Browsing by Author "Aldawi, Fayez"

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Citation Count: Luo, Jie;...et.al. (2022). "Profit and efficiency enhancement of a cylindrical solar collector by structural modification of helical tube", Case Studies in Thermal Engineering, Vol.34.
Profit and efficiency enhancement of a cylindrical solar collector by structural modification of helical tube
(2022) Luo, Jie; Mansir, Ibrahim B.; Sharma, Kamal; Mahariq, Ibrahim; Jarad, Fahd; Youshanlouei, Mohammad Mehdizadeh; Moria, Hazim; Aldawi, Fayez; Reda, Shaker A.; 234808
Cylindrical solar collectors (CSCs) are getting attraction. Heat extraction part of these instruments consists of a helical tube which transfers thermal energy to working fluid. Enhancement of the heat transfer process within this part leads to enhancement of energy achievement. In this paper, influence of applying helical corrugation on helical absorber was evaluated. The number of corrugations and pitch and height of corrugations were considered as variant parameters. The system was evaluated from different viewpoints and performance of system was analyzed based on performance factor and economic viewpoints. The results revealed that the presence of helical Corrugation could increase heat transfer up to 19%. It was found that Dean number of 3000 could be considered as a critical Dean number from view point of performance factor. The application of the proposed system was more beneficial at Dean numbers below 3000. It was revealed that the application of helical corrugation could provide up to 24% enhancement in economic advantage of the system. Best economic performance was related to case with four starts which had corrugation height and corrugation pitch of 0.002 m and 0.103 m and occurred at Dean number of 2000.
Citation Count: Dizaji, Hamed Sadighi...et al. (2022). "Proposing an innovative and explicit economic criterion for all passive heat transfer enhancement techniques of heat exchangers", Energy, Vol. 239.
Proposing an innovative and explicit economic criterion for all passive heat transfer enhancement techniques of heat exchangers
(2022) Dizaji, Hamed Sadighi; Pourhedayat, Samira; Aldawi, Fayez; Moria, Hazim; Anqi, Ali E.; Jarad, Fahd; 234808
Numerous passive heat transfer enhancement techniques (including various types of turbulators) have been proposed before for heat exchangers by many researchers. Their thermal/frictional behaviors have been reported in-detail in term of Nu number, friction factor and so on. However, their economic characteristic has been always immature which is because of lack of an explicit economic criterion (with clear economic unit i.e. dollar per unit of time etc.) applicable for any passive technique through any type of heat exchanger. Hence, this research aims to propose an explicit economic criteria (with a final clear formula) to evaluate the production cost rate of heated/cooled fluid through any type of heat exchanger (with or without passive technique) taking into account all effective parameters (such as capital cost, pumping power, exergy related costs, electricity price of the region, thermal and fluid flow condition through the heat exchanger, ambient condition and so on) and without dependency of other equipment that may work in-line with heat exchanger. The model is developed based on the general standard Specific Exergy Costing theory. The proposed model is a strong economic criterion tool, optimization tool and also comparison tool between different passive heat transfer enhancement methods. Case study as an example application of the model is provided at the last part of the paper.
Citation Count: Ayed, Hamdi...et all. (2021). "Thermal, efficiency and power output evaluation of pyramid, hexagonal and conical forms as solar panel", Case Studies in Thermal Engineering, Vol. 27.
Thermal, efficiency and power output evaluation of pyramid, hexagonal and conical forms as solar panel
(2021) Ayed, Hamdi; Moria, Hazim; Aldawi, Fayez; Farouk, Naeim; Sharma, Kamal; Youshanlouei, Mohammad Mehdizadeh; Mahariq, Ibrahim; Jarad, Fahd; 234808
Through the present investigation, the thermal and power output of novel-shaped solar panels are evaluated. For the cooling of the mentioned forms, forced air flow was utilized. Three novel shapes, of Pyramid, Hexagonal, and Conical which had the equal lateral surface were considered. For the simulation, an open source CFD software was utilized. The lateral surfaces were put under identical amount of heat flux. Air as the coolant fluid was injected with constant inlet temperature from the trapdoors at the bottom of different shaped structures. Three different values of heat flux and air injection rate were evaluated for each shape. The outcomes presented that the conical shaped solar panel exhibits better thermal performance than other geometries. Furthermore, conical form finds the least temperature that was about 10.5 °C less than that of the pyramid-shaped panel. Furthermore, it was revealed that the corners of pyramid and hexagonal-shaped solar panels have higher temperature. Also, it was found that the efficiency of conical shaped panel was up to 8.4% more than that of pyramid-shaped panel.