Tikrit Journal of Engineering Sciences

In the present paper, Numerical simulation is performed to investigate the laminar force convection of Al2O3/water Nanofluid in a flow channel with different constant heat flux 50, 90, 150 W/cm2 respectively and two values of mass flow rate of fluid. The heat sources are placed on the bottom wall of channel which produces much thermal energy that must be discarded from the system. The remaining surfaces of channel are kept adiabatic to exchange energy between Nanofluid and heat sources. The effects of Reynolds number Re < 1000), the volume fraction of nanoparticles of nanofluid have the percentages of 0, 1, 3 and 5%. on the average heat transfer coefficient (h), pressure drop (∇P), surface Nusselt number and wall temperature ( Tw ) are evaluated. The use of Nanofluid can produce an asymmetric velocity along the height of the channel. The results show that the wall temperature decreases remarkably as Re and volume of fraction increase. It is also observed that there is an enhancement of average heat transfer coefficient and it’s observed also that the use of Nanofluid improves MCHS performance by reducing fin (conductive) thermal resistance.

A correlation of measured data for the solar radiation on a horizontal surface at ambient temperature and humidity was achieved. For all measurements being hourly averaged to fifth order polynomial. The data correlated to a second degree equation with time for an hourly, daily and monthly obtained data. This correlated data compared to best predictive models for the same site of observation. However these measurements appeared to be sensitive to minor and major changes of local weather patterns which is reflected in a deviation to about 4% to the lower margin and 5% to its higher margin.

This paper introduces a technique to design an bits bidirectional port to be connected with soft core microblaze processor system that is configurable on Spartan 3E slice. A soft core processor system with peripheral is designed using embedded design technique with integrated software environment (ISE tool) supplied by Xilinx. An interrupt system controller is added to the designed system to control the incoming interrupt signal to promote the interrupt service routine to deal with incoming data. The system performance is tested by sending and transmitting packets of data from and to a MatLab program using the P.C parallel port.

Traditional 3D-Bresenham’s algorithm is efficient in generating lines on raster systems using only integer calculations. This algorithm is needed as a solution of hidden surface problem using depth-buffer method to calculate z value for each pixel, while calculated values of x and y are used to address frame buffer memory, z value is used to test hidden surface by saving the closest depth in depth buffer. In this paper Bresenham’s algorithm for plotting 3D-lines is examined then modified to simplify hardware requirements during implementation phase. Basing on efficiency of the algorithm on the space symmetry an enhanced version of this algorithm is implemented using OpenGL. Experimental results confirm results calculated theoretically for both traditional and modified algorithms. The hardware implementation is accomplished for real time applications, and a graphic sub-system is designed using FPGA. Finally, a comparison is accomplished for Spartan3E utilization which is used to implement the hardware unit.

Flexural strength and deformation of reinforced concrete beams strengthened with steel plates were studied in this paper. For bonding the steel plate to the beam a technique of welding steel plate to the stirrups was followed. Fifteen beams were cast and tested; nine beams were strengthened by steel plates preloaded with a fraction of the ultimate load of the control beams (three beams) and then tested to failure. Another three beams were cast and tested to failure also, strengthened and then retested to failure. The test results indicated that the process of welding is successful and can furnish the state of composite action. After strengthening, the ultimate load was increased by 1 to 17 % and by 70 to 94 % for beams strengthened with 1 mm thick and 3 mm thick steel plates, respectively. The effect of cracking due to preloading on the flexural behavior of strengthened beams was found to be not significant.

This paper reports an experimental study for the effect of forced vertical vibrations on natural convection heat transfer, by the use of longitudinally finned plate made from Aluminum with dimensions (100, 300 and 3 mm). The sample of test was heated under the condition of a constant heat flux which is generated by applying an alternating voltage on a fixed resistor mounted on the underside of the sample test which was located horizontally or inclined in multiple angles at a range of (30°,60oand 90°). An experimental set-up was constructed and calibrated, 16 sets of fin-arrays were tested in atmosphere. Fin length, fin thicknesses and fin height were fixed at 300 mm, 3 mm and 13 mm respectively. The base-to-ambient temperature difference was also varied independently and systematically with the power supply to the heater ranging from 250 W/m2 to 1500W/m2. The frequency was varied at (0, 2, 6, 10 and 16 Hz) and the amplitude wain the range of (1.63-7.16 mm).The relation between the heat transfer coefficient and the amplitude of vibration is directly proportional with the inclination angle from (0o, 30o, 60o).Results show that the heat transfer coefficients of the heated plate in (30o) angle are about (19.27%) greater than those for the (60o) and exceeds that of the (90o) by (31.4%).

