Spherically expanding flame propagations have been employed to measure speeds for H2/CH4/air mixtures over a wide range of H2 fractions (30 %, 50 70 and 100 % hydrogen by volume), at initial temperatures 303 K 360 K, pressures 0.1, 0.5 1.0 MPa. The equivalence ratio (ϕ) was varied from 2.5 pure 0.8 1.2 methane/hydrogen mixtures. Experimental laminar burning velocities Markstein numbers methane/hydrogen/air high pressures, which are crucial gas turbine applications, very rare in the...

The extraction of cellular structure feature on the spherical premixed flame surface faces accuracy challenges. Schlieren technique was employed to obtain hydrogen-air flames images in a constant volume vessel at room temperature and atmospheric pressure under an equivalent ratio 0.8 this work. A bio-inspired Cellpose 2.0, driven by deep learning, is innovatively introduced train cell segmentation model combustion field. After labeling training cells different shapes sizes, efficient...

In this study, the influences of pressure, temperature and equivalence ratio on onset cellular instabilities in premixed hydrogen/air laminar flames were studied using a constant volume fan-stirred combustion vessel. The instability is marked by critical stretch rate, at which flame speed rapidly deviates from its prior response to stretch. It noted that Peclet number, Pecl, increases with increasing both temperature, indicating more stable flame. Whilst, Pecl decreases initial pressure due...

Darrieus–Landau (D-L) instability can cause significant acceleration in freely expanding spherical flames, which lead to accidental large-scale gas explosions. To evaluate the potential of using high-pressure lab-scale experiments predict onset cellular instabilities atmospheric explosions, experimental measurements for hydrogen and methane mixtures are conducted, laboratory explosions at elevated pressures. These compared with those from several experiments. Comprehensive correlations...

Laminar flame characteristics of ethane/hydrogen/air (with XH2 = 25 %, 50 75 % and 100 by volume) within an equivalence ratio from 0.7 to 1.3 were determined in a spherical constant volume combustion vessel at elevated pressure up 0.5 MPa, temperature 360 K. Key such laminar burning velocity, Markstein length/number, thickness, effective Lewis number, thermal expansion coefficient critical conditions the onset cellular instability including radius Peclet either measured or calculated. These...

This paper presents an implemented analysis of improved rectangular 1x4 microstrip patch antenna array parameters utilizing parasite-like element directors. The proposed design methodology based on Yagi theory. Three identical directors was loaded the to improve such as maximum radiated power intensity (UMax), directivity (D), gain (G), (Prad) and radiation efficiency (e0) while maintaining return loss (RL) bandwidth (BW) at 2.4 GHz. calculations outcomes show how employing can enhance...

2-Amino-4-phenyl-5,6,7,8-tetrahydroquinoline-3-carbonitrile (3) was synthesized by treating cyclohexanone (1) with 2-benzylidenemalononitrile (2) in the presence of ammonium acetate. The reactivity compound 3 towards dimethylformamide dimethyl acetal (DMF-DMA), carbon disulfide, urea, thiourea, formamide, formic acid, acetyl chloride and isothiocyanate were studied. In addition, antimicrobial activity some selected derivatives is reported.

Particle Image Velocimetry, PIV, is employed to characterise the near-homogeneous, isotropic, turbulence generated inside a large spherical vessel by four rotating fans. Spatial and temporal distributions of mean root square, rms, velocity fluctuations are investigated, as well integral length scales, L, Taylor microscales, λ, Kolmogorov η, in fan speed range, 1000–6000 rpm. Mean velocities about 10% velocity, u′ close homogeneous isotropic central volume. This volume decreases with...

The self-acceleration and global pulsation of spherically expanding laminar hydrogen-air flames were studied in a spherical explosion vessel, over wide range equivalence ratios (0.4–2.0), initial temperatures (300–400 K), pressures (0.1–0.7 MPa). Comprehensive quantitative data on the propagation unstable obtained. results show that self-similarity appears after onset instability, previous assertion acceleration exponent α = 1.5 is not valid for flames. derived values such vary from 1.125...

Coal-based naphtha is a promising alternative fuel as it fits the standards of energy replacement and technologically mature, safe, dependable. However, its laminar combustion characteristics have not been well studied. The burning velocities Markstein lengths kind coal-based (C6.97142H15.88244) over range initial conditions were measured by Particle Imaging Velocimetry (PIV) in spherical explosions. In addition, 3-component surrogate model (62.4 mol% n-C6H14, 32.5 i-C8H18 5.1 i-C7H16) based...

The cellular flame area continues to increase with the development of cells on spherical surface, which will greatly promote burning rate and propagation speed. This work mainly focuses a new three-dimensional (3D) reconstruction method structure attempting quantitatively characterize real area. Initially, visualization investigation hydrogen-air premixed flames within constant volume vessel was conducted using Schlieren optical technique under room temperature atmospheric pressure...

Particle image velocimetry (PIV) has become a popular non-intrusive tool for measuring various types of flows. However, when three-dimensional flows with two-dimensional (2D) PIV, there are some uncertainties in the measured velocity field due to out-of-plane motion, which might alter turbulence statistics and distort overall flow characteristics. In present study, three different models employed compared. Mean fluctuating fields obtained by computational fluid dynamics modeling compared...

The overall equipment effectiveness (OEE) tool is a plan for increasing the efficiency of manufacturing processes and equipment, including loading time, preparing tasks, machines usage. Many companies seek to improve their products raise achieve high quality OEE solution find out reason delaying product, it calculates inefficiencies classifies them into three categories better understanding method. case study investigates cable rack stages at Masar Company Metal Industries, Alexandria ARE...

Automatic modulation classification (AMC) recreates an essential part in both cooperative and noncooperative communication applications. AMC is employed to automatically determine the types of transmitted signals. This done by noting recived information instances, which would be manipulated noise as well fading channels. It a middle process between signal detection data retrieving. In this paper, novel feature-based ACM proposed its performance investigated. The based on support vector...

This paper proposes a new compressive sensing (CS)-dependent direction of arrival (DOA) estimation technique based on beam-space (BS) processing. Two techniques have been proposed, namely, full (FBS) as well multiple (MBS), and investigated versus the ordinary element-space (ES) in CS-based framework. Both proposed plans will identify more source signals than number sensors used, without requiring priori knowledge signs to be evaluated. The exhibition methods is contrasted with that ES-based...

Microstrip antennas are vital components in the military X-Band (6.2:10.9) GHz systems to achieve high performance for these systems. In this paper hybrid shapes of slots introduced as, International Telecommunication Conference 2021 Air Defense College (ITC-2021 ADC) shape a reference patch antenna (RPA) using HFSS simulator inter telecommunication system applications. The proposed structures introduce RPA without <tex xmlns:mml="http://www.w3.org/1998/Math/MathML"...