Aluminum Cylinder Research Articles

Investigation of the mechanical equivalent of heat using aluminum and brass cylinders

This study explores the mechanical equivalent of heat through controlled experiments using aluminum and brass cylinders. By mechanically rotating these cylinders against a friction band, the conversion of mechanical energy into heat is quantified, demonstrating a fundamental thermodynamic process. The experiment is designed to calculate the specific thermal capacities of the metals and evaluate the efficiency of energy transformation. Results validate the concept that mechanical energy, when converted through friction, becomes thermal energy—affirming the principles outlined in the conservation of energy. This work not only reinforces classical thermodynamics but also enhances our understanding of material properties under thermal stress, offering insights applicable to industrial applications and renewable energy technology. The findings underscore the practical implications of energy transformations in material science and engineering, contributing to the development of more efficient thermal management systems in various technological fields.

A Study on Sensitivity Improvement of the Fiber Optic Acoustic Sensing System Based on Sagnac Interference.

A new pickup structure was introduced and modified to improve the resolution of the linear Sagnac optical fiber acoustic sensing system. The maximum strains corresponding to the material, diameter, wall thickness, and height of the pickups were analyzed by simulation. An aluminum cylinder with a diameter of 110 mm, a wall thickness of 3 mm, and a height of 120 mm was chosen as the basic pickup. A four-groove pickup with a vertical width of 80 mm and a horizontal width of 20 mm was introduced to improve the sensitivity of the system. The experiments showed that the average peak-to-peak sensitivity of the four-groove pickup increased by 215.54% to 106.806 mV/Pa. The improved pickup can be applied in areas to monitor the situation of invasion of the Sagnac optical fiber acoustic sensing system.

Amplification of electromagnetic fields by a rotating body

In 1971, Zel’dovich predicted the amplification of electromagnetic (EM) waves scattered by a rotating metallic cylinder, gaining mechanical rotational energy from the body. This phenomenon was believed to be unobservable with electromagnetic fields due to technological difficulties in meeting the condition of amplification that is, the cylinder must rotate faster than the frequency of the incoming radiation. Here, we measure the amplification of an electromagnetic field, generated by a toroid LC-circuit, scattered by an aluminium cylinder spinning in the toroid gap. We show that when the Zel’dovich condition is met, the resistance induced by the cylinder becomes negative implying amplification of the incoming EM fields. These results reveal the connection between the concept of induction generators and the physics of this fundamental physics effect and open new prospects towards testing the Zel’dovich mechanism in the quantum regime, as well as related quantum friction effects.

Comparison of composite cylinder damage under different working conditions

Abstract The finite element model of the carbon fiber all-wound aluminum cylinder was created to analyze the damage caused by high pressure, and the progression of damage as pressure increased was examined. The damage initially occurs in the transitional area between the cylinder end and cylinder body before progressing to the winding layer of the cylinder. The failure characteristics of the circumferential wound layer contrast with those of the spiral wound layer.

Hydrogen generation based on a gel-like formate system with a palladium catalyst

Catalytic formate decomposition under mild conditions is a promising strategy for hydrogen production as an efficient hydrogen carrier. Most of previous studies performed formate decomposition for hydrogen generation in liquid phase or using formate as a promoter for formic acid decomposition, which exhibits relatively low hydrogen energy density by mass. Here, we reported a gel-like formate system for catalytic hydrogen generation under mild conditions. A H2 yield of 100% with hydrogen energy density by weight of 2.38 wt% was achieved, and the palladium catalyst shows high stability and recyclability for KCOOH gel decomposition. Moreover, the constructed gel-like formate filled in an aluminum cylinder could continuously and steadily supply hydrogen to a 12V/35W fuel cell to drive a LED display. This work may provide a new thought for safe hydrogen storage and production system for hydrogen energy usage in the future.

Growth of β-Ga2O3 crystal with a diameter of 30 mm by laser-diode-heated floating zone (LDFZ) method

To investigate the effect of high-power laser heating on the floating zone (FZ) method, a crystal of β-Ga2O3 was grown by the LDFZ method using a newly developed optical system equipped with a 20-kW laser diode (LD) system as a heat source. The growth started from a twin-free seed crystal with a diameter of 7 mm and the diameter of the crystal was increased gradually up to 30 mm. With increasing the diameter of the crystal, three patterns of the beam intensity profile were switched to heat the whole of the molten zone locally and intensively. The intensity profile of the five beamlets irradiating the sample was adjusted with a combination of the zooming by the optical system and the partial blocking by the alumina cylinder. By the proper tuning of the beam profile and the proper selection of the diameter of the feed rod, the molten zone was kept stable against gravity. The obtained crystal has a layer texture without clear facets or cracks. It almost conserves the crystallographic direction of the seed crystal but is twinned except for a twin-free region near the seed crystal.

