M. Abshirini, Mohammad Charara, M. Saha, M. Altan, Yingtao Liu
Flexible and sensitive strain sensors can be utilized as wearable sensors and electronic devices in a wide range of applications, such as personal health monitoring, sports performance, and electronic skin. This paper presents the fabrication of a highly flexible and sensitive strain sensor by 3D printing an electrically conductive polydimethylsiloxane (PDMS)/multi-wall carbon nanotube (MWNT) nanocomposite on a PDMS substrate. To maximize the sensor’s gauge factor, the effects of MWNT concentration on the strain sensing function in nanocomposites are evaluated. Critical 3D printing and curing parameters, such as 3D printing nozzle diameter and nanocomposites curing temperature, are explored to achieve the highest piezoresistive response, showing that utilizing a smaller deposition nozzle size and higher curing temperature can result in a higher gauge factor. The optimized 3D printed nanocomposite sensor’s sensitivity is characterized under cyclic tensile loads at different maximum strains and loading rates. A linear piezoresistive response is observed up to 70% strain with an average gauge factor of 12, pointing to the sensor’s potential as a flexible strain sensor. In addition, the sensing function is almost independent of the applied load rate. The fabricated sensors are attached to a glove and used as a wearable sensor by detecting human finger and wrist motion. The results indicate that this 3D printed functional nanocomposite shows promise in a broad range of applications, including wearable and skin mounted sensors.
{"title":"Optimization of 3D Printed Elastomeric Nanocomposites for Flexible Strain Sensing Applications","authors":"M. Abshirini, Mohammad Charara, M. Saha, M. Altan, Yingtao Liu","doi":"10.1115/imece2019-11467","DOIUrl":"https://doi.org/10.1115/imece2019-11467","url":null,"abstract":"\u0000 Flexible and sensitive strain sensors can be utilized as wearable sensors and electronic devices in a wide range of applications, such as personal health monitoring, sports performance, and electronic skin. This paper presents the fabrication of a highly flexible and sensitive strain sensor by 3D printing an electrically conductive polydimethylsiloxane (PDMS)/multi-wall carbon nanotube (MWNT) nanocomposite on a PDMS substrate. To maximize the sensor’s gauge factor, the effects of MWNT concentration on the strain sensing function in nanocomposites are evaluated. Critical 3D printing and curing parameters, such as 3D printing nozzle diameter and nanocomposites curing temperature, are explored to achieve the highest piezoresistive response, showing that utilizing a smaller deposition nozzle size and higher curing temperature can result in a higher gauge factor. The optimized 3D printed nanocomposite sensor’s sensitivity is characterized under cyclic tensile loads at different maximum strains and loading rates. A linear piezoresistive response is observed up to 70% strain with an average gauge factor of 12, pointing to the sensor’s potential as a flexible strain sensor. In addition, the sensing function is almost independent of the applied load rate. The fabricated sensors are attached to a glove and used as a wearable sensor by detecting human finger and wrist motion. The results indicate that this 3D printed functional nanocomposite shows promise in a broad range of applications, including wearable and skin mounted sensors.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126473903","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}
This paper is concerned with the aeroelastic modeling and analysis of high aspect ratio wings with large torsional deflections with different fidelity structural models. The approach for structural modeling presented here is based on linear and nonlinear theories. The linear theories are based on the slender-straight wing and bending-torsion beam finite element formulations. The nonlinear theory is based on the nonlinear finite element model with only a torsional rotation degree of freedom to study the static aeroelastic behavior. The aerodynamic theory used for aeroelastic coupling is ESDU 95010 [1], which uses steady lifting-surface theory based on Multhopp-Richardson’s solution to provide the spanwise loading of lifting surfaces with camber and twist. Analyses are performed with three different structural models coupled with ESDU for simple plate-like wing models. The results of linear structural models are verified with MSC NASTRAN® and the nonlinear structural model results are verified with the work of Trahair [2]. Linear aeroelastic models are compared with the MSC NASTRAN® solution performed by SOL144. Significant differences in torsional deflection of tip location are observed between the linear and the nonlinear solution methodologies. The linear theory is found to be conservative for the aeroelastic analysis of high aspect ratio wings.
