Papers by Ayad T . Mustafa
WIT Transactions on Ecology and the Environment, 2016
The behaviour of artificially generated vortex by solar utilization is not well understood, as it... more The behaviour of artificially generated vortex by solar utilization is not well understood, as it is compressible, turbulent and 3-D. The present paper is aimed to simulate and analyse a new solar updraft power system, named vortex generation engine (VGE) to provide basic understanding of the artificial vortex. The main focus is on the effect of the upper plate diameter on the vortex structure. The simulation was carried out by CFD using ANSYS FLUENT 15. The modelled engine has 1.0 m outer diameter, 0.6 m height and 8 slots on the circumferential of the VGE for the air flow from the solar collector zone to the engine zone. The numerical procedure was validation by comparing the predicted temperature results with experimental measurements. The results have demonstrated that the upper hole of the VGE has considerable effect on the vortex generation. When the diameter of the upper hole increased from 0.3 m to 0.9 m, the strength of the generated vortex decreased. The visualization through CFD simulation illustrates that a flow circulation exists at many regions in the engine body, which reduce the system performance. As the technique is new, there is a lot of room for further investigation and improvement of the design parameters of the proposed engine.
International Journal of Sustainable Development and Planning, 2015
Thermal energy transfer in the atmosphere occurs from a high temperature zone to a low one by mea... more Thermal energy transfer in the atmosphere occurs from a high temperature zone to a low one by means of convective vortices where mechanical energy is produced. There are two ways of driving vertical flow in the core of a vortex: (1) by the direct action of buoyancy acting on hot air and (2) by producing a vertical pressure gradient along the axis of a vortex because of core development involving the lateral spread of the vortex with height. In particular, it indicates that the intensity of convective vortices depends on the depth of the convective layer via thermodynamic efficiency, the enthalpy perturbation across them, and the existence of sources of vorticity. The atmospheric vortex engine (AVE) is a device for producing an artificial vortex. The operation of AVE is based on the fact that the atmosphere is heated from the bottom and cooled at the top. By artificial vortex generation, it is aimed to eliminate the physical solar updraft tower and reduce the capital cost of solar chimney power plants. This paper reviews natural convective vortices and vortex creation via physical principles of vortex generation. Vortex analysis and modelling are presented. Furthermore, a new model of a solar vortex engine (SVE) is proposed and discussed. An idea on utilizing the solar energy as the heat source for establishing the vortex and operating the SVE model is adopted. The SVE model is feasible and promising for electrical power generation.
Journal of Engineering, 2018
Solar collectors, in general, are utilized to convert the solar energy into heat energy, where it... more Solar collectors, in general, are utilized to convert the solar energy into heat energy, where it is employed to generate electricity. The non-concentrating solar collector with a circular shape was adopted in the present study. Ambient air is heated under a translucent roof where buoyant air is drawn from outside periphery towards the collector center (tower base). The present study is aimed to predict and visualize the thermal-hydrodynamic behavior for airflow under inclined roof of the solar air collector, SAC. Three-dimensional of the SAC model using the re-normalization group, RNG, k−ε turbulence viscus model is simulated. The simulation was carried out by using ANSYS-FLUENT 14.5. The simulation results demonstrated that at same insolation; airflow, ground and air temperatures increase when the collector radius decreases towards the collector center. The ground temperature and air velocity increase, while airflow temperature decreases when the inclination angle increases from 0...
Convective vortices are common features of atmosphere that absorb lowerentropy-energy at higher t... more Convective vortices are common features of atmosphere that absorb lowerentropy-energy at higher temperatures than they reject higher-entropy-energy to space. Via the thermodynamic efficiency, it has been predicted that the intensity of convective vortices depends on the depth of the convective layer. The atmospheric vortex engine is proposed as a device for producing mechanical energy by means of artificially generated vortex. The operation of the engine is based on the facts that the atmosphere is heated from the bottom and cooled from the top. By generation of the artificial vortex, it is aimed to eliminate the physical solar updraft tower and reduce the capital of the solar chimney power plants. The paper presents the fundamentals of the atmospheric vortex engine, and reviews the state of the art in topic. Furthermore, the paper discusses an idea on utilizing the solar energy as heat source to operate the system. In conclusion, the system is feasible and promising for electrical power generation.
The Journal of Engineering, 2011
The objective of this research is to study experimentally the effect of air flow rate on humidifi... more The objective of this research is to study experimentally the effect of air flow rate on humidification process parameters. Experimental data are obtained from air conditioning study unit T110D. Results obtained from experimental test, calculations and psychometrics software are discussed. The effect of air flow rate on steam humidification process parameters as a part of air-conditioning processes can be explain in results obtained. Results of the steam humidification process with and without preheating with 5A and 7.5A shows decreasing in dry bulb temperature, humidity ratio, and heat add to moist air with increasing air flow rate, but humidification load, and total energy of moist air increase with increasing air flow rate in the testing tunnel. The steam humidification process with dehumidifying coil shows increase in dry bulb temperature, humidity ratio, humidification load, and heat add to moist air with increasing air flow rate in the testing tunnel, but the total energy decr...