An Efficient Low‐Cost Device for Sampling Exhaled Breath Condensate EBC

AbstractWhile exhaled breath condensate EBC is not yet used in routine clinical diagnostics and disease monitoring, recent publications indicate that exhaled air and EBC contain a wide range of molecular biomarkers that are characteristic of various medical conditions. This includes evidently lung disorders such as asthma, COPD, and cystic fibrosis, but also diabetes and several types of cancer go along with specific biomarkers exhaled from the airways. In addition, EBC samples can be collected in a non‐invasive way and, due to their small volume, they can be easily stored frozen between collection and analysis. Several home‐made EBC‐collection systems for research purposes are documented in literature while there are also a few systems from commercial suppliers that are not yet certified as medical products. In this work, a novel collection device is presented in which the EBC is condensed and frozen inside stainless steel tubes, tightly surrounded by an aluminum cylinder that is precooled in a kitchen freezer. The device is low cost, easy to use by patients at home or in a clinic, and its collection efficiency of up to 500 µL min−1 of respiration is on the high side.

Enhanced viscous dissipation of sound in phononic supercrystal

Sound wave propagating in a homogeneous viscous medium decays due viscous losses with decay coefficient γ;0∼ηω2, where η is shear viscosity. Presence of a hard wall strongly increases viscous losses which now occurs mainly within a narrow boundary layer δ. Viscous losses in a 2D phononic crystal are analytically calculated in the low-frequency limit for arbitrary Bravais lattice. The decay coefficient is expressed through series over reciprocal lattice vectors. If the phononic crystal possesses less than 3-fold rotational symmetry it behaves as anisotropic viscous medium. Otherwise, the decay coefficient is isotropic. Depending on the crystal structure and the filling fraction of solid cylinders the decay coefficient γ;ph may exceed γ;0 by two-four orders of magnitude. The decay coefficient may be further enhanced in a supercrystal – a structure with doubly periodicity. The supercrystal is a 2D structure of two sets of aluminum cylinders in air. A periodic set of larger cylinders is imbedded in another set of smaller cylinders arranged in a lattice with smaller period. We present analytical, numerical, and experimental results for decay of sound in a hexagonal supercrystal of aluminum cylinders in air. [This work is supported by the NSF under EFRI Grant No. 1741677.]

Characteristics of Residence Time of the Torrefaction Process on the Results of Pruning Kesambi Trees

The excessive use of Kesambi (Schleichera oleosa) tree stems threatens the sustainability of Kesambi plants since it takes several decades for them to regenerate new stems. This research aims to determine the characteristics of torrefied Kesambi tree pruning. The used reactor has a diameter of 400 mm. An iron basket is positioned 100 mm above the reactor base, holding the material within an aluminum cylinder. The reactor temperature is maintained at 300°C using a K-type thermocouple sensor. A heater is placed near the reactor base and covered. The characteristics of the semi-charcoal biomass product are identified, including mass yield, water absorption capacity, moisture content (D3173, 2013); ash content (ASTM D1102-84. Standard Test Method for Ash in Wood, 2013); volatile matter (%) (ASTMD3175, 2011); and fixed carbon (%) (ASTM, 2013). The color of the leaves and the pruned Kesambi tree changes from brown to black as the residence time increases. The results of pruning the Kesambi tree at different torrefaction residence times indicate a decrease in mass yield with an increase in residence time, with the lowest mass yield observed at a residence time of 20 minutes. The water absorption capacity of torrefied Kesambi tree pruning material is found to be between 0.65% and 0.675%, or less than 1% and higher heating value (HHV) prediction 29.0750 MJ/kg.Keywords: Kesambi, Pruning, Residence, Time, Torrefaction

Particulate Matter Emission and Air Pollution Reduction by Applying Variable Systems in Tribologically Optimized Diesel Engines for Vehicles in Road Traffic

