Anbar Journal of Engineering Sciences

In this study, thermal-hydraulic performance of a confined slot jet impingement with Al2O3-water nanofluid has been numerically investigated over Reynolds number ranges of 100-1000. Two
triangular ribs are mounted at a heated target wall; one rib located on the right side of the stagnation point and another one located on left side of the stagnation point. The governing momentum, continuity and energy equations in the body-fitted coordinates terms are solved using the
finite volume method and determined iteratively based on SIMPLE algorithm. In this study, effects of Reynolds number, rib height and rib location on the thermal and flow characteristics
have been displayed and discussed. Numerical results show an increase in the average Nusselt
number and pressure drop when Reynolds number and rib height increases. In addition, the
pressure drop and average Nusselt number increases with decrease the space between the stagnation point and rib. The maximum enhancement of the average Nusselt number is up to 39 %
at Reynolds number of 1000, the rib height of 0.3, rib location of 2 and nanoparticles volume
fraction of 4%. The best thermal-hydraulic performance of the impinging jet can be obtained
when the rib height of 0.2 and rib location of 2 from the stagnation point with 4% nanoparticles
volume fraction.

The present paper addresses the numerical study of non-Darcy laminar forced convection
flows in a pipe partially filled with grooved metallic foam attached in the inner pipe wall,
which is subjected to a constant heat flux. Computations are carried out for nine different
dimensions of grooves with different Reynolds numbers namely; (250 ≤ Re ≤ 2000) and
their influences on the fluid flow and heat transfer are discussed. The governing and energy
equations are solved using the finite volume method (FVM) with temperature-dependent
water properties. The novelty of this work is developing of a new design for the metallic
foam, which has not studied previously yet. It is observed that the two helical grooves with
two pitches increase the Nu around 5.23% and decrease the pumping power nearly 12%. It
is also showed a reduction in the amount of material required for manufacturing the heat
exchanger, which leads to a decline in the weight of the system 8.29%

In this study, a numerical investigation on the thermo-hydraulic performance of the
double pipe heat exchanger into heat transfer by different shapes of fins on the outer
surface for the inner tube as extended surfaces. The inner and outer diameters of the
inner pipe were (16.05 mm), (19.05 mm) respectively, and (34.1 mm), (38.1 mm) for the
outer tube. The length of the heat exchanger was (1000 mm). Hot and cold water were
used as the working fluid, where the hot water flows inside of the inner one in counter
flow with the cold water which flows in the annulus. The inlet temperature for the hot
water is (75 OC) while it is (30 OC) for the cold. The hot fluid flows at constant rate
which is (0.1kg/s) while the cold is varied from (0.1 kg/s to 0.2 kg/s).The study was
perform using the known commercial CFD package (ANSYS – FLUNET 15) .The
results shows that both (rectangular and triangular) fins enhances the heat transfer
coefficient compare with the conventional plain tube .The rectangular fins presents an
heat transfer enhancement ratio of (61% to 74%). Using of extended surfaces present a
good result in saving energy by enhancing the performance of the double pipe heat
exchangers used in petroleum industry.

This study focuses on improving the thermal comfort in Mosques in Iraq. Omar bin Abdul Aziz
Mosque in Baghdad is taken as a case study. In general, the weather in Baghdad is hot- dry climate
during the summer. the study was conducted at the time of noon prayer on Friday where the
maximum number of people can be obtained inside the Mosque about 500 worshipers and severe
environmental conditions. Numerical methods (CFD) are used for the simulation utilizing the
package of ANSYS (FLUENT V. 18). As the results depending on the number of elements, 4
millions elements are used for dividing the physical domain. Thermal comfort was assessed by
finding the values of the predicted mean vote (PMV), predicted percentage of dissatisfied (PPD),
and ASHRAE standard-55. The adaptive redistribution of the air conditioning device strategy at
five cases is used to obtain the best thermal comfort. Moreover, changing the angle of air intake of
space by changing the angle inclination of the access blade at three different angles of 0o, 7.5o and
15o degree, and studying its effect on the thermal comfort in breathing level. The four case is the
best in terms of thermal comfort when the angle of intake air at 0o.when the PMV was 0.35 and
PPD is 7.5, which is lower than the original state. The improving percentage of PPD is 10 % and
PMV 14 %.

ORE addresses various kinds of losses associated with manufacturing system which can be
targeted for initiating improvements. Evaluating ORE will is helpful to the decision maker(s) for
further analysis and continually improves the performance of the resources. Overall Resource
Effectiveness (ORE) encompasses seven factors are; performance, quality rate, readiness,
changeover efficiency, availability of material and availability of manpower. In this research Job
shop production of General Company for hydraulic industries, with focus on Damper and Tasks
Factory (DTF)is tested as a case study for two of the most customer demand rear dampers
(Samaned and Nissan). Data are collected and analyzed for years 2016-2017 to evaluate of ORE
values. Results show that process performance factor among other seven factors have the less
value causing the highest loss in ORE decrease. Where the highest ORE value is (58.6%) for
Nissan and (69.3) for Samaned rare production. Also, time loss due to set up time is detected
where it ranges from 3% to about 13% per month for the above mentioned two tested dampers.
Results are generated employing Minitab Version 17, Quality Companion Version 3 soft wares. It
is recommended to introduce SMED (Single Minute Exchange of Dies) concept that could
decrease losses in set up time .Also improvements in maintenance programs are vital, and above
all improving process performance values is essential by employing lean manufacturing that
result in fast outcomes ,and TQM process improvement strategy for long term outcomes these
two process performance strategies may enhance ORE values therefore, decrease losses, and
consequently increase quality and productivity.

