Ahmed F. Khudheyer

Al-Nahrain University · Department of Mechanical Engineering

The use of solar thermal energy for water heating reduces the consumption of fossil fuels. The thermal fluids used in solar collectors have low thermal conductivity and a reduced capacity to absorb solar radiation in the visible range, where 48% of the total radiation is found. This work aims to develop various kinds of nanofluids and assess their...

Our goal with this review paper is to provide an in-depth examination and discussion of numerous solar energy collectors of different kinds, parts, categories, and configurations through performance analysis. A detailed discussion was held regarding the impact of the functioning parameters and geometrical characteristics of the solar air collectors...

Dimples are tiny indentations on the surfaces of the body that enhance heat transfer and alter fluid flow characteristics on or within the body. Numerical investigations were conducted to analyse the heat transfer and flow characteristics in a cross-combined dimple tube in the range of Reynolds numbers from 6000 to 14000. The finite volume method r...

As the temperature of combustion gases is higher than the melting temperature of the turbine materials, cooling of turbine parts in a gas turbine engine is necessary for safe operation. Cooling methods investigated in this computational study included cooling flow losses. Film-cooling is one typically used cooling method whereby coolant is supplied...

Sustainable solar energy may be converted into usable energy with the help of solar heater heating systems. Different designs for solar heaters have been developed to improve heat transmission when used to warm air or water. The primary goal of this effort is to improve the efficiency of a solar air heater that uses natural convection. Through comp...

Computational analysis has matured into a reliable resource for foreseeing the outcome of heat absorption and honing their performance. This represents one of the most time-consuming and mind-numbing tasks to solve the computer simulations that reflect the solar air heating systems and process. Traditional solar air heaters with a single glass cove...

The numerical study of turbulent streams through such a solar air heating element leathery texture with semicircular partitioned transversal ribs imperfection was carried out. A set of governing equations represents the physical issue theoretically, and the transportation equations can be solved by using numerical simulation technique. According to...

The heat transfer performance of a new concentric tube made by plain and twisted elliptical tubes is quantitatively explored. For consistency purposes, a ring made from two plain elliptical pipes is also examined. Interior twisting oval tubes with different orientations and twisting fractions were explored. The asymmetrical flow pattern in the annu...

This article analyzes an analysis of an external solar recipient with several mass flux rates for the test and numeric thermal efficiency. The aim is to assess the thermal efficiency of the present design and analyze it. The parameters measured were entry and exit temperatures, absorbing tube temperatures, ambient temperature, and radiation solar i...

Twisted Tube heat exchangers are a form of heatingsystemwhich originated in engineering applications and became commercially accessible in the mid-1980s. It was created largely to address the drawbacks of traditional shell and tube applications.Thetwisted tube technique was largely used in single phase and condensing errands in pulp, as well as dis...

Thermally walls heat tiny twisting elliptical tubes (TOTs) to examine flow behavior and heat transmission within the pipes. Because as hydraulic fluid, fresh water is used to mimic various tubes designs, having Higher Reynolds numbers ranging from 500 to 1100 depending just on thermal thermostatic characteristics. Using known correlations and actua...

The performance of a solar collector with Fresnel type consists of an absorber with a triangular cavity is tested. In order to create a Fresnel collector, it contains an absorber through many rows of tubes, a mirror reflector by the flat cover glass with 4mm in thickness. The transient method was considered in the present article to test the therma...

A numerical study of the performance of a concentrated solar parabolic trough is presented in this article. On two parabolic trough models measuring 12.5 and 20 cm respectively, in length of focal point, the study is being carried out. In order to test the parabolic mirror, an aluminum structure was used. This paper presents a regular calculation f...

Experiments were performed on a heat exchanger of concentric double pipe through a duct of the square cross-sectional area and a circular annulus. During the experiments, water was used as a heat transfer fluid. The twisted tape had been made of stainless steel and inserts screw-tape with a similar ratio of twisting, y=4. Cold and hot water streams...

Using the sun's radiation seems to be a potential way to meet a range of modern current societal energy demands inside the future. The concentrator collectors, the most well-known sunlight focusing device, are presented in this analysis, and it's been shown that work effectively in extreme temps. ANSYS CFX is indeed a commercially available simulat...

Increasing fuel costs coupled with growing carbon pollution have prompted the globe to move to alternative energy sources in an effort to reduce carbon dioxide emissions. In addition to electricity generation, the parabolic trough collectors are implemented in a wide range of many engineering applications. In this study, we will analyze the validit...

Using solar collectors for agricultural and manufacturing purposes is a simple, cost-effective, and environmentally beneficial way to harness the power of the sun. To increase the thermodynamic efficiency of the absorber surface throughout the single and double pass solar thermal collectors, the researchers provide varied fins designs on the absorb...

The solar central tower consists of a number of flat mirrors called "Heliostats", these dual axes mirrors reflect the sun rays toward a solar receiver mounted on the top of a central tower that contains a heat transfer fluid (water). In the present study, a novel design for solar power tower technology (SPT) receiver is presented to decrease the l...

This article is a review paper deals with the case for twisted square duct. Temperature and friction properties of air flow in twisting rectangular ducts are explored using both experiments and three-dimensional computer models. Using air with a constant heat flux flow conditions, twist ratios of 11.5 and 16.5, and Reynolds numbers ranging from 200...

It can be known from heat transfer science, to enhance the heat transfer which leads to improving the thermal performance, it can change one of the two important parameters, the first parameter can be considered is the geometry which taken here in this work and the second parameter is to change the working fluid that used to work the system. Swirl...