Regardless of the increasingly intensive application of vehicles with electric drives, internal combustion engines are still dominant as power units of mobile systems in various sectors of the economy. In order to reduce the emission of exhaust gases and satisfy legal regulations, as a temporary solution, hybrid drives with optimized internal combustion engines and their associated systems are increasingly being used. Application of the variable compression ratio and diesel fuel injection timing, as well as the tribological optimization of parts, contribute to the reduction in fuel consumption, partly due to the reduction in mechanical losses, which, according to test results, also results in the reduction in emissions. This manuscript presents the results of diesel engine testing on a test bench in laboratory conditions at different operating modes (compression ratio, fuel injection timing, engine speed, and load), which were processed using a zero-dimensional model of the combustion process. The test results should contribute to the optimization of the combustion process from the aspect of minimal particulate matter emission. As a special contribution, the results of tribological tests of materials for strengthening the sliding surface of the aluminum alloy piston and cylinder of the internal combustion engine and air compressors, which were obtained using a tribometer, are presented. In this way, tribological optimization should also contribute to the reduction in particulate matter emissions due to the reduction in fuel consumption, and thus emissions due to the reduction in friction, as well as the recorded reduction in the wear of materials that are in sliding contact. In this way, it contributes to the reduction in harmful gases in the air.

Passive mitigation of low-frequency vibration modes in lightweight structures based on a new generation of acoustic black holes

Topology optimization and generative design are methods used to lighten structures under specific loads. The resulting lightweight components are usually softer in the directions perpendicular to the applied efforts, such as in the case of cranes. This results in the possible excitation of structural modes at very low frequencies, which can lead to premature aging of lightweight structures. In this paper, we present a new design of acoustic black hole (ABH), able to mitigate vibration modes in a test 3D-printed lightweight structure, from 20 Hz upwards. The novel ABH weights less than 10 grams and can be readily screwed on the structure. Its design is based on that of a classic ABH, with additional winglets and/or rods, to increase the vibrating mass without significantly changing the stiffness of the ABH. This results in a strongly reduced ABH cut-on frequency. The winglets and/or rods also result in a greatly increased contact area between the ABH and the viscoelastic dissipative material, with positive effects on the ABH damping efficiency. The new ABHs could successfully be used, first to damp the fundamental vibration mode of aluminum cylinders, and then to reduce the amplitude of the first three structural modes of the test lightweight structure. The new ABH manages to damp modes at frequencies several times lower than the ones found in the literature, which are promising results.

An experimental investigation of the proton fraction in a three electrode 2.45 GHz ECR ion source

The ion beam extracted from a proton ion source contains H+ ion along with H2 + and H3 + molecular ions. In this work, the ionic fractions in the extracted beam of ECR ion source were measured using an analyzing magnet. A computerized proton fraction measurement setup is described in detail with instrumentation and control for pulsed operation of the ECR ion source. A timing diagram has been incorporated for trigger synchronization illustrating the process of pulsing the plasma, controlling the analyzing magnet parameters and acquiring data about the magnetic field and beam current. The proton fraction was measured in two cases, in the first case using SS304 plasma chamber and in the second case incorporating aluminium (Al) cylinder and boron nitride (BN) plates inside the plasma chamber. In the first case, the proton fraction was found to be in the range of ∼60% and in the second case because of the presence of secondary electron donors it increased to 93%. In order to understand the enhancement of H+ fraction in the hydrogen plasma, plasma parameters (ne , Te and EEDF) and its dependence on microwave power and neutral gas pressure were investigated.

The Effect of Single and Multiple Layers of Thin Aluminum Cylinder Walls on High-Speed Impact Behavior

The use of thin-walled structures as impact energy-absorbing media has been carried out by many researchers. The cylindrical tube shape is very popular and is used in an extensive area. Many ways are done to increase the ability to absorb energy and reduce the maximum reaction force. This study investigates the behavior of single- and multiple-layer thin aluminum tubes. The finite element method is used to model specimens and impactors. One end of the sample is subjected to a fixed support, and the other is subjected to impact at a speed of 50 m/s. The specimens used consisted of one, two, three, and four layers with a fixed total thickness of 4 mm. The results showed that the single layer has the slightest total deformation and the most significant reaction force for relatively the same energy absorption. Using more layers increases the deformation length but decreases the reaction force. This is due to the absence of adhesive between layers, so all layers work together simultaneously. The results of this study assist as a recommendation for the manufacture of high-speed impact energy-absorbing structures.

