This study examines experimentally the performance of a horizontal triple concentric tube heat exchanger TCTHE made of copper metal using water as cooling fluid and oil-40 as hot fluid. Hot fluid enters the inner annular tube of the TCTHE in a direction at a temperature of 50, 60 and 70 oC and a flow rate of 20 l/hr. On the other hand, the cooling fluid enters the inner tube and the outer annular tube in the reverse direction (counter current flow) at a temperature of 25 oC and flow rates of 10, 15, 20, 25, 30 and 35 l/hr. The TCTHE is composed of three copper tubes with outer diameters of 34.925 mm, 22.25 mm, and 9.525 mm, and thicknesses of 1.27 mm, 1.143 mm, and 0.762 mm, respectively. TCTHE tube's length was 670 mm. Nusselt number, overall heat transfer coefficient, convective heat transfer coefficient (CHTC), friction factor and pressure drop were measured from the obtained experimental results and plotted in graphs against Reynold number and volumetric flow rate of water. These parameters appeared good results in the cooling process. Nusselt numbers increased linearly with DIW flow rate for both C1 and C2 reaching maximum values of 38.25 and 14.64 respectively. CHTC increased linearly with the DIW flow rate for both C1 and C2 reaching maximum values of 2934.3 and 871.7 respectively. Overall heat transfer coefficient of DIW reached maximum values of 296.36 and 251.4 at 35 l/hr for C1 and C2, respectively. Friction factor DIW in C1 and C2 decreased with the volumetric flow rate increases, reaching minimum values of 0.04 and 0.25 respectively. Pressure drop of DIW increased linearly with flow rate reaching maximum values of 81.4 and 4.31 for C1 and C2 respectively. This in turn leads to reduced TCTHE length and size leading to a decrease in the construction cost of the heat exchanger.
This research presents a numerical study to simulate the heat transfer by forced convection as a result of fluid flow inside channel’s with one-sided semicircular sections and fully filled with porous media. The study assumes that the fluid were Laminar , Steady , Incompressible and inlet Temperature was less than Isotherm temperature of a Semicircular sections .Finite difference techniques were used to present the governing equations (Momentum, Energy and Continuity). Elliptical Grid is Generated using Poisson’s equations . The Algebraic equations were solved numerically by using (LSOR (.This research studied the effect of changing the channel shapes on fluid flow and heat transfer in two cases ,the first: cha
... Show MoreThe Purpose of this study is mainly to improve the competitive position of products economic units using technique target cost and method reverse engineering and through the application of technique and style on one of the public sector companies (general company for vegetable oils) which are important in the detection of prices accepted in the market for items similar products and processing the problem of high cost which attract managerial and technical leadership to the weakness that need to be improved through the introduction of new innovative solutions which make appropriate change to satisfy the needs of consumers in a cheaper way to affect the decisions of private customer to buy , especially of purchase private economic units to
... Show MoreProfit is a goal sought by all banks because it brings them income and guarantees them survival and continuity, and on the other hand, facing commitments without financial crisis. Hence the idea of research in his quest to build scientific tools and means that can help bank management in particular, investors, lenders and others to predict financial failure and to detect early financial failures. The research has produced a number of conclusions, the most important of which is that all Islamic banks sample a safe case of financial failure under the Altman model, while according to the Springate model all Islamic banks sample a search for a financial failure except the Islamic Bank of Noor Iraq for Investment and Finance )BINI(. A
... Show MoreThe simulation have been made for 3D flow structure and heat transfer with and without
longitudinal riblet upstream of leading edge vane endwall junction of first stage nozzle guide vane .The research explores concept of weakening the secondary flows and reducing their harmful effects.Numerical investigation involved examination of the secondary flows ,velocity and heat transfer rates by solving the governing equations (continuity, Navier -stokes and energy equations ) using the known package FLUENT version (12.1).The governing equations were solved for three dimentional, turbulent flowe, incompressible with an appropriate turbulent model (k-ω,SST) .The numerical solution was carried out for 25 mode
... Show MoreInformation pollution is regarded as a big problem facing journalists working in the editing section, whereby journalistic materials face such pollution through their way across the editing pyramid. This research is an attempt to define the concept of journalistic information pollution, and what are the causes and sources of this pollution. The research applied the descriptive research method to achieve its objectives. A questionnaire was used to collect data. The findings indicate that journalists are aware of the existence of information pollution in journalism, and this pollution has its causes and resources.
The research discusses with organizational spirituality and its implications on the organizational performance in the General Company for Food Industries in Abu Ghraib (Baghdad). The aim of the research was to determine the contribution of organizational spirituality in the organizational performance of the surveyed company. In order to achieve the objectives of the research، two main hypotheses were adopted. Several sub-hypotheses centered on the relationship between organizational spirituality and organizational performance in terms of its dimensions (Meaning work، self-esteem، community affiliation،
... Show MoreAn overall mathematical model for copper pipe corrosion in flowing water was derived based on mass transfer fundamentals where we introduced the effects of boundary layer velocity, bulk flow velocity and the surface oxide protective film on the corrosion rate. A set of experiments were conducted in a straight 10mm diameter copper pipe, flow of water include six velocities of maximum value 7.33m/sec at 200C and 350C. The good agreement between the calculated and experimental corrosion rate values were achieved , the agreement reached 92% .
Source, sedimentation, coagulation, flocculation, filter, and tank are parts of a water treatment plant. As a result, some issues threaten the process and affect the drinking water quality, which is required to provide clean drinking water according to special standards and international and local specifications, determined by laboratory results from physical, chemical, and biological tests. In order to keep the water safe for drinking, it is necessary to analyze the risks and assess the pollution that occurs in every part of the plant. The method is carried out in a common way, which is monitoring through laboratory tests, and it is among the standards of the global and local health regulators
The significant shortage of usable water resources necessitated the creation of safe and non-polluting ways to sterilize water and rehabilitate it for use. The aim of the present study was to examine the ability of using a gliding arc discharge to inactivate bacteria in water. Three types of Bacteria satisfactory were used to pollute water which are Escherichia coli (Gram-negative), Staphylococcus aurous (Gram-positive) and salmonella (Gram-negative). A DC power supply 12V at 100 Hz frequency was employed to produce plasma. pH of water is measured gradually during the plasma treatment process. Contaminated water treated by gliding arc discharge at steadying the gas flow rate (1.5 l/mi