Al-Qadisiyah Journal for Engineering Sciences

Abstract This work examines the two-dimensional continuous flow of a Casson-Williamson fluid over a stretched surface under a Darcy-Forchheimer permeable medium. Several elements can affect the flow, including Joule heating, radiation, chemical reactions, thermal sources, electric field influences, and magnetic field influences. Nonlinear partial differential equations articulate the fundamental equations governing the system's dynamics in this physical model. We simplify these equations to a system of nonlinear ordinary differential equations by applying requisite changes. The Keller Box technique is utilized to simplify this collection of ordinary differential equations. Velocity, temperature and concentration graphs are plotted. The velocity profiles decline with a rise in the Casson parameter, magnetic parameter, porous parameter, Weissenberg number, and velocity slip parameter. Still, the electric field parameter diminishes when the speed slip constraint is enhanced. This study primarily examines several local properties, including the skin resistance coefficient, the Nusselt number, and the Sherwood numbers. We compare our results with the current literature by computing the skin friction coefficient for different inputs of the Casson factor. Prior studies have yielded results that are fairly congruent with this one.

Abstract This work deals with the investigation of radiation models for combustion spray. The n-pentane fuel C5h12 is used for chemical reactions with the air. The main objective of these simulations is to compare the experimental data and radiation models for spray combustion and to select the best radiation model. The model is used to interpret the structure and properties of the prediction for spray combustion. The simulated cases are carried out using Ansys Fluent. The mixture fracture probability density function is used to evaluate the non-premixed combustion of vaporized fuel droplets. The Radiation models (p1, discrete coordinate, surface to surface, and Roseland) are used to predict local properties in two dimensions. The results of the numerical simulation are compared with the experimental data. The results showed that the p1 radiation model provides good results through temperature, turbulence kinetic energy, and velocity components.

Abstract In this work, a system of a heat pipe is implemented to improve the performance of flat plate solar collector. The model is represented by square shape portion of the evaporator section of wicked heat pipe with a constant total length of 510 mm, and the evaporator section inclined by an angle of 30^o. In this models the evaporator, adiabatic and condenser lengths are 140mm, 140mm, and 230mm respectively. The omitted energies from sunlight simulator are 200, 400, 600, 800 and 1000 W/m² which is close to the normal solar energy in Iraq. The working fluid for all models is water with fill charge ratio of 240%. The efficiency of the solar collector is investigated with three values of condenser inlet water temperatures, namely (12, 16 and 20^o C). The numerical result showed an optimum volume flow rate of cooling water in condenser at which the efficiency of collector is a maximum. This optimum agree well with the ASHRAE standard volume of flow rate for conventional tasting for flat plate solar collector. When the radiation incident increases the thermal resistance of wicked heat pipe is decreases, where the heat transfer from the evaporator to condenser increases. The numerical results showed the performance of solar collector with square shape evaporator greater than other types of evaporator as a ratio 15 %.

Abstract One dimensional analysis of heat transfer from fin is simple when only heat transfer by convection from fin surface. However, in some cases heat transfers by combined phenomena (convection and radiation), this makes the governing differential equation of heat transfer non-linear and the analytical solution becomes hard to solve. This paper uses an approximate method to solve the problem with high-quality results based on finite element technique. The method can be used for different types of fins and for different shapes. The results show suitable agreement between semi-exact solution and numerical solution

Abstract Radon gas is unstable, it releases energy by emitting alpha particles, and is soluble in water and is often found in the ground water. Decays of radon emits alpha particles and beta particles. The energy released from these decay products results in damage to biological tissues which may lead to cancer. The health consequences of radon are well documented. Measurements of natural radioactivity in soil and ground water have been studied. Radionuclides present in soil include Ra226 , Th232 , and K40. Gamma rays dose depends on the geological and geographical and appears in many levels in soils , the knowledge of gamma distribution in soils and well water play important role for protection against radiation. Drilling company drills 4 wells in Babylon Institute. Doses, statistical information's about these wells are studied, also contours between real and estimated values are drawn. Testes are done in Babylon Environmental Office