Dynamic instability of reinforced hollow cylinders in a confined underwater environment

An experimental investigation was conducted to understand the collapse mechanisms of internally ring stiffened aluminum cylinders under uniform hydrostatic loading in a confined underwater environment. The implosion of ring stiffened cylinders was studied using a combination of high-speed photography and 3D Digital Image Correlation (DIC). The results show that as stiffener thickness is decreased, the collapse of the structure transitions from two segments collapsing in mode III with the stiffener serving as boundary separating the segments to one uniform mode II collapse where the ring stiffener collapses with the structure. Furthermore, in the cases with two collapses, the behavior of the structure can be described as approaching that of two cylinders divided by a simply-supported boundary condition at the location of the stiffener. The ring thickness also affects the collapse pressure of the cylinder, radial velocity during collapse at the location of the ring stiffener, and dwell time between the collapse of two sections in cases with two collapses.

BUCKLING BEHAVIOR OF RING STIFFENED-ALUMINUM CYLINDERS SUBJECTED TO EXTERNAL PRESSURE

Ring stiffeners are preferably used to enhance thin-walled cylindrical shell buckling resistance while subjected to external lateral pressure. A comprehensive finite element (FE) numerical study investigated the influence of external ring stiffeners varying from 3 to 17 on the buckling strength of thin-walled stiffened aluminum cylinders. Ten ring-stiffened cylinders were modelled using an ANSYS workbench 2021, whose stiffener dimensions were varied such that the overall weight for all ring-stiffened cylinders remained constant. The FE results indicate that specimens with nine and a larger number of stiffeners with lower strength failed in the overall flexural buckling mode (OFBM), and the other with seven and a lesser number of stiffeners with higher strength failed in the local shell buckling mode (LSBM). The optimum number of stiffeners is obtained when both failure modes occur simultaneously. Experimental results and the theoretical solution with reasonable accuracy substantiate the FE results. The experimental, theoretical, and finite element (FE) results indicate that the ring stiffener’s optimum size and spacing can improve the stiffened cylinder buckling strength since critical buckling pressure and failure mode shape were influenced by the ring stiffener’s size and spacing.

Nanosecond laser debonding of strong adhesives

ABSTRACT The goal of this paper is to determine whether laser-induced surface melting can generate adhesive debonding. Commercial cyanoacrylate and acrylic adhesives are used to attach an aluminum (Al) cylinder to a transparent polymethyl(methacrylate) (PMMA) plate, and then a variable force is applied to create an axially loaded butt joint. High energy nanosecond laser pulses at 1064 and 532 nm are directed through the transparent PMMA to be absorbed at the Al surface, causing transient localized heating that leads to joint failure. The dependence of this debonding on both laser fluence (energy per area) and applied force are investigated. Single shot debonding occurs at fluences on the order of 0.47 J/cm2 for 1064 nm and 0.29 J/cm2 for 532 nm pulses with an applied pressure of 0.22 MPa. Characterization of the Al surface before and after laser impact confirms that the debonding arises from surface melting and causes only slight changes to the Al surface. A simple model of the debonding process is developed to explain the dependence of the debonding on the applied load. Single laser pulses can generate instantaneous, relatively clean separation of bonded joints, suggesting that laser debonding may be a promising strategy to initiate deadhesion.

Production of the cylinder head and crankcase of a small internal combustion engine using metal laser powder bed fusion

This effort investigates the use of metal additive manufacturing, specifically laser powder bed fusion (LPBF) for the automotive and defense industries by demonstrating its feasibility to produce working internal combustion (IC) engine components. Through reverse engineering, model modifications, parameter selection, build layout optimization, and support structure design, the production of a titanium crankcase and aluminum cylinder head for a small IC engine was made possible. Computed tomography (CT) scans were subsequently used to quantify whether defects such as cracks, geometric deviations, and porosity were present or critical. Once viability of the parts was established, machining and other post-possessing were completed to create functional parts. Final X-ray CT and micro-CT results showed all critical features fell within ±0.127 mm of the original equipment manufacturer (OEM) parts. This allowed reassembly of the engine without any issues hindering later successful operation. Furthermore, the LPBF parts had significantly reduced porosity percentages, potentially making them more robust than their cast counterparts.

