variation of rotation speed of the rotor which are vary with eccentricity of journal with bearings and this eccentricity is a function of Sommerfeld number, the first critical speed analysis has been done from Campbell diagram, the critical speed it is the speed at which resonance case happen, the unbalance response analysis has been done with changing the unbalance mass then finding the maximum response of the rotor for each unbalance mass case, by Campbell diagram plot recognizing the stability of the system and find the line of un stability, above and down this line the system is stable and if speed lies on this line the system is unstable, the main reason of analysis of rotor dynamics is to help Engineers to characterize the lateral dynamics characteristics of a given design with Campbell diagram plot, can find the critical speed, the unbalance response and the system stability .

 

View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Mar 31 2017
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Investigation Desulfurization Method Using Air and Zinc Oxide/Activated Carbon Composite
...Show More Authors

In present work examined the oxidation desulfurization in batch system for model fuels with 2250 ppm sulfur content using air as the oxidant and ZnO/AC composite prepared by thermal co-precipitation method. Different factors were studied such as composite loading 1, 1.5 and 2.5 g, temperature 25 oC, 30 oC and 40 oC and reaction time 30, 45 and 60 minutes. The optimum condition is obtained by using Tauguchi experiential design for oxidation desulfurization of model fuel. the highest percent sulfur removal is about 33 at optimum conditions. The kinetic and effect of internal mass transfer were studied for oxidation desulfurization of model fuel, also an empirical kinetic model was calculated for model fuels

... Show More
View Publication Preview PDF
Publication Date
Fri Dec 01 2023
Journal Name
Baghdad Science Journal
Numerical Investigation of Physical Parameters in Cardiac Vessels as a New Medical Support Science for Complex Blood Flow Characteristics
...Show More Authors

This study proposes a mathematical approach and numerical experiment for a simple solution of cardiac blood flow to the heart's blood vessels. A mathematical model of human blood flow through arterial branches was studied and calculated using the Navier-Stokes partial differential equation with finite element analysis (FEA) approach. Furthermore, FEA is applied to the steady flow of two-dimensional viscous liquids through different geometries. The validity of the computational method is determined by comparing numerical experiments with the results of the analysis of different functions. Numerical analysis showed that the highest blood flow velocity of 1.22 cm/s occurred in the center of the vessel which tends to be laminar and is influe

... Show More
View Publication Preview PDF
Scopus (1)
Scopus Crossref
Publication Date
Wed Dec 01 2021
Journal Name
Journal Of Physics: Conference Series
Using Spatial Analysis Methods to Evaluate the Soil Contamination of Baghdad City, Iraq
...Show More Authors
Abstract<p>The current study aims to identify soil pollutants from heavy metals The study utilized 40 topsoil (5 cm) samples, which adapted and divided into seven regions lies in Baghdad governorate, included (Al-Husainya,(Hs) Al-Doura (Do), Sharie Al-Matar (SM), Al-Waziria (Wz), Nharawan (Nh), Abu Ghraib (Abu) and Al-Mahmoodyia (Mh)). Spatial distribution maps of Nickel (Ni), Manganese (Mn), Lead (Pb) and Zinc (Zn) were created for Baghdad city using Geographic Information Systems (GIS). The concentrations of four heavy metals in the soil of different area of Baghdad were measured and observed using XRF instrument. The result found highest values of Pb and Zn at the middle of the Baghdad in (Wz</p> ... Show More
View Publication
Scopus (3)
Crossref (3)
Scopus Crossref
Publication Date
Sun Jan 01 2023
Journal Name
Communications In Mathematical Biology And Neuroscience
The dynamics of a delayed ecological model with predator refuge and cannibalism
...Show More Authors

This study has contributed to understanding a delayed prey-predator system involving cannibalism. The system is assumed to use the Holling type II functional response to describe the consuming process and incorporates the predator’s refuge against the cannibalism process. The characteristics of the solution are discussed. All potential equilibrium points have been identified. All equilibrium points’ local stability analyses for all time delay values are investigated. The system exhibits a Hopf bifurcation at the coexistence equilibrium, which is further demonstrated. The center manifold and normal form theorems for functional differential equations are then used to establish the direction of Hopf bifurcation and the stability of the per