The mathematical modeling of continuous stirred tank reactor system is developed based on the mass and energy balances for the reactor and heating system. The system is studied by introducing step change in concentration, inlet flow, flow of heating fluid, inlet temperature and heating fluid temperature and measuring the temperature change in the reactor. In this paper, a fuzzy logic controller has been designed and evaluated. Through simulation study by using MATLAB, it has been shown that the proposed fuzzy logic controller has given an excellent tracking and regulation performance compared to that of the PID control system.

In steam power plants, and high pressure high temperature water flow, phase change takes place resulting in bubbly flow. Such flow causes vibration and noise in the conduits. The present study emphasized on cavitations during a dual phase flow (water- vapor) with a variation of velocities at different conditions in converge-divergence nozzle. The investigation was carried out experimentally and numerically, by CFD simulation. A transparent material is used of PMMA in order to visualize the various regions of the flow. Furthermore, the effect of flow velocities on vibration and noise was evolved in the experimental measurements. The CFD simulation model of this problem is defining a dual compressible viscous flow with k-epsilon model for the turbulence modeling. The analyses of the simulation results and the experimental observation have been seen to be comparatively conscionable in the cavitation zone and the estimation of the throat pressure cavitations during a dual phase flow with a variation of mass transfer conditions. A model were combined with a linear viscous turbulent model for the mixed fluids in the computational fluid dynamics software. A CFD Code with modified user intervention is used to simulate steady cavitation. Some of the models were also tested using a three dimensional -CFD code in configurations of cavitation on three-dimensional a converge-diverge sections. The pressure distributions and volume fractions of vapor at different cavitation numbers were simulated, which agreed well with experimental data.

This research includes practical results of study the behavior of the reinforced concrete beams strengthening by carbon fiber strips using near surface mounting (NSM) technique. The study is carried out on (8) concrete beams, the variables which considered are (the length of CFRP strips, no. of CFRP layers), this established by dividing the practical program into two groups, the first one includes (3) beams strengthened with variable carbon fiber strips length and one strip, Second group of this study includes (3) beams which strengthened with variable carbon fiber strips length and two strips, as well as two control beams . The results indicated that the carbon fibers had a noticeable effect in increasing the bearing capacity of the near surface mounting (NSM) strengthened technique reinforced beams, , the results indicated that strengthening the beams with carbon fibers and not along the length of the beam and in one layer did not contribute to increasing the beams strength, but when the number of layers was increased for the same length of fibers an increase in beam strength was noticed at a rate range (34%-55%).

It’s possible to use the recently technique and programs to assist in process geotechnical analysis such as prediction of geotechnical properties in the left side of Mosul city about (131) km2 , as water content , gypsum content , water table elevation…. etc , that is significant effect of the soil , from more than 300 boreholes in the study area , with depth (1-35) m. Based on the data collecting from several resources this research performs advance spatial statistical analysis that is available in the GIS programs. It is getting on mathematical and statistical relationship that is using in the prediction works.

Baker’s yeast is an important additive to improve bread quality. Baker yeast produced in two methods (batch or continues fermenter). In this investigation the continuous operating conditions in reactors were studied to predict the best conditions of product. Experimental runs were implemented in a 12-liter pilot-scale fermenter. The simulation carried out between the experimental and the theoretical results and gives a good results presentation of growth rote, the rate of substrate additives, pH and rate of ethanol production. The process is modeled and par formed using a computer programming prepares for this purpose.

The research study has performed to investigate the ferrocement beam element which is subjected to rise of temperature under different flexural loads. The experimental program includes a ferrocement beams fabricated of cement mortar contained varying number of layers (or variable volume fraction ratio) of steel welded wire mesh of square openings (4, 6, and 8 layers). Four groups of beams were studied ; all beams have the same dimensions, and exposed to three temperature rates namely ( 333°C, 453 °C and 600°C) and compared to the control ferrocement beams (reference group) without exposing to temperature rate. The main three parameters of the ferrocement beams (mix ratio, number of steel wire mesh layers and rising of temperature degree) as a structural performance parameters used for comparing ultimate flexure failure load and load- deflection relations . Throughout this study, the properties of ferrocement elements subjected to heating conditions are very important for structural stability, structural behavior and durability.