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A 2-D plane, steady, incompressible, turbulent flow field developed by naturalconvection inside inclined solar chimney at different inclination angles rangingfrom (30o to 90o), heat fluxes from (100 W/m² to 500 W/m²) and chimneythickness(0.1, 0.2 m) chimney is investigated numerically. It is found thatmaximum air temperature and maximum volume flow rate was 101.7oC, 306.3m³/h respectively at heat flux,500 W/m2; inclination angle; 90o and chimneythickness; 0.2m. Maximum outlet air velocity was 0.488 m/s at chimneythickness; 0.1m, heat flux; 500 W/m2; and inclination angle; 90o. Increase in heatflux, inclination angle and chimney thickness leads to increasing of volume flowrate. Increase in chimney cross-sectional area leads to decrease in air velocity andincrease in volume flow rate

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Transient thermal stresses in pipe wall due to coolant turbulent flowthrough pipe are investigated in this study with transient isothermal hot boundaryin the external pipe radius. Three Different values of Reynolds are tested (3000,5000 and 8000). Finite volume method was used to calculate the velocities andtemperatures fields in the working fluid (air). Thermal resistance method was usedto calculate the transient temperature distribution in the pipe wall and then thetransient thermal stresses were calculated. Minimum thermal stress was locatednearly in the mid plane of the pipe.

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The Two-dimension ramp inlet flow field was studied with typical mode operations.Euler equations were used for solution with no special treatment required. In this work asolution algorithm based on finite difference MacCormack’s technique was developed tosolve mixed subsonic-supersonic flow problem through the external shock diffusers(ramp inlet) and it is found to be converge for supercritical and critical inlet operation.

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In this study the freezing of foods was studied numerically and experimentally.Different kinds of foods have been studied numerically (Meat, Broccoli, Perch andBanana), while the experimental work is applied to meat only. In numerical solutionenthalpy transformation method is used to transfer the energy equation into a nonlinearequation with a single dependent variable E (enthalpy). The discretization ofenergy equation in three dimensions was solved with phase change problememploying the control-volume finite-difference. The numerical results of the enthalpymethod were compared with experimental results and were satisfactory. The freezingprocess of foods differs from one to other due to thermal property differences, watercontent and freezing point. Low water content leads to smooth cooling rate and shortconstant temperature region while high water content leads to long constanttemperature region.

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Axi-symmetric, steady, incompressible, turbulent flow field developed by natural convection inside power plant solar chimney is investigated numerically using finite volume method. Navier-Stockes with energy equation is solved to achieve velocity components and temperature distribution inside solar chimney. To complete the thermal analysis, conduction through upper glass wall, chimney concrete wall and floor ground were investigated to calculate temperature distribution through theses walls. A standard turbulence model associated with lawss of the wall along solid boundaries was used. Special arrangement for mesh was used to deal with complicated shape of the domain. The main studied parameters are solar collector diameter, kinds of ground, periphery heights and solar intensity radiation. This study was compared with previous available experimental study and there is acceptable agreement. The performance of the solar chimney was examined through maximum air velocity in the tower inlet and maximum temperature in the ground floor. The final optimization parameters are defined within studied ranges.

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Experimental and numerical study of fluid flow and heat transfer in microchannel airflowis investigated. The study covers changing the cooling of micro-channel for the velocities and heater powers. The dimensions of the microchannel were, length = 0.1m, width = 0.001m, height = 0.0005 m. The experimental and numerical results were compared with the previous paper for velocities up to 20 m/s and heater powers up to 5 W and the comparison was acceptable. In this paper, the results were extended numerically for velocities up to 60 m/s. The numerical solution used finite volume (SIMPLE algorithm) to solve Navier Stokes equations (continuity, momentum and energy). The results show that the heat transfer coefficient increases up to 220 W/m2oC for velocity 60 m/s.

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A numerical study of mixed convection cooling of heat dissipating electronic component, located in a rectangular enclosure, and cooled by an external through flow of air is carried out. A conjugate problem is solved by primitive variables method, describing the flow and thermal fields in air. The interaction between the components is of interest here, depending on their relative placement in the enclosure, and different configuration are considered. For Re=100 laminar, steady flow is predicted for up to Gr/Re2 =25 according to head source location in the enclosure. The mixed convection regime, where the buoyancy effects are comparable to the forced flow, occurs at values of Gr/Re2 between 0.01 and 25 . the results are of values in search for suitable placement of electronic components in an enclosed region for an effective heat removal. In general, it appears that the location of the source on the left vertical wall is the most favorable in terms of cooling. Laminar results are predicted up for up to Gr= 2.5 *105 for all configurations studied.

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Theoretical and experimental studies were conducted on forced draftwater cooling tower. In such towers, the heat and mass transfer take placefrom the hot water to the bulk air, which passes through the tower. Thetheoretical study includes two parts, the first part describes the numericalsolution for the water cooling tower governing equations, a two dimension airmomentum equation (Navier-Stocks equations) and air enthalpy equation(energy equation), moisture content and water enthalpy equation. The effectof turbulence was simulated using the k-ε model. The packing-air resistance isdescribed and added to the air momentum equation in y-direction only. Thesecond part highlights the use of three different packing types. This includesthe use of a ceramic packing in two different heights (0.66, 0.48m) in additionto an aluminum packing. A simple comparison between all the above types ofpacking behavior is conducted. The experimental study was conducted usingHilton water cooling tower, which is a counter flow type. The variation inmany variables, which affect the tower efficiency, are described in this part ofthe research including variation heating loads, entering water mass flow ratesand incoming air volume flow rates. The flow field velocity vector for airthrough the tower is plotted, and an accurate behavior of both air and waterproperties was found.

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A computational procedure was conducted in (3x3x3 m) rooms and in a full–scale model building to study the effect of supply temperature on the roomflow patterns in mechanically ventilated spaces. The procedure is based on thesolution in finite-volume form of 3D equation for the conservation of mass,momentum, energy, kinetic energy and dissipation rate. Effect of buoyancy onthe turbulence model has been included. The results are shown to be inreasonable agreement with experimental data.

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In this work, a three-dimensional primitive variable of supersonic flow overmissiles was computed based on finite difference computational fluid dynamicmethods. The problem was considered is to deal with external, inviscid, compressiblesupersonic- flow over three-dimensional missiles with and without canard. Eulerequations were solved using time-marching MacCormack’s explicit technique. Theflow conditions are taken at sea level and Mach number was tested up to 4.0. To dealwith complex shape of missiles the so-called “body fitted coordinate system” wasconsidered and the algebraic and elliptic methods were used to generate grids overmissiles. The number of iterations and the number of mesh points depending onMach number. The result indicate, that for the same Mach number, the increasing ofmesh points, lead to increase of the number of iterations

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