Effect of melt-to-solid volume ratio and preheating temperature on Mg/Al bimetals interface by centrifugal casting

Compound casting is an efficient method for bonding dissimilar metals, in which a dramatic reaction can occur between the melt and solid. The centrifugal casting process, a type of compound casting, was applied to cast Al/Mg dissimilar bimetals. Magnesium melt was poured at 700°C, with melt-to-solid volume ratios (Vm/Vs) of 1.5 and 3, into a preheated hollow aluminum cylinder. The preheating temperatures of the solid part were 320, 400, and 450°C, and the constant rotational speed was 1,600 rpm. The cast parts were kept inside the casting machine until reaching the cooling temperature of 150°C. The result showed that an increase in preheating temperature from 320 to 450°C led to an enhanced reaction layer thickness. In addition, an increase in the Vm/Vs from 1.5 to 3 resulted in raising the interface thickness from 1.2 to 1.8 mm. Moreover, the interface was not continuously formed when a Vm/Vs of 3 was selected. In this case, the force of contraction overcame the resultant acting force on the interface. An interface formed at the volume ratio of 1.5 was examined using scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS), and the results demonstrated the formation of Al3Mg2, Al12Mg17 and (δ+Al12Mg17) eutectic structures in the interface.

Conformal fabrication of functional polymer-derived ceramics thin films

Polymer-derived ceramics (PDCs) is considered to be a promising material for extreme environments such as aero-engine and hypersonic vehicles. However, current methods for PDCs thin films focus on 2D forms, hindering the applications for 3D curved structures where the majority of objects hold complex curvilinear surfaces. To overcome these limitations, a new conformal 3D printing system was developed for in situ preparation of the PDCs films on the curved surfaces for the first time by material extrusion. Through conformal algorithm development and process parameters exploration, different patterns on curved surfaces were realized. Subsequently, a conformal thin film temperature sensor (CTFTS) was fabricated on an alumina cylinder and tested at a high temperature of 800 °C. The results showed that the repeatability of multi-cycles was excellent and the resistance change rate was less than 1 % for half an hour of holding at 400 °C, 600 °C, and 800 °C. Given the high performance of the CTFTS on curved surfaces and the surface compatibility, CTFTS was fabricated conformally on a silicon nitride ceramic bearing and an alumina ceramic bolt, respectively. In the flame test and the rotation test, the CTFTS could detect in situ temperature in real-time with a response better than the commercial thermocouple. Therefore, the PDCs thin film conformal fabrication technique in this study is a highly promising approach for bringing PDCs films to practical applications, as well as a reference for multi-material conformal 3D printing.

Reconversion of Parahydrogen Gas in Surfactant-Coated Glass NMR Tubes.

The application of parahydrogen gas to enhance the magnetic resonance signals of a diversity of chemical species has increased substantially in the last decade. Parahydrogen is prepared by lowering the temperature of hydrogen gas in the presence of a catalyst; this enriches the para spin isomer beyond its normal abundance of 25% at thermal equilibrium. Indeed, parahydrogen fractions that approach unity can be attained at sufficiently low temperatures. Once enriched, the gas will revert to its normal isomeric ratio over the course of hours or days, depending on the surface chemistry of the storage container. Although parahydrogen enjoys long lifetimes when stored in aluminum cylinders, the reconversion rate is significantly faster in glass containers due to the prevalence of paramagnetic impurities that are present within the glass. This accelerated reconversion is especially relevant for nuclear magnetic resonance (NMR) applications due to the use of glass sample tubes. The work presented here investigates how the parahydrogen reconversion rate is affected by surfactant coatings on the inside surface of valved borosilicate glass NMR sample tubes. Raman spectroscopy was used to monitor changes to the ratio of the (J: 0 → 2) vs. (J: 1 → 3) transitions that are indicative of the para and ortho spin isomers, respectively. Nine different silane and siloxane-based surfactants of varying size and branching structures were examined, and most increased the parahydrogen reconversion time by 1.5×-2× compared with equivalent sample tubes that were not treated with surfactant. This includes expanding the pH2 reconversion time from 280 min in a control sample to 625 min when the same tube is coated with (3-Glycidoxypropyl)trimethoxysilane.