Publications
Energetic, economic environmental analysis for photovoltaic grid-connected systems under different climate conditions in Iraq
Jun 1, 2025Journal Cleaner Energy Systems
Publisher Elsevier B.V.
DOI 10.1016/j.cles.2025.100180
Issue 27727831
Volume 10
The present study numerically involves the feasibility analysis of environment, economic and energy of 1MWp photovoltaic (PV) system under Iraq climatic condition. The photovoltaic model is based on the monocrystal silicon solar panels with suitable inverters and other accessories. Real metrological data from NREL measurements for 21 different sites in Iraq are used to determine the best site for installing photovoltaic power plant. A sensitivity model is also developed to investigate the climate conditions e.g., Global Horizontal Irradiance (GHI), ambient temperature, altitude, absolute air mass on the capacity factors, yield factors and cost of energy for different 21 sites. Results indicated that photovoltaic power plant can be installed in different locations in Iraq due to their 3-E performances although there are some variations in these performances due to the variation in the geographical nature and metrological data. The 3-E performances outcomes indicated that the avoided of CO2 emission ranged between 2.17tCO2/ kWp and 2.55tCO2/ kWp, the levelized cost of energy ranged between 0.093USD and 0.079USD and the yield energy ranged between 1514kWh/kWp and 1745kWh/kWp, respectively. The findings display that the optimum performances are achieved in Al-Rutba city and the minimum performances are recorded in Erbil city. The other monthly energy performance ensure the yearly performance. There are similarities in the technical, economic and environment performance for some cities due to the similarities in the climatic conditions. The outcomes display that there is a direct relationship between global horizontal irradiance and technical and economic results. Other climate conditions have an effect on the results but these effects are low as compared to global horizontal irradiance. The rising in degradation rate, inflation rate and PV module price leads to rise in energy cost of plant, while the increase in the power of plant has no effect on energy cost. The conclusions display that all locations are workable for installing PV system, but Al-Rutba city is the best between them.
Conjugate local thermal nonequilibrium and non-Darcy flow inside porous enclosure: Analysis of localized heating and cooling arrangements
Dec 1, 2023Journal Heat transfer/ WILEY
Publisher John Wiley and Sons Inc
DOI 10.1002/htj.22923
Issue 26884534
Volume 52
This study covers a simulation on conjugate free convective in a porous enclosure containing a side wall thickness and partially heated and cooled from sides under the considerations of local thermal nonequilibrium (LTNE) and non-Darcy flow. Interest has been focused on how the side wall thickness and the locations of cooled and heated parts affect the effectiveness of the Nusselt number (Nu). Three different cases of localized heating and cooling locations have been implemented for the following ranges: scaled heat transfer coefficient ((Formula presented.)), wall to fluid thermal conductivity ratio ((Formula presented.)), modified Rayleigh number ((Formula presented.)), wall width ((Formula presented.)), inertial parameter ((Formula presented.)), and thermal conductivity ratio ((Formula presented.)). Outcomes show that (Formula presented.) and the locations of cooled and heated parts have remarkable impacts on all the Nusselt numbers. The intensity of LTNE region considerably relies on (Formula presented.), (Formula presented.) and (Formula presented.). The total average NuT is highly dependent on (Formula presented.), (Formula presented.), (Formula presented.), (Formula presented.), and (Formula presented.) as compared to H. The increase in (Formula presented.) leads to change of the convective mechanism to conductive mode. The rise in (Formula presented.) guides to increase Nu, where (Formula presented.) can control the flow strength. The actions of (Formula presented.) on Nuf is more evident than Nus. For low H and Kr, the size of LTNE zone is considerably affected by H as compared to Kr although Kr has a high influence on Nu. For high Kr and H, the LTNE zone has closely vanished. Findings display that the Case 2 provided the highest Nu for all tested parameters except the case of (Formula presented.). Finally, it is evident that for the problems that employed solid conduction wall with localized heating and cooling sections, Case 2 is recommended for future use in the applications that implement a porous medium and depend on free convection.
Impact of using single heated obstacle on natural convection inside porous cavity under non-Darcy flow and thermal non-equilibrium model: A comparison between horizontal and vertical heated obstacle arrangements
Apr 1, 2022Journal International Communications in Heat and Mass Transfer
Publisher Elsevier Ltd
DOI 10.1016/j.icheatmasstransfer.2022.105925
Issue 07351933
Volume 133
The current study implements a numerical investigation on natural convection inside non-Darican porous duct to analyse the actions of using a single heated obstacle attached horizontally/vertically at the heated surface under Local thermal non-equilibrium (LTNE). Importance has been given on how the heated obstacle length and its position manipulate the enhancement of natural convection. Solutions confirm that Nu is extremely depends on ratio of thermal conductivity (Kr), obstacle length (Z), obstacle position (X), modified Rayleigh number (Ra*) and inertia coefficient (Fs/Pr*) as compared to heat transfer coefficient (H). Results display that the rising in Z leads to recede free convection activity as compared to the smallest one, where Z and X have extremely impact on Nu. Results displayed that Nus, Nuf and NuT obtained for the horizontal case are higher than vertical case, which reveals a better thermal performance. Optimum enhancement in Nu has been observed when using small Z and it horizontally attached at higher place inside the duct. The density of LTNE regime is extremely reduced with rising in H, Kr and Ra* and reducing in Z and Fs/Pr*. Finally, the horizontal heated obstacle can be advised to be used in heat exchanger for techniques implementing porous media.