... Show More
View Publication Preview PDF
Scopus (2)
Scopus Clarivate Crossref
Publication Date
Tue May 23 2023
Journal Name
Journal Of Engineering
Numerical Simulation of Ice Melting Using the Finite Volume Method
...Show More Authors

The Aim of this paper is to investigate numerically the simulation of ice melting in one and two dimension using the cell-centered finite volume method. The mathematical model is based on the heat conduction equation associated with a fixed grid, latent heat source approach. The fully implicit time scheme is selected to represent the time discretization. The ice conductivity is chosen
to be the value of the approximated conductivity at the interface between adjacent ice and water control volumes. The predicted temperature distribution, percentage melt fraction, interface location and its velocity is compared with those obtained from the exact analytical solution. A good agreement is obtained when comparing the numerical results of one

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri May 01 2020
Journal Name
Journal Of Engineering
Parametric Study on Unconnected Piled Raft Foundation Using Numerical Modelling
...Show More Authors

Piled raft is commonly used as foundation for high rise buildings. The design concept of piled raft foundation is to minimize the number of piles, and to utilize the entire bearing capacity. High axial stresses are therefore, concentrated at the region of connection between the piles and raft. Recently, an alternative technique is proposed to disconnect the piles from the raft in a so called unconnected piled raft (UCPR) foundation, in which a compacted soil layer (cushion) beneath the raft, is usually introduced.  The piles of the new system are considered as reinforcement members for the subsoil rather than as structural members. In the current study, the behavior of unconnected piled rafts systems has been studie

... Show More
View Publication Preview PDF
Crossref (9)
Crossref
Publication Date
Sat Dec 28 2024
Journal Name
Journal Of Physical Education
The effectiveness of using interactive harmonic exercises in improving the level of some physical and motor abilities and intelligence for students aged (9-10) years
...Show More Authors

We discussed the proper preparation, directing, and implementation of physical education lessons, and clarification of the duties that fall upon the physical education teacher in addition to his physical and skill duties, which is the duty of the physical education lesson. The problem of the research lies in the fact that interactive harmonic exercises are not implemented accurately by physical education teachers because they require great experience, exceptional efforts, and accuracy in performance. The research aims to identify the level of some physical and motor abilities and intelligence among students aged (9-10) years, and to know the effect of some harmonic exercises. Interactivity at the level of some physical and motor abi

... Show More
View Publication
Crossref
Publication Date
Sat Jan 01 2011
Journal Name
Iraqi Journal Of Physics
Single Particle Level Density in a Harmonic – Oscillator Potential Well
...Show More Authors

The purpose of this paper is to study the properties of the
partial level density ( ) l g and the total level density g ( ),
numerically obtained as a l sum of ( ) l g up to 34 max l  , for
a Harmonic – Oscillator potential well. This method applied the
quantum – mechanical phase shift technique and concentrated
on the continuum region. Also a discussion of peculiarities of
quantal calculation for single particle level density of energy –
dependent potential

View Publication Preview PDF
Publication Date
Tue Dec 05 2023
Journal Name
Baghdad Science Journal
A Numerical scheme to Solve Boundary Value Problems Involving Singular Perturbation
...Show More Authors

The Wang-Ball polynomials operational matrices of the derivatives are used in this study to solve singular perturbed second-order differential equations (SPSODEs) with boundary conditions. Using the matrix of Wang-Ball polynomials, the main singular perturbation problem is converted into linear algebraic equation systems. The coefficients of the required approximate solution are obtained from the solution of this system. The residual correction approach was also used to improve an error, and the results were compared to other reported numerical methods. Several examples are used to illustrate both the reliability and usefulness of the Wang-Ball operational matrices. The Wang Ball approach has the ability to improve the outcomes by minimi

... Show More
View Publication Preview PDF
Scopus (1)
Scopus Crossref
Publication Date
Thu Feb 28 2019
Journal Name
The Open Civil Engineering Journal
Experimental Investigation of Skirt Footing Subjected to Lateral Loading
...Show More Authors
Background:

The skirt foundation is one of the powerful types of foundations to resist the lateral loads produced from natural forces, such as earthquakes and wind action, or from the type of structures, such as oil platforms and offshore wind turbines.

Objective and Methodology:

This research experimentally investigated the response of skirted footing resting on sandy soil of different states to lateral applications of loads on a small-scale physical model manufactured for this purpose. The parameters studied are the dista

... Show More
View Publication
Crossref (2)
Crossref