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Papers by soroush sheykhbaglou

This study investigates the dynamics and properties of non-premixed methane/air flames under thre... more This study investigates the dynamics and properties of non-premixed methane/air flames under three swirl numbers by segmenting flame images using the Otsu thresholding technique. Under three operating conditions, the lean blow out (LBO) and flame length, lift-off height, maximum width, flame angle, and flame pulsing displacements in terms of flame center of gravity, length, and width are measured and compared. A high-speed camera is used to record video of flames, and the image processing of frames collected from a high-speed video was accomplished by using the intermittency distribution method to quantitatively compare flame attributes. The findings show that increasing the swirl number from 0.5 to 0.7 generally has an unfavorable effect on the LBO at given fuel flow rates, and the LBO of flames under 35° (0.6 swirl number) and 40° (0.7 swirl number) swirlers has decreased up to about 15% and 40%, respectively when compared with a 30° swirler (0.5 swirl number). Additionally, observations indicate that the flame length () and liftoff height () drop as the swirl number rises, although the flame width () and angle () show an ascending tendency. Besides, flame lift-off reveals an increasing-decreasing trend with an increment in the airflow, and flame length decreases as the airflow rate increases. It was also observed that flame pulsating displacements in terms of center of gravity (), length (), and width () increases with an increase in the fuel flow rate, and as the swirl number is increased, and lessens, while increases. 2 concentration rises, the flame lift-off height also rises.

Signal, Image and Video Processing, Sep 13, 2022

Engineering research express, Apr 11, 2022

Recent advances in small power-consuming electric devices have increased the demand for appropria... more Recent advances in small power-consuming electric devices have increased the demand for appropriate, compact, rapidly rechargeable, lightweight, and long-lived power sources with higher energy densities. Hydrocarbon fuels are capable of providing high specific energy density, so combustion-based power generators have received increasing attention as an interesting alternative to batteries. In this study, a small power generation system using a miniature-scale swirl burner, two thermoelectric generators (TEGs), a heat medium, and two water blocks as heat sink has been developed. Various swirl strengths ranging from 0 to 1 are studied to find the optimum swirl number (vane angle) for the blow-out limit. The swirl number related to the greatest stable region is found 0.5 which is associated with the 30 ° vane angle for the 3D printed axial swirlers. Because normal-butane is easily liquified and stored, and is in the gas phase at room temperature and atmospheric pressure, it is chosen as the fuel. This paper examines the effect of three thermal input powers of 194 , 291 , and 388 W along with various airflow rates on the performance of the power generation system at the 30 ° vane angle swirler. The results show that about 3 min is needed for our system to reach a steady power output. Moreover, it is observed that the maximum output power is found at the load resistance of R load = 3 Ω for studied operating conditions. Besides, it is shown that by considering the airflow rate fixed, the power output of the system increases with an increase in the fuel flow rate (thermal input power). Furthermore, a maximum power output of 17.2 W is obtained for the fuel flow rate and an airflow rate of 0.200 slpm ( ≈ 388 W ) and 2.7 slpm , respectively, which corresponds to a conversion efficiency of about 4.5 % at R = 3 Ω load resistance.

International Journal of Chemical Engineering

Combustion and flame characteristics of laminar methane/air and n-butane/air flames in a 3D-print... more Combustion and flame characteristics of laminar methane/air and n-butane/air flames in a 3D-printed micro-slot burner is compared and reported in this study. The stability limit, flame appearance, and emission performance are investigated experimentally. In addition, past research on conventional burners is compared with the results of this study throughout the paper. The construction of this micro-slot burner was met by selective laser melting (SLM) process. Flame characteristics such as lift-off height, length, visible area, maximum width, and neck width are obtained using an image processing algorithm and are examined at different fuel and airflow rates. The results show that the blow-out limits of methane/air and n-butane/air flames are almost the same when compared at the same volume flow rates, although the methane/air flames are more stable than n-butane/air flames at the same thermal input powers. A region of interesting rope-like oscillatory flames (that has never been seen...

Modares Mechanical Engineering, Nov 10, 2020

In this paper, the experimental study of partially premixed combustion of pure methane/ oxygen ha... more In this paper, the experimental study of partially premixed combustion of pure methane/ oxygen has been implemented in a 5 mm diameter meso-scale quartz reactor that has 1 mm wall thickness and 5, 10, and 15 cm lengths. Mixing ratios of 25 % , 50 % and 75 % have been used for partially premixed combustion tests. Experimental results including the factors affecting flame regimes, formation range, flame dynamics, and the outer wall temperature distribution of the reactor have been analyzed. The tests were performed in an axisymmetrically centered cylinder combustion chamber (uniform co-axial flow) and laminar flow regimes. In most partially premixed combustion experiments, the Repetitive Extinction and Re-Ignition (RERI) flame, which had an optimal heat distribution throughout the reactor, have been observed. The flame dynamics were mostly affected by changes in mixing ratio, reactor length, oxygen flow rate, and finally fuel flow rate (equivalence ratio) respectively. Also, observations revealed that by increasing the reactor length due to the appropriate time for homogenization of the mixture, differences in the flame formation interval were reduced in different ratios of the reactant pre-mixes.

Signal, Image and Video Processing

Article Type Original Research In this paper, the experimental study of partially premixed combus... more Article Type Original Research In this paper, the experimental study of partially premixed combustion of pure methane/ oxygen has been implemented in a 5 mm diameter meso-scale quartz reactor that has 1 mm wall thickness and 5, 10, and 15 cm lengths. Mixing ratios of 25 %, 50 % and 75 % have been used for partially premixed combustion tests. Experimental results including the factors affecting flame regimes, formation range, flame dynamics, and the outer wall temperature distribution of the reactor have been analyzed. The tests were performed in an axisymmetrically centered cylinder combustion chamber (uniform co-axial flow) and laminar flow regimes. In most partially premixed combustion experiments, the Repetitive Extinction and Re-Ignition (RERI) flame, which had an optimal heat distribution throughout the reactor, have been observed. The flame dynamics were mostly affected by changes in mixing ratio, reactor length, oxygen flow rate, and finally fuel flow rate (equivalence ratio)...

Future Energy, Feb 15, 2023