Aerospace Engineering eJournal最新文献

{"title":"Investigation on the Air-Gas Characteristics of Air-Hydrogen Mixer Designed for Dual Fuel – Engines","authors":"Alaulddin A. Kazum, Osam H. Attia, Ali I. Mosa, Nor Mariah. Adam","doi":"10.21303/2461-4262.2021.001722","DOIUrl":"https://doi.org/10.21303/2461-4262.2021.001722","url":null,"abstract":"High smoke emissions, nitrogen oxide and particulate matter typically produced by diesel engines. Diminishing the exhausted emissions without doing any significant changes in their mechanical configuration is a challenging subject. Thus, adding hydrogen to the traditional fuel would be the best practical choice to ameliorate diesel engines performance and reduce emissions. The air hydrogen mixer is an essential part of converting the diesel engine to work under dual fuel mode (hydrogen-diesel) without any engine modification. In this study, the Air-hydrogen mixer is developed to get a homogenous mixture for hydrogen with air and a stoichiometric air-fuel ratio according to the speed of the engine. The mixer depends on the balance between the force exerted on the head surface of the valve and the opposite forces (the spring and friction forces) and its relation to decrease and increase the fuel inlet. Computational fluid dynamics (CFD) analysis software was utilised to study the hydrogen and airflow behaviour inside the mixer, established by 3.2 L engine. The Air-hydrogen mixer is examined with different speeds of engine1000, 2000, 3000 and 4000 RPM. Results showed air-hydrogen mixture was homogenous in the mixer. Furthermore, the stoichiometric air-fuel ratio was achieved according to the speed of the engine, the developed mixer of the AIR-Hydrogen mixing process provides high mixing homogeneity and engines with stoichiometric air-fuel ratios, which subsequently contributes to the high levels of efficiency in engine operation. In summary, the current study intends to reduce the emissions of gases and offer a wide range of new alternative fuels usage. While the performance of the diesel engine with the new air-hydrogen mixer needs to be tested practically","PeriodicalId":360260,"journal":{"name":"Aerospace Engineering eJournal","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133792665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of Position and Rotation Direction of Double Stirrer on Chaotic Advection Behavior","authors":"Sugeng Hadi Susilo, Asrori Asrori","doi":"10.21303/2461-4262.2021.001707","DOIUrl":"https://doi.org/10.21303/2461-4262.2021.001707","url":null,"abstract":"Turbulent mixing can damage the material molecules because of turbulence. Whereas laminar mixing raises a problem when mixing is carried out on viscous liquids. The mixing mechanism using chaotic flow affects the mixing quality. The aim of the experiment was to determine the position and direction of the double stirrer chaotic mixer. The installation of a chaotic mixer uses a cylindrical tub and two different mixers consisting of a primary mixer (Pp) and a secondary mixer (Ps). Periodically rotate the container and stirrer. The center of the vessel and primary mixer are placed at the same coordinates. For ε=4 cm (Pp to Ps distance), there are three experiments, namely: vessel rotation and directional stirrer (P2S-a), vessel rotation and opposite stirrer (P2B-a), and vessel rotation, both primary and secondary stirrers are directional variations. (P2V-a). Eccentricity 7 cm, there are also three treatments as above: one direction (P2S-b), reverse direction (P2B-b), and variation of direction (P2V-b).<br><br>The video camera recordings are processed digitally. Qualitative data show a pattern of behavior during mixing. Meanwhile, quantitative data is used to determine the level of mixing effectiveness. The results showed that the direction of rotation of the two cylinders had no effect on the effectiveness of chaotic mixing. Based on the number of initial droplets of dye, the treatment that experienced the fastest chaos was P2B-b, at n=2 and r=3.5303. The difference in the number of color droplets does not affect chaotic behavior. The highest mixing efficiency was generated by the lowest P2V-b mixing index value of 0.94. Simultaneously, the direction between the mixer and the container will provide maximum mixing efficiency. Isolated mixing areas (island) and areas of poor mixing occur because of one-way rotation and low eccentricity","PeriodicalId":360260,"journal":{"name":"Aerospace Engineering eJournal","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126383120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Management of Buffer Systems in Automotive Stabilized Production Networks – A Qualitative Analysis","authors":"Mareike Mueller","doi":"10.2139/ssrn.3701532","DOIUrl":"https://doi.org/10.2139/ssrn.3701532","url":null,"abstract":"Automotive