The aerodynamic characteristics of general three-dimensional rectangular wings are considered using non-linear interaction between two-dimensional viscous-inviscid panel method and vortex ring method. The potential flow of a two-dimensional airfoil by the pioneering Hess & Smith method was used with viscous laminar, transition and turbulent boundary layer to solve flow about complex configuration of airfoils including stalling effect. Viterna method was used to extend the aerodynamic characteristics of the specified airfoil to high angles of attacks. A modified vortex ring method was used to find the circulation values along span wise direction of the wing and then interacted with sectional circulation obtained by Kutta-Joukowsky theorem of the airfoil. The method is simple and based mainly on iterative procedure to find the wings post stall aerodynamic results. Parametric investigation was considered to give the best performance and results for the rectangular wings. Wing of NACA 0012 cross sectional airfoil was studied and compared with published experimental data for different speeds and angle of attacks. Pressure, skin friction, lift, drag, and pitching moment coefficients are presented and compared good with experimental data. The present method shows simple, quick and accurate results for rectangular wings of different cross-section airfoils.
Prostheses are used as an alternative to organs lost from the body. Flex-Foot Cheetah is considered one of the lower limb prostheses used in high-intensity activities such as running. This research focused on testing two samples of Flex-Foot Cheetah manufactured of two various materials (carbon, glass) with polyester and compare between them to find the foot with the best performance in running on the level of professional athlete. In the numerical analysis, the maximum principal stress, maximum principal elastic strain, strain energy; finally, the blade total deformation were calculated for both feet. In experimental work, the load-deflection test was done for foot to calculate the bending the results were very close to
... Show MoreThis paper aims to study the biosorption for removal of lead, cadmium, copper and arsenic ions using algae as a biosorbent. A series of experiments were carried out to obtain the breakthrough data in a fluidized bed reactor. The minimum fluidization velocities of beds were found to be 2.27 and 3.64 mm/s for mish sizes of 0.4-0.6 and 0.6-1 mm diameters, respectively. An ideal plug flow model has been adopted to characterize the fluidized bed reactor. This model has been solved numerically using MATLAB version 6.5. The results showed a well fitting with the experimental data. Different operating conditions were varied: static bed height, superficial velocity and particle diameter. The breakthrough curves were plotted for each metal. Pb2+ s
... Show MoreThe current research aims to answer the following questions: what is the substance of democracy? What is the content of a democratic society? What is the role of university professor in the democratic development of the student university in light of the new Iraqi society? In order to achieve the goals of the research, the researcher developed an a questionnaire based on literature, Iraq's draft constitution in 2005, and his experience of the field of teaching human rights and public freedoms and the teaching of democracy. It was applied to a sample of faculty members in Department of Education and Psychology / College of Education / University Baghdad for the year 20014 were obtained their answers were then processed statistically. Henc
... Show MoreThe effect of applied current on protection of carbon steel in 0.1N NaCl solution (pH=7) was investigated under flow conditions (0-0.262 m/s) for a range of temperatures (35-55°C) using rotating cylinder electrode. Various values of currents were applied to protect steel from corrosion, these were Iapp.=Icorr., Iapp.=2Icorr. and Iapp.=2.4Icorr. under stationary and flow conditions. Corrosion current was measured by weight loss method. The variation of protection potential with time and rotation velocity at various applied currents was assessed. It is found that the corrosion rate of carbon steel increases with rotation velocity and
has unstable trend with temperature. The protection current required varies with temperature and it inc
Simple, precise and economic batch and flow injection analysis (FIA)-spectrophotometric methods have been established for simultaneous determination of salbutamol sulfate (SLB) in bulk powder and pharmaceutical forms. Both methods based on diazotization coupling reaction of SLB with another drug compound (sulfadimidine) as a safe and green diazotization agent in alkaline medium. At 444 nm, the maximum absorption of the orange azo-dye product was observed. A thorough investigation of all chemical and physical factors was conducted for batch and FIA procedures to achieve high sensitivity. Under the optimized experimental variables, SLB obeys Beer’s law in the concentration range of 0.25-4 and 10-100 μg/mL with limits of detection of 0.0
... Show MoreExcessive skewness which occurs sometimes in the data is represented as an obstacle against normal distribution. So, recent studies have witnessed activity in studying the skew-normal distribution (SND) that matches the skewness data which is regarded as a special case of the normal distribution with additional skewness parameter (α), which gives more flexibility to the normal distribution. When estimating the parameters of (SND), we face the problem of the non-linear equation and by using the method of Maximum Likelihood estimation (ML) their solutions will be inaccurate and unreliable. To solve this problem, two methods can be used that are: the genetic algorithm (GA) and the iterative reweighting algorithm (IR) based on the M
... Show MoreThis work is concerned with designing two types of controllers, a PID and a Fuzzy PID, to be used
for flying and stabilizing a quadcopter. The designed controllers have been tuned, tested, and
compared using two performance indices which are the Integral Square Error (ISE) and the Integral
Absolute Error (IAE), and also some response characteristics like the rise time, overshoot, settling
time, and the steady state error. To try and test the controllers, a quadcopter mathematical model has
been developed. The model concentrated on the rotational dynamics of the quadcopter, i.e. the roll,
pitch, and yaw variables. The work has been simulated with “MATLAB”. To make testing the
simulated model and the controllers m
Reliability analysis methods are used to evaluate the safety of reinforced concrete structures by evaluating the limit state function 𝑔(𝑋𝑖). For implicit limit state function and nonlinear analysis , an advanced reliability analysis methods are needed. Monte Carlo simulation (MCS) can be used in this case however, as the number of input variables increases, the time required for MCS also increases, making it a time consuming method especially for complex problems with implicit performance functions. In such cases, MCS-based FORM (First Order Reliability Method) and Artificial Neural Network-based FORM (ANN FORM) have been proposed as alternatives. However, it is important to note that both MCS-FORM and ANN-FORM can also be time-con
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