Particularly in non-energy sources, the use of renewable radiation in industrial and commercial companies today seems to be minimal. Thus far, solar uses for process industries were limited as well as largely investigational. It is clear from a comparison of country's use of electricity in different industries that perhaps the single industry consu...

Concentrated solar power is one of the renewable energy sources in the world that can be utilized from solar energy by combining and concentrating it. In this numerical study, computer software was used to investigate the parabolic trough collector consists of a mirror and tube made of copper covered with a vacuum glass. The twisted tape made of al...

Numerical investigation for turbulent flow of nanofluid (Ethylene glycol/water-Al2O3) is carried out with a volume fraction of 0.5%, 1%, and 1.5%. The diameter of solid nanoparticles is equal to 20 nm. The range of Reynolds number in this simulation is from 6300 to 27500 through a three-dimensional steel corrugated spirally tube. For enhancement of...

This paper describes the case of combined free and forced convection heat transfer to a thermally developing air flow in a horizontal rectangular duct which has been studied experimentally for laminar internal flow. The heated surfaces were subjected to a constant heat flux while the duct short sides were kept unheated, for three cases lower, upper...

Fossil fuel has been used for electric power generation for many decades, due to CO 2 emission and its effect on climatic change, besides its massive effect on human health caused by environmental pollution and the high operation cost. As a result, researches and development studies rose to change this type of energy source to another clean source;...

In this paper, the effect of changing the thickness of the airfoils on the lift and drag coefficients and lift to drag ratio for three types of airfoils is presented. The study was done by making a 2D simulation by using the commercial software ANSYS FLUENT 2019R1. The airfoils that were selected for the simulation were the NREL S830, SG6043, and S...

Thermal efficiency of solar central receiver's energy systems is considered as an essential topic. Selective coatings in solar application also have other important factors, such as homogeneity, production speed, cycle time, as well as the minimization of the quantity of the needed chemical precursors. In this paper a new coating technique, efficie...

Using concentrated central receiver system to produce thermal power which could be converted to electricity, is a promising technique and one of the most feasible options to use clean energy instead of the fossil fuel power plants. The most important studies on the main solar central receiver thermal power plants components are represented in this...

A novel design for a central receiver prototype was manufactured with dimensions of (50*50) cm staggered configuration using copper pipes of 9.5 mm diameter was tested to produce thermal energy from solar energy, had been analyzed numerically and experimentally. central solar tower receiver prototype was manufactured and mounted at Al-Nahrain Unive...

Airflow through a circular and noncircular duct has several applications in life such as the air conditioning system, electronic devices, and food industrials. The efficiency depends greatly upon channel's cross-section and liquid media. This study has performed to investigate the effect of the geometrical duct and boundary conditions for turbulent...

The unspecified heat flux around the receiver's boundary produces a higher gradient temperature. Advanced heat transfer methods were also used to lower the pipe temperatures. This study includes a numerical simulation with a conical pin-fin arrangement for turbulent flow in parabolic trough tubes. Fins were found to enhance single-tube performance....

This article deals with effect of desecrate baffles with cutoff on solar air heater performance. Heat transfer fluid (HTF) flows through the system is air, numerically using computational fluid dynamic (CFD) technique with Reynolds from 3000 to 23000. Simulation of the present case was done through using ANSYS fluent 2019R1 with a cutoff ratio of 0...

Concentrating Solar Power (CSP) focuses sunlight in order to use the heat energy of the sun. In a central receiver system configuration, many mirrors (heliostats) individually track the sun and reflect the concentrated solar energy onto a receiver on top of a tower. The receiver contains the working fluid which is heated by the concentrated solar r...

Numerical investigation of forced convective flow in a 2-dimensional microchannel. This investigation is analyzed with nanoparticles SiO2 and water as a base fluid studying the influence of turbulence model inside multi geometrical channel (Triangular, Trapezoidal, Semi-circular, and Rectangular) by using "Finite Volume Method (FVM)". The heat flux...

This paper presents a three-dimensional numerical analysis to study the laminar forced convection heat transfer and flow characteristics of AL2O3–water Nano fluid with Solid particles less than 100 nm through a tube with 1m Length and 25 mm inner diameter and 30mm outer diameter contains circular fins with 30mm inner diameter and 50mm outer diamete...

Present paper study aerofoil with NACA2412 with Fowler and Single Slotted flaps that were used for the purpose of numerical investigation the effect of energy adder on the trace of wake behind the proposed wing at a Reynolds number of (2x105) with multi-element flap geometry having different gap, overlap distances, and different flap deflection ang...

Natural convection heat transfer from a hot surface to its surrounding enclosure is used in several technological applications especially in microelectronic systems, solar concentrators; thermal storage plants, pressurized water reactors and gas insulated electrical transmission systems. The function of the outer surface of the enclosure is to redu...

As the temperature of combustion gases is higher than the melting temperature of the turbine materials, cooling of turbine parts in a gas turbine engine is necessary for safe operation. Cooling methods investigated in this computational study included cooling flow losses. Film-cooling is one typically used cooling method whereby coolant is supplied...

As the temperature of combustion gases is higher than the melting temperature of the turbine materials, cooling of turbine parts in a gas turbine engine is necessary for safe operation. Cooling methods investigated in this computational study included cooling flow losses. Film-cooling is one typically used cooling method whereby coolant is supplied...

Theoretical and experimental studies were carried out to investigate the effects of duct velocity, fin density and tip-to-shroud clearance on the flow bypass and its impact on the pressure drop across a longitudinal aluminum fin array and its thermal performance. The clearance was varied parametrically, stating with the fully shrouded case and vari...