{"title":"Aeroelastic Modeling and Analysis of High Aspect Ratio Wings With Different Fidelity Structural Models","authors":"Gökçen Çiçek, A. Kayran","doi":"10.1115/imece2019-11483","DOIUrl":"https://doi.org/10.1115/imece2019-11483","url":null,"abstract":"\u0000 This paper is concerned with the aeroelastic modeling and analysis of high aspect ratio wings with large torsional deflections with different fidelity structural models.\u0000 The approach for structural modeling presented here is based on linear and nonlinear theories. The linear theories are based on the slender-straight wing and bending-torsion beam finite element formulations. The nonlinear theory is based on the nonlinear finite element model with only a torsional rotation degree of freedom to study the static aeroelastic behavior. The aerodynamic theory used for aeroelastic coupling is ESDU 95010 [1], which uses steady lifting-surface theory based on Multhopp-Richardson’s solution to provide the spanwise loading of lifting surfaces with camber and twist.\u0000 Analyses are performed with three different structural models coupled with ESDU for simple plate-like wing models.\u0000 The results of linear structural models are verified with MSC NASTRAN® and the nonlinear structural model results are verified with the work of Trahair [2]. Linear aeroelastic models are compared with the MSC NASTRAN® solution performed by SOL144. Significant differences in torsional deflection of tip location are observed between the linear and the nonlinear solution methodologies. The linear theory is found to be conservative for the aeroelastic analysis of high aspect ratio wings.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131696321","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}
This paper presents a semi-empirical approach to estimate the flight dynamics and stability derivatives of in-flight morphed platforms. Morphing can be a result of either planned design choices to optimize performance during the different phases of flight, or unplanned events such as wing damage induced from MANPADS or from a midair collision. Mass, mass center, stiffness, and shape changes caused by morphing do not always allow vehicle symmetry to be preserved, therefore a new semi-empirical approach is developed that includes effects of asymmetry. This new approach, and the additional stability derivatives formulated in this research, should prove useful and must be included in the accurate evaluation of in-flight morphing vehicles and in development of flight simulations.
{"title":"A Semi-Empirical Approach to Determine Dynamic Stability of In-Flight Morphing Platforms","authors":"T. Marchelli, N. Sarigul-Klijn","doi":"10.1115/imece2019-10274","DOIUrl":"https://doi.org/10.1115/imece2019-10274","url":null,"abstract":"\u0000 This paper presents a semi-empirical approach to estimate the flight dynamics and stability derivatives of in-flight morphed platforms. Morphing can be a result of either planned design choices to optimize performance during the different phases of flight, or unplanned events such as wing damage induced from MANPADS or from a midair collision. Mass, mass center, stiffness, and shape changes caused by morphing do not always allow vehicle symmetry to be preserved, therefore a new semi-empirical approach is developed that includes effects of asymmetry. This new approach, and the additional stability derivatives formulated in this research, should prove useful and must be included in the accurate evaluation of in-flight morphing vehicles and in development of flight simulations.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127188179","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}
Based on the well-known nonlinear hyperelasticity theory and by using the Carrera Unified Formulation (CUF) as well as a total Lagrangian approach, the unified theory of slightly compressible elastomeric structures including geometrical and physical nonlinearities is developed in this work. By exploiting CUF, the principle of virtual work and a finite element approximation, nonlinear governing equations corresponding to the slightly compressible elastomeric structures are straightforwardly formulated in terms of the fundamental nuclei, which are independent of the theory approximation order. Accordingly, the explicit forms of the secant and tangent stiffness matrices of the unified 1D beam and 2D plate elements are derived by using the three-dimensional Cauchy-Green deformation tensor and the nonlinear constitutive equation for slightly incompressible hyperelastic materials. Several numerical assessments are conducted, including uniaxial tension nonlinear response of rectangular elastomeric beams. Our numerical findings demonstrate the capabilities of the CUF model to calculate the large-deformation equilibrium curves as well as the stress distributions with high accuracy.
{"title":"Large-Deformation Analysis of Elastomeric Structures by Carrera Unified Formulation","authors":"E. Carrera, A. Pagani, Bin Wu, M. Filippi","doi":"10.1115/imece2019-11364","DOIUrl":"https://doi.org/10.1115/imece2019-11364","url":null,"abstract":"Based on the well-known nonlinear hyperelasticity theory and by using the Carrera Unified Formulation (CUF) as well as a total Lagrangian approach, the unified theory of slightly compressible elastomeric structures including geometrical and physical nonlinearities is developed in this work. By exploiting CUF, the principle of virtual work and a finite element approximation, nonlinear governing equations corresponding to the slightly compressible elastomeric structures are straightforwardly formulated in terms of the fundamental nuclei, which are independent of the theory approximation order. Accordingly, the explicit forms of the secant and tangent stiffness matrices of the unified 1D beam and 2D plate elements are derived by using the three-dimensional Cauchy-Green deformation tensor and the nonlinear constitutive equation for slightly incompressible hyperelastic materials. Several numerical assessments are conducted, including uniaxial tension nonlinear response of rectangular elastomeric beams. Our numerical findings demonstrate the capabilities of the CUF model to calculate the large-deformation equilibrium curves as well as the stress distributions with high accuracy.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122308950","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}
This work presents structural optimization studies of aluminum and composite material horizontal tail plane of a helicopter by using MSC. NASTRAN SOL200 optimization capabilities. Structural design process starts from conceptual design phase, and structural layout design is performed by using CATIA. In the preliminary design phase, study focuses on the minimum weight optimization with multiple design variables and similar constraints for both materials. Aerodynamic load calculation is performed using ANSYS and the finite element model of the horizontal tail plane is created by using MSC.PATRAN. According to the characteristics of materials, design variables are chosen. For the aluminum horizontal tail, thickness and flange areas are used as the design variables; and for composite horizontal tail, attention is mainly focused on the ply numbers and ply orientation angles of the laminated composite panels. By considering the manufacturability issues, discrete design variables are used. For three different mesh densities, different initial values of the design variables, and similar design constraints, optimizations are repeated and the results of optimizations are examined and compared with each other. In the optimizations performed, constraints are taken as strength and local buckling constraints. It is shown that the optimization methodology used in this study gives confident results for optimizing structures in the preliminary design phase.
