Almost all thermal systems utilize some type of heat exchanger. In a lot of cases, evaporators are important for systems like organic Rankine cycle systems. Evaporators give a share in a large portion of the capital cost, and their cost is significantly attached to their size or transfer area. Open-cell metal foams with high porosity are taken into consideration to enhance thermal performance without increase the size of heat exchangers. Numerous researchers have tried to find a representation of the temperature distribution closer to reality due to the different properties between the liquid and solid phases. Evaporation heat transfer in an annular pipe of double pipe heat exchanger (DPHEX) filled with cooper foam is investigated numerically with utilizing the local thermal non-equilibrium (LTNE) model. Warm water with constant inlet conditions flows in the inner pipe while R143a is used as cooling fluid in the annular pipe. The effects of pores per inch (PPI), mass flux of R134a and copper foam porosity on solid and fluid temperatures, liquid saturation and heat transfer coefficient are analysed and illustrated. Forchheimer-extended Darcy flow model is utilized with the adopting of the two-phase mixture model (TPMM). The governing equations in two-dimensional steady state regime were written in LTNE model. These equations were discretized using the finite volume method and a MATLAB program was built to solve these equations with its initial and boundary conditions. The obtained data illustrates that LTNE effect in metal foam is important for lower porosity, lower pore density and higher mass flux. The ratio of liquid will arrive its lowest value at the outlet, and it decreases with PPI increase and it increases with porosity and mass flux increase. The mean heat transfer coefficient approximately doubled when PPI increased from 10 to 50 and it increased by 70% when porosity decreased from 0.95 to 0.85.
The historical center cities were exposed to change, which included its social and economical structures, Which led to sweeping changes in land use, causing a change in the result, in urban fabric and the physical structure and therefore to see visual. We have attracted these centers as a result of pressure from urban development and contemporary reflection of the agents of change which have been hit during the late period a development residential newly not sympathize mostly with the content of the historical and at the expense of removing large parts of the urban fabric and replace it with patterns of structural and styles of architecture has not been connected with reality. Which led to the loss of some historical and architec
... Show MoreThe article aims to study the crisis of political change from three Phases . The first focuses on the crises of political legitimacy and democratic postponement, as fundamental issues in analyzing the phenomenon of power struggle through the dialectic between the concept of historical legitimacy and institutional fragility from the beginning of statehood in 1962 to the stage of multi-partyism and the cessation of the electoral process in the 1990s. While the second focuses on the question of the monopoly of power in the post-terrorism and national reconciliation according to considerations Political, social and security measures to prolong the life of the regime and avoid the demands of political change brought about
... Show MoreThe human kidney is one of the most important organs in the human body; it performs many functions
and has a great impact on the work of the rest of the organs. Among the most important possible treatments is
dialysis, which works as an external artificial kidney, and several studies have worked to enhance the
mechanism of dialysate flow and improve the permeability of its membrane. This study introduces a new
numerical model based on previous research discussing the variations in the concentrations of sodium,
potassium, and urea in the extracellular area in the blood during hemodialysis. We simulated the differential
equations related to mass transfer diffusion and we developed the model in MATLAB Simu
What is important about this study is whether there is a relationship between the ability to balance and beating overwhelming for the Iraqi national team volleyball? The study aims to identify the percentage of the equilibrium contribution and its variables with the accuracy of the skill of beating the high spike Diagonal center (4) in the players. In the national volleyball team season (2016-2017), the researchers used the descriptive approach in the style of associative relationships to suit the problem of research. The research community included all the players specialized in the high beating of the Iraqi national team applicants in the ball The researchers concluded that the equilibrium variables contributed accurately and quickly to t
... Show MoreBMMAM Saleh, EUROPEAN ACADEMIC RESEARCH, 2016
The Iraqi and Iranian pottery has a significant role in the contemporary world pottery space, despite the fact that influences created those formulation, thus the researcher supposes that there is a relation between the potter and his environment within Iraq's environment and Iran's environment, which are similar at times and different at other times. The researcher, hence, found himself in front of a number of questions:
1- How much was the Iraqi potter inspired by the environment compared to the Iranian potter?
2- Has the Iraqi and Iranian pottery been really inspired by the environment items or there were modified metaphors?
The current research aims at (identifying the influential environmental characteristics in the Iraq