An experimental study for heat transfer process by mixed convection in the entrance region of ann... more An experimental study for heat transfer process by mixed convection in the entrance region of annulus with uniformly heated stationary outer cylinder and rotating inner shaft has been carried out. The present study aimed to investigate the local and average heat transfer along the axial distance of outer cylinder in horizontal and vertical positions. The experimental setup consists of an annulus with a radius ratio of 0.37 and outer cylinder with a heated length of 1.12m. The experimental investigation was achieved within Reynolds number ranges from 1000 to 2400 and Taylor number values of 0, 158933, 225269, and 506856. Moreover, the Richardson number ranges between 1.09 (mixed convection) to 0.104 (forced convection) in vertical position, and between 1.05 (mixed convection) to 0.113 (forced convection) in horizontal position. The results showed that the local Nusselt number values increase when the heat flux, Reynolds number and Taylor number increase. It is found that the values o...
So as to promote the power plant performance, some developments and progressive configurations we... more So as to promote the power plant performance, some developments and progressive configurations were suggested for the components of the solar updraft tower power plants. A detailed literature survey of development of performance enhancement techniques were presented and discussed in the present paper. The survey gives a summarize overview of the developments in each of the components key area inspect to raise the performance of the currently solar
Journal of Advanced Research in Fluid Mechanics and Thermal Sciences
Solar energy reaching Earth can be used as promising renewable energy to overcome the challenges ... more Solar energy reaching Earth can be used as promising renewable energy to overcome the challenges of steam generation processes. Solar concentrators suffer from fine adjustment of solar radiation concentration and high investment cost. Therefore, multi-configuration receivers named the cylindrical cavity receiver, helical receiver, and the absorber-evaporator-tank have been manufactured from the coiled copper tube and brass plates, respectively. Then, they are tested and compared to improve the performance of steam generators. The performance of the absorber-evaporator-tank receiver has been compared with the cylindrical cavity receiver and helical receiver for a period from 10 am to 12 pm. The present investigation shows that the boiling point of water increasing when the pressure of generated steam increases particularly inside the coiled tube, which affects the dryness fraction of the generated steam. The present results show that the efficiency of the absorber-evaporator-tank is ...
The behaviour of artificially generated vortex by solar utilization is not well understood, as it... more The behaviour of artificially generated vortex by solar utilization is not well understood, as it is compressible, turbulent and 3-D. The present paper is aimed to simulate and analyse a new solar updraft power system, named vortex generation engine (VGE) to provide basic understanding of the artificial vortex. The main focus is on the effect of the upper plate diameter on the vortex structure. The simulation was carried out by CFD using ANSYS FLUENT 15. The modelled engine has 1.0 m outer diameter, 0.6 m height and 8 slots on the circumferential of the VGE for the air flow from the solar collector zone to the engine zone. The numerical procedure was validation by comparing the predicted temperature results with experimental measurements. The results have demonstrated that the upper hole of the VGE has considerable effect on the vortex generation. When the diameter of the upper hole increased from 0.3 m to 0.9 m, the strength of the generated vortex decreased. The visualization thro...
In this study, mathematical and experimental models were implemented for circular solar air colle... more In this study, mathematical and experimental models were implemented for circular solar air collector. Modeling methodology with conservation equations of continuity, momentum and energy were presented, and model solution is obtained by utilizing a developed code in MATLAB program. An experimental model of concentric circles with outer and inner diameters of 8.8 m and 1.0, respectively, was designed and fabricated in order to perform measurements for the thermal and flow processes in the system. The canopy was inclined by 8.5 o . The results showed that, at same solar irradiation, the temperatures of air flow, canopy and ground are increasing by decreasing the radius. When the canopy slope increases, air flow temperature decreases and canopy temperature increases for a constant solar radiation. When the solar radiation increases, air flow, canopy and ground temperatures increases for the same collector radius. The validations of the model predictive and therefore comparisons with re...
Journal of Mechanical Engineering and Sciences
The thermal behavior of hot air in a natural convection mode on a solar absorber-plate has not be... more The thermal behavior of hot air in a natural convection mode on a solar absorber-plate has not been, so far, modeled experimentally. The present work aimed to assess the performance of the inclined solar air heater [SAH] experimentally by investigating the temperature distribution field in the natural convection flow. The solar plate collector is designed based on the aspect ratio of length to height, L / H, of 6 and 12. The measurements are carried out for the collector tilt angles of 30°, 45°, 60° and 75°. The present investigation demonstrates the temperature distribution of hot air floated in an inclined channel of the SAH. The investigation showed 2D thermal stratification increases when increasing the distance along the collector plate, which looks clear in the SAH with a height of 10 cm. The results of the study show that the thickness of the thermal layers increases with increasing the tilt angle from 30˚ to 75˚. The reason dates back to increasing the buoyancy force of the ...
2ND INTERNATIONAL CONFERENCE ON MATERIALS ENGINEERING & SCIENCE (IConMEAS 2019)
Thermal stratified storage tanks are an effective method to improve the efficiency of thermal sto... more Thermal stratified storage tanks are an effective method to improve the efficiency of thermal storage devices that are commonly used in thermal systems when the available energy source is irregular or when a time lag exists between the production and the demand. It has been shown that thermal stratification is affected by a number of factors such as mixing due to the inlet and outlet streams, heat losses to the environment and tank configuration such as the aspect (height to diameter) ratio. Thermal behavior and stratification of hot water storage tanks during the stagnation mode is investigated experimentally in this study for three different aspect ratios (AR) of the tank, namely 2, 1 and ½. The study addresses the change in water stratification during the cool down of the water inside the storage tank of thermal systems in the 85 o C to 30 o C temperature range, which lies within the operating range of most conventional and solar hot water and liquid based heating systems.
Uploads
Papers by Ayad T . Mustafa