{"title":"Comparative Structural Optimization Study of Composite and Aluminum Horizontal Tail Plane of a Helicopter","authors":"Bertan Arpacioglu, A. Kayran","doi":"10.1115/imece2019-11153","DOIUrl":"https://doi.org/10.1115/imece2019-11153","url":null,"abstract":"\u0000 This work presents structural optimization studies of aluminum and composite material horizontal tail plane of a helicopter by using MSC. NASTRAN SOL200 optimization capabilities. Structural design process starts from conceptual design phase, and structural layout design is performed by using CATIA. In the preliminary design phase, study focuses on the minimum weight optimization with multiple design variables and similar constraints for both materials. Aerodynamic load calculation is performed using ANSYS and the finite element model of the horizontal tail plane is created by using MSC.PATRAN. According to the characteristics of materials, design variables are chosen. For the aluminum horizontal tail, thickness and flange areas are used as the design variables; and for composite horizontal tail, attention is mainly focused on the ply numbers and ply orientation angles of the laminated composite panels. By considering the manufacturability issues, discrete design variables are used. For three different mesh densities, different initial values of the design variables, and similar design constraints, optimizations are repeated and the results of optimizations are examined and compared with each other. In the optimizations performed, constraints are taken as strength and local buckling constraints. It is shown that the optimization methodology used in this study gives confident results for optimizing structures in the preliminary design phase.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125898038","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}
Unmanned aerial vehicle (UAV), is an unmanned aircraft operated by radio remote control equipment and self-contained program control device. When Unmanned Aerial Vehicle is on mission, its location information needs to be acquired to navigate it. Based on the research background of Unmanned Aerial Vehicle navigation information measurement, a passive integrated navigation mode of Inertial / Altimeter / Infrared / Geomagnetism Navigation method is designed in this paper. Firstly, several methods for Unmanned Aerial Vehicle navigation, including geomagnetic navigation, infrared navigation, inertial navigation and altimeter measurement, are introduced, and the advantages and disadvantages of various navigation methods are presented. Secondly, aiming at the problem that the output of barometric altimeter is affected by temperature and pressure, a temperature and pressure compensation model of barometric altimeter is established. Then, the attitude angle, velocity and position measurement models of inertial, infrared and geomagnetic navigation are established respectively. Finally, the data information of inertial / altimeter / infrared / geomagnetism measurement model is fused by extended Kalman filter and Unscented Kalman filter, and the signals processed by the two filters are compared. The reliability of the integrated navigation method is verified by simulation. This method has remarkable effect on improving the navigation accuracy of UAV and can make UAV suitable for many applications. It is simple and effective, and has wide application prospects.
{"title":"An Inertial / Altimetric / Infrared / Geomagnetic Integrated Navigation Method for Unmanned Aerial Vehicles","authors":"Zilu He, X. Bu, Yihan Cao, Miaomiao Xu","doi":"10.1115/imece2019-10948","DOIUrl":"https://doi.org/10.1115/imece2019-10948","url":null,"abstract":"\u0000 Unmanned aerial vehicle (UAV), is an unmanned aircraft operated by radio remote control equipment and self-contained program control device. When Unmanned Aerial Vehicle is on mission, its location information needs to be acquired to navigate it. Based on the research background of Unmanned Aerial Vehicle navigation information measurement, a passive integrated navigation mode of Inertial / Altimeter / Infrared / Geomagnetism Navigation method is designed in this paper. Firstly, several methods for Unmanned Aerial Vehicle navigation, including geomagnetic navigation, infrared navigation, inertial navigation and altimeter measurement, are introduced, and the advantages and disadvantages of various navigation methods are presented. Secondly, aiming at the problem that the output of barometric altimeter is affected by temperature and pressure, a temperature and pressure compensation model of barometric altimeter is established. Then, the attitude angle, velocity and position measurement models of inertial, infrared and geomagnetic navigation are established respectively. Finally, the data information of inertial / altimeter / infrared / geomagnetism measurement model is fused by extended Kalman filter and Unscented Kalman filter, and the signals processed by the two filters are compared. The reliability of the integrated navigation method is verified by simulation. This method has remarkable effect on improving the navigation accuracy of UAV and can make UAV suitable for many applications. It is simple and effective, and has wide application prospects.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127971194","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}
In this paper we discuss the role of different image segmentation methods that are used for the analysis of the micro computed tomography (micro-CT) data of damage in the carbon fiber reinforced polymer (CFRP) composites due to low velocity impact. Segmentation is one of the most critical steps in the image processing of the three dimensional (3D) CT data and accurate assessment of the damage from CT