مميزات ومعوقات استخدام التعليم الالكتروني والتعليم الالكتروني المدمج
Sep 30, 2021Journal مجلة الغري للعلوم الاقتصادية والادارية
Publisher جامعة الكوفة/ كلية الادارة والاقتصاد
DOI -
Issue BIM-1280505
Volume 17
This study aimed to identify the concept of integrated e- learning education , its advantages and the reasons for its widespread use in education in higher education institutions and its obstacles.The descriptive method was used in this study based on previous studies and the experiences of some countries in this field ,and the study reached conclusions ,the most important of which are that there are obstacles. It faces the use of integrated e- learning education in terms of poor training of human cadres and weak infrastructure in terms of poor availability of the Internet , weak communications ,and students' inability to use modern technologies. The study also reached some recommendations that contribute to helping the use of integrated e- learning technology including the necessity of holding training courses for teaching staff alike and working to remove obstacles facing blended education in order to provide an appropriate environment that helps activate integrated e- learning
Natural convection heat transfer from a bank of orthogonal heated plates embedded in a porous medium using LTNE model: A comparison between in-line and staggered arrangements
Feb 1, 2021Journal International Journal of Thermal Sciences
Publisher Elsevier Masson s.r.l.
DOI 10.1016/j.ijthermalsci.2020.106692
Issue 12900729
Volume 160
This study numerically presents the characteristics of natural convection induced by a bank of orthogonal heated plates instilled inside porous cavity using the assumption of local thermal non-equilibrium (LTNE) and non-Darcian conditions. In-line and staggered arrangements of heated sections have been investigated for the purpose of comparison. Attention has been given on how the arrangement of heated sections affects the performance of heat transfer for various related parameters. Numerical solutions demonstrated that the average Nusselt number (Nu) is robustly depends on thermal conductivity ratio (Kr), inertia parameter (Fs/Pr*) and modified Rayleigh number (Ra*) in comparison with scaled heat transfer coefficient (H). The results show that the solid Nusselt number (Nus) is lower than fluid Nusselt number (Nuf) for same value of Fs/Pr* owing to Fs/Pr* is directly affected on the fluid phase. Although Kr has a considerable effect on all Nu in comparison with H, H has a substantial impact on the strength of LTNE zone as compared to Kr, particularly for smaller Kr and H. The medium inside the enclosure nearly reaches the equilibrium condition for larger values of H and Kr. Most importantly, the results indicated that the performance of in-line arrangement is better than that obtained with staggered ones. Therefore, in-line arrangement can be recommended to be employed in manufacturing flat heat exchangers for applications involving porous media under natural convection case.
Effect of suction or blowing on velocity and temperature distribution of flow over a flat plate
Dec 30, 2020Journal Materials Today: Proceedings
Publisher Elsevier Ltd
DOI 10.1016/j.matpr.2020.12.735
Issue 22147853
Volume 42
In this paper, laminar, incompressible flow with constant pressure gradient and constant wall temperature over a flat plate for several values of fluid suction and blowing parameters at ß=-0.1978, m=-0.09 and ß=0.66, m=0.5 respectively were studied numerically. The governing nonlinear partial differential equations are transformed to ordinary differential equations by using a similarity variable and then solved numerically adopting Runge-Kutta integration method. Effects of continuous suction and blowing with very low ratio of constant velocity to free stream neglecting the mass transfer on the velocity, temperature profiles and skin friction are presented. The results indicated that the skin friction factor is increased with increase the value of the suction for given Reynolds number. In order to reduce the skin friction, the laminar flow and avoid transition the blowing have been applied. The effect of fluid blowing parameter on velocity profile in hydrodynamic boundary layer are the certain incidence angles. Results show that the hydrodynamic boundary layer thickness is increased due to the blowing. It can be noted that the delaying separation is led to increase of the maximum lift. It was observed that increasing the maximum lift by maintain laminar flow to avoid transition and delaying separation to reduce skin friction is existing by suitable magnitude of suction or blowing. It is concluded that the skin friction is decreasing due to apply the blowing over a flat plate.
Analysis of effects of Thermal Non-Equilibrium and Non-Darcy Flow on Natural Convection in a Square Porous Enclosure Provided with a Heated L Shape Plate
Sep 1, 2020Journal International Journal of Mechanical Sciences
Publisher Elsevier Ltd
DOI 10.1016/j.ijmecsci.2020.105704
Issue 00207403
Volume 181
This work involves a study on the convective heat transfer over a two perpendicular plates embedded inside a square porous cavity using non-Darcian flow and Local Thermal Non-Equilibrium (LTNE) assumptions. The problem has been assumed to be steady and two-dimensional coordinates. For non-Darcy flow, the effects of inertia and boundary layer have been included. Finite volume method has been used to discretize and solve the governing equations. The results show that the total average Nusselt number (NuT) is a strong function of modified Rayleigh number (Ra*) and inertia parameter (Fs/Pr*). For a fixed Fs/Pr*, the fluid Nusselt number (Nuf) has been found higher than the solid Nusselt number (Nus). The results also demonstrated that the thermal conductivity ratio (Kr) has a significant impact on all average Nusselt numbers compared to the scaled heat transfer coefficient (H). However, H has a considerable influence on the intensity of LTNE region in comparison to Kr , especially for their lower values. The size and the power of LTNE region are increased with increasing in Ra* and decreasing in Fs/Pr*. For higher Kr and H, the medium inside cavity be close to the thermal equilibrium condition. The results show that the effect of Kr on all Nu is comprehensive, whereas the effect of H is limited to Nus and hence, the behaviour of NuT is similar to the behaviour of Nuf. As Kr is increased, NuT becomes very close to Nuf. Finally, the obtained results have been summarised by developing a correlation of NuT which can be used in engineering design.