A gradual change in the state and properties of the oil transformer due to
aging, which generally leads to break down. Aging of the mineral oil cause permanent
harmful change of the ability insulation system.
Aging of the mineral oil and water content of paper insulation are
simulated at the laboratory by putting the samples of the oil and pieces of insulation
paper in a rig (transformer manufactured) and exposed to different temperatures
(20Co
, 40Co
, 60Co
, 80Co
) for specific durations of time to analysis and improve the
performance of the transformer.
In this research, the electrical and physical characteristics for the mineral oil
and paper insulation have been studied and then repeated by the addition of different
concentration of Nanoparticales (ZnO) (0.01, 0.03, 0.05, 0.07)gm/ml then compared
with the electrical properties of the pure mineral oil and paper insulation without (ZnO)
nanoparticales

This paper study the effect of paving runway and atmospheric conditions on airplane takeoff
distance and time with roll stage and air stage. Two airplane types DC-9 and Boeing 747-400
were considered for different atmospheric condition with different weight by using time step
integration technique and Krenkel and Salzman assumed that the variation of thrust and
velocity create the balance of forces equations on the aircraft during its takeoff run. The air
temperature and airplane weight and runway paving are the most effected parameters on
takeoff time and distance. The runway paving consideration are very important for airport
design and runway construction to minimums fuel consumption during takeoff

The forced deflections of simply supported cracked composite beams are investigated when subjected to moving dynamic load. The crack is modeled as rotational spring and used in the formulation of the composite beam with a moving load in sinusoid wave. The numerical solution is
satisfactory compared to the experimental results. The effects of crack depth and crack positions
at different load speed are studied. The results show that the forced deflection increased with
increasing the speed ratio and crack depth

Materials selection is a multi-criteria decision-making (MCDM) problems because the large number of factors affecting on decision making. The best choice of available material is critical to the
competitiveness and success of the manufacturing organisation. The analytical hierarchy process
(AHP) is an important tool to solve MCDM problems. The choosing process of suitable material
(such as a refrigerant fluid) for the Air Condition System (ACS) is faced with challenges such as
lack of a systematic approach in setting the optimal performance in terms of its impact on the
environment and operation. Selecting process for the one refrigerant from a range suitable of
suitable refrigerant is complex process. The study presents a comparative performance analysis
of ACS for using four alternative refrigerants R290, R410, R404 and R22. Then, one of these suitable refrigerant is selected. The comparison is based on three criteria system operation, environment and maintenance.
Novels ACS performance assessment model is proposed based on an analytical hierarchy process
(AHP). The model is based on two main criteria of ACS, quantitative criteria, cooling capacity
(CC), coefficient of performance (COP), etc.).
And qualitative criteria (Ozone Depletion Potential (ODP), Global Warming Potential (GWP) and
maintenance cost (MC)). It is necessary to look for new technique help decision making to select
alternative refrigerants, to fulfill the goals of the international protocols (Montreal and Kyoto)
and optimum operation, to satisfy the growing worldwide demand, in addition the increase outdoor temperature in some countries.
This study provides a developed methodology for evaluating ACS performance. Moreover, it helps
to select a robust decision. The results obtained from AHP process that the best rank of the suitable refrigerant was R404 (0.3763) followed by R22 (0.3657) and so on for the other. Therefore,
the proposed methodology can help the decision maker to select the best alternative for both
criteria (qualitative and quantitative) in complex selecting process.

This paper offers the linear analysis of the static behavior of two directional functionally graded
(2D-FG) cylindrical panels under the effect of internal symmetric loads. The mechanical
properties of the cylindrical panel are given to be changed simultaneously through the thickness
and longitudinal directions as a function to the volume fraction of the constituents by a simple
power-law distribution. Based on Sander’s first order shear deformation shell theory (FSDT), the
equations of motion for (2D-FG) panels are derived using the principle of minimum total
potential energy (MPE). The finite element method (FEM) as an effective numerical tool is
utilized to solve the equations of motion. The model has been compared with those available in
the literature and it observed good correspondence. The influences of the material variation
along the thickness and longitudinal directions, geometrical parameters, boundary conditions
and load parameters on the panel deformation are studied in detail.

Lean is a powerful process improvement strategy that is widely used to improve different
processes. In this Paper, lean manufacturing as process improvement strategy is employed
throughout relative tools and techniques as VSM, 5S, and standard work. These tools and
techniques are employed to identify measure and evaluate processes. Job shop production of
General Company for hydraulic industries, with focus on Damper and Tasks Factory (DTF) is
tested as a case study for the two most customer demanded rear dampers of Samaned and Nissan.
Data analysis shows different issues Work-In-Process (WIP) issues causing under/ over and
production discrepancy. Improvements are introduced throughout WIP developments and 5S
techniques. Results show that these developments may result in reduction of 65% WIP waiting
time for Nissan and 58% of Samaned rear dampers. An increase in Overall Work Efficiency (OWE)
could result in by 10% for Nissan, and 2% for Samaned dampers While 5S may result in
improvements by 50% production processes and 43% assembly processes for Set in order , and
by 33% in both production and assembly processes for standardize. Data where analyzed and
further results are generated using software's are; Minitab Version 17, Quality Companion
Version 3, and Edraw-Max Version 7.