manufacturers are operating in global and cross-linked production networks. From a productions and logistics point of view they act as consignors and consignees of material, components and car bodies within these networks. The demand for customized cars, rapidly changing market environments, local market regulations and technology leaps force companies to orient their operational activities towards more flexible and resilient production strategies. One promising method to deal with the evolving complexity, uncertainty and volatility is to establish a stabilized production system. This concept requires several prerequisites, above all a high degree of stability in the production process. Buffers are allocated to perform multiple functions in order to provide stability. Opposing objectives of stakeholders, unfavorable infrastructural settings and the lack of an integral planning process can be an obstruction towards effective buffer allocation in production networks. If not applied in an integrated approach considering all functions buffer capacity can lead to an adverse effect on the overall performance. Misaligned buffers lower the efficiency, reduce the flexibility and increase the complexity of production systems. This article presents trade-off observations and challenges system designers are confronted with during the allocation of buffers in stabilized production networks. The most significant trade-off is between the two competing objectives of stability and throughput. Best practice on how to implement buffers and manage the arising trade-off are presented.","PeriodicalId":360260,"journal":{"name":"Aerospace Engineering eJournal","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115427968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Angular Momentum Tearing Mechanism Investigation Through Intermolecular at the Bubble Interface","authors":"T. Tjahjono, I. Wardana, M. N. Sasongko, A. Widodo","doi":"10.15587/1729-4061.2020.208333","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.208333","url":null,"abstract":"Two-phase flow with gas-liquid component is commonly applied in industries, specifically in the refinery process of liquid products. Oil products with bubbles contents are undesirable in a production process. This paper describes an investigation of a process mechanism regarding the bubble breakup of the two-phase injection into quiescent water. The analytical model was developed based on the force mechanism of water flow at the bubble interface. The inertia force of water flow continually pushes the bubble while the drag force resists it. The bubble gets shapes change that affects the hydrodynamic flow around the bubble. Vortices with high energy density impact and make the stress interface over its strength so that the interface gets tear. The experiment was carried out by observing in the middle part of the injected flow. It was found that the forming process of bubble breakup can be explained as the following steps: 1) sweep model is a bubble pushed by the inertial force of water flow. The viscous force of water shears the surface of the bubble. The effect of both forces, the bubble changes its shape. Then trailing vortex starts to appear in near bubble tail. The second flow of water is in around of the bubble to strengthen the vortex energy density that causes fragments to detach from the parent bubble; 2) stretching model, the apparent bubble has high momentum force infiltrated in stagnant water depth and bubble ends are stretched out by the inertial force of the bubble and viscous force of water. The bubble surface has experienced stretching and tearing become splitting away. Based on the finding, the breakup process is highly dependent on the momentum of water flow, which triggers the secondary flow as the initial process of vortex flow, and it causes the tear of the bubble surface due to angular momentum","PeriodicalId":360260,"journal":{"name":"Aerospace Engineering eJournal","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116762791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of the Combined Method to De-Orbit Space Objects Using an Electric Rocket Propulsion System","authors":"A. Golubek, M. Dron’, L. Dubovik, Andrii Dreus, O. Kulyk, P. Khorolskiy","doi":"10.15587/1729-4061.2020.210378","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.210378","url":null,"abstract":"A method has been developed for the combined de-orbiting of large-size objects of space debris from low-Earth orbits using an electro-rocket propulsion system as an active de-orbiting means. A principal de-orbiting technique has been devised, which takes into consideration the patterns of using an electric rocket propulsion system in comparison with the sustainer rocket propulsion system. A