HAZIM JASSIM JABER AL-TALAQANI

This study numerically investigates the effect of different microchannel geometries integrated into the absorber tube on the thermal performance of a parabolic trough solar collector. Four configurations were analyzed: empty (straight pipe), circular, square, and triangular microchannels. Computational Fluid Dynamics simulations were conducted using ANSYS Fluent 19.0, adopting a Finite Volume Method with a pressure‐based solver, the SIMPLE algorithm for pressure–velocity coupling, and second‐order upwind discretization for momentum and energy equations. Simulations were performed across mass flow rates ranging from 0.25 to 1.0 kg/h, with an inlet fluid temperature of 25°C and a constant solar irradiance of 884 W/m2. The corresponding Reynolds numbers ranged approximately from 110 to 420, indicating laminar flow across all cases. Among the configurations, the triangular microchannel exhibited the best performance. At 0.25 kg/h, it achieved an outlet temperature of 101.73°C and a thermal efficiency of 85%, compared with 92°C and 37.15% in the nonchanneled base case. At 1.0 kg/h, the triangular design reached a Nusselt number of 30.48, more than double that of the baseline (14.45), indicating superior convective heat transfer. Validation against published results showed a maximum deviation of only 2.6%, confirming the accuracy of the simulation model. The findings highlight that triangular and square microchannels significantly enhance heat transfer and thermal efficiency, particularly at low flow rates, making them promising designs for advancing solar thermal energy systems.

This study is concerned with modeling and simulating clean sun energy and using it to heat water for the family using a program that depends on a set of basic parts, including (the storage tank, Flat plate collector). Where this study included temperatures ranging from 20 - 50 degrees Celsius and was found through the results, We note that the maximum temperature can reach 56 degrees Celsius between the sixth and seventh months and that the amount of heat losses reaches approximately 72KW in the seventh month and the amount of energy reaches 12KW / h.

This article examined the effect of central and longitudinal vents on the thermal behavior of the slurry compound Mineral analyzes of the used clays were performed to find the composition of the components for the clay. It was thermal characterization, In a hot cylinder fashion. The thermal transfer analysis, thermal resistance, energy saving and density fraction were extracted in a practical way. This study is important to know the effect of internal gaps on thermal conductivity during the manufacturing process, From the extracted girls, it was found that the central openings dissipate heat and reduce the conductivity, and it is less compared to the longitudinal openings.

The enhancement of heat transfer is considered as one of the important tasks for controlling the energy dissipation and consumption. In order to secure this task, it is intended to increase the efficiency of heat exchanging systems taking into account the economic and environmental considerations. This work aims to test experimentally the effect of nanoparticle concentration functionalized carbon nanotubes (FCNT Taunit M) in water and Reynolds number on the heat transfer coefficient. Three concentrations of 0.01, 0.05, 0.1 vol.% for FCNT taunit have been used. The heat transfer augmentation of the nanofluid was investigated experimentally through a test rig constructed for this purpose under constant heat flux range (16061- 22682) W/m2 at the developing region with Reynold number range 5000, 7000 and 9000 have been used. The particle size 12 nm for FCNT Taunit M. The experimental results revealed an augmentation in the Nusselt number as the volume concentration increased. The economic aspect was taken into account in this study. Pressure drop can be neglected because the increases were very small.

This numerical analysis is performed to investigate the performance of mixed convection in a vertically oriented air-cooled square cavity. One inlet/outlet placement configuration, when both the inlet and the outlet ports are located at the same bottom side, is considered. The numerical approach is based on the finite volume method integrated in an in-house formulated FORTRAN code to computationally solve the twodimensional Naiver Stock and energy equations with corresponding boundary conditions. The effect of aiding buoyancy on the flow field in a vertical downward laminar jet is examined for Richardson number (0 ≤ Ri ≤ 5) and Reynolds number (25 ≤ Re ≤ 100), with constant physical properties. The results indicate that the increase in Reynolds number increases significantly the average Nussle number; however, the increase in Richardson number slightly affect the amount of heat removal from the cavity. The fundamental nature of the resulting interaction between the buoyancy driven flow and the forced external flow demonstrated by the patterns of the streamlines and isotherms. Importantly, it is found that the placement configuration considered provides unfavorable flow and thermal distributions, and is not beneficial for heat elimination, for most of Reynolds and Richardson values.

ABSTRACT: The presented study is considered as a review related to early researches on heat transfer enhancementby means of ribs mounted in duct. One of the considerable topics used for developing highly-effective, inexpensive and light-weight heat exchangers is the heat transfer enhancement. With regard to the energy saving purposes, different techniques of heat transfer enhancement like rib tabulators, dimples, pin fin and swirl chamber were utilized in various industrial heat exchanger devices. Ribs’ attachment to flow passage is the majorly utilized technique of heat transfer enhancement. In addition, the ribs can be constructed easily and thoroughly utilized in various industries. There were various types of ribs for enhancing the heat transfer rate like circular and segmented ribs, rectangular and triangular ribs, and V-ribs (broken and simple v-ribs). The rib’s shape is of high importance in the heat transfer enhancement since it is affecting the bubbles’ separation behind the ribsas well as the amount related to turbulent kinetic energy productions. With regard to utilizing many rib types, the enhancement of the heat transfer is on the basis of height and number of ribs and many arrangements of ribs. This study is showing a review regarding various non-conventional, conventional rib shape as well as the combined effect related to ribs arrangements on the force convection heat transfer in the duct.