procedure for determining the parameters of the de-orbiting scheme has been worked out, such as the minimum total speed and the time of the start of the de-orbiting process, which ensures its achievement. The proposed procedure takes into consideration the impact exerted on the process of the de-orbiting by the ballistic factor of the object, the height of the initial orbit, and the phase of solar activity at the time of the de-orbiting onset. The actual time constraints on battery discharge have been accounted for, as well as on battery charge duration, and active operation of the control system. The process of de-orbiting a large-size object of space debris has been simulated by using the combined method involving an electro-rocket propulsion system. The impact of the initial orbital altitude, ballistic coefficient, and the phase of solar activity on the energy costs of the de-orbiting process have been investigated. The dependences have been determined of the optimal values of a solar activity phase, in terms of energy costs, at the moment of the de-orbiting onset, and the total velocity, required to ensure the de-orbiting, on the altitude of the initial orbit and ballistic factor. These dependences are of practical interest in the tasks of designing the means of the combined de-orbiting involving an electric rocket propulsion system. The dependences of particular derivatives from the increment of a velocity pulse to the gain in the ballistic factor on the altitude of the initial orbit have been established. The use of these derivatives is also of practical interest to assess the effect of unfolding an aerodynamic sailing unit","PeriodicalId":360260,"journal":{"name":"Aerospace Engineering eJournal","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129590961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biomechanics of Vascular Plant as Template for Engineering Design","authors":"Mukesh Roy, F. Mathew, A. Prasad","doi":"10.2139/ssrn.3568076","DOIUrl":"https://doi.org/10.2139/ssrn.3568076","url":null,"abstract":"Abstract Plants are biocomposites with a hierarchical organization and multifunctionality with several unique characteristics different from animals (lack of motion and neurological control). Consequently, a stronger correlation is expected between plant structure, function, and mechanical response. Insights into these changes can have broad implications in bioinspired design, biobased material development, and precision agriculture. We use nanomechanical methods to investigate structural and compositional changes in sunflower plants at longitudinal stages of growth. Specifically, we use Scanning Electron Microscopy for microstructural analysis and Raman Spectroscopy and Optical Microscopy for compositional analysis. These studies together revealed several aspects of longitudinal growth. Specifically, the rapid plant growth during the vegetative stage (28% from week 4 to week 6) significantly slows (8%) during the transition to the reproductive stage (week 6 to week 8) and beyond. During the transition period, the thickness of the vascular zone increases significantly (28%), accompanied by modest thickening of cell walls (8%) and increases in cell diameter (4%), all of which impacting fluid flow dynamics. The increase in the vascular zone comes with a corresponding decrease internal flexible hydraulic chamber (17%), indicating the underlying mechanics of loss of flexibility. Raman spectroscopy revealed a high concentration of metabolites (molybdenum sulfide and crocetin), which are responsible for stress signaling and plant defense in the early stages of growth. Together, the study is first of its kind to quantify structure-composition changes of stem growth, Several engineering implications of the insight is discussed for applications varying from bioinspired design, biocomposites, and devices for precision agriculture.","PeriodicalId":360260,"journal":{"name":"Aerospace Engineering eJournal","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122375089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative Study of Mixture Model and Eulerian Model used in Hydro Cyclone with the Help of CFD Simulation","authors":"Indrashis Saha, Tathagata Mukherjee, Richa Pandey","doi":"10.2139/ssrn.3753865","DOIUrl":"https://doi.org/10.2139/ssrn.3753865","url":null,"abstract":"Due to the accuracy of numerical calculation of fluid flow inside a hydro cyclone can be obtained using Computational Fluid Dynamics (CFD), highly modified super computers are used to simulate the fluid flow and track particle motion inside a hydro cyclone. This paper deals with the numerical study using three multiphase models viz. Volume of fluid, Mixture and Eulerian model. The dimensions of the hydrocyclone taken into consideration for numerical analysis are same as considered by Rajamani. Validation of axial and tangential velocities at different strategically decided axial stations, RMS axial and tangential velocity profiles of the hydro cyclone is done using Reynolds Stress Model (RSM). The hydro cyclone model has been designed in Creo 3.0 using the same dimensions which later was imported to CFD for meshing. Fine hexagonal mesh numbering up to 5 lacs were constructed to obtain optimum results. Fluid flow was allowed to be developed in ANSYS FLUENT 16.2. Entire simulation took 96 hours to generate results and track particle movements inside the hydro cyclone. The particle tracking has been done using three multiphase model. The first being the volume of fluid was used for validation purposes and the comparison of the Mixture and Eulerian model are the basic focus of this research work. Conclusive results indicate that usage of different multiphase model does not result in variation in particle motion. The slight variation in grade efficiency values is hardly noticeable. The Mixture model and Eulerian model predict lower separation efficiency as compared with Volume of fluid multiphase model.","PeriodicalId":360260,"journal":{"name":"Aerospace Engineering eJournal","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121071786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Steady Plane Poiseuille Flow of Viscous Incompressible Fluid between Two Porous Parallel Plates in Magnetic Field","authors":"Dr. Anand Swrup Sharma","doi":"10.2139/ssrn.3637386","DOIUrl":"https://doi.org/10.2139/ssrn.3637386","url":null,"abstract":"In this paper we have investigated the steady plane Poiseuille flow of viscous incompressible fluid between two porous parallel plates in magnetic field. We have studied the velocity, average velocity, shear stress, skin frictions, the volumetric flow, drag coefficients and stream lines.","PeriodicalId":360260,"journal":{"name":"Aerospace Engineering eJournal","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121328480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hypersonic Flow Past Over an Elliptic Nose Cone Configurations: International Conference on Recent Trends in Artificial Intelligence, IOT, Smart Cities & Applications (ICAISC-2020)","authors":"Ashish Narayan, Sanjay Kumar, Pramod Pal, S. Pandey, Hirawati Hansdah, Ashok Kumar .","doi":"10.2139/ssrn.3621618","DOIUrl":"https://doi.org/10.2139/ssrn.3621618","url":null,"abstract":"The present work provides a detailed study of the hypersonic flow over elliptical nose cones at a Mach number of 5.8, numerically. The main focus of the paper is to determine parameters of the nose cones which provide minimum aerodynamic drag and heating. The conjugate heat transfer method is used to examine aerodynamic heat transfer between gas and surface accommodations for different fineness ratios at zero angle of attack. It is observed that for higher fineness ratio provide minimum drag. It also shows the detailed comparison of the flow/shock features in the vicinity of the elliptical nose cones for different fineness ratios in order to determine its influence on aerodynamic drag and heating. It is also noticed that the aerodynamic heating is almost same for all fineness ratios. In general, the present study reveals that at higher fineness ratios are preferred for achieving aerodynamic characteristics in hypervelocity vehicles.","PeriodicalId":360260,"journal":{"name":"Aerospace Engineering eJournal","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127694465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neural Networks for the Joint Development of Individual Payments and Claim Incurred","authors":"L. Delong, Mario V. Wuthrich","doi":"10.2139/ssrn.3545420","DOIUrl":"https://doi.org/10.2139/ssrn.3545420","url":null,"abstract":"The goal of this paper is to develop regression models and postulate distributions which can be used in practice to describe the joint development process of individual claim payments and claim incurred. We apply neural networks to estimate our regression models. As regressors we use the whole claim history of incremental payments and claim incurred, as well as any relevant feature information which is available to describe individual claims and their development characteristics. Our models are calibrated and tested on a real data set, and the results are benchmarked with the Chain-Ladder method. Our analysis focuses on the development of the so-called Reported But Not Settled (RBNS) claims. We show benefits of using deep neural network and the whole claim history in our prediction problem.","PeriodicalId":360260,"journal":{"name":"Aerospace Engineering eJournal","volume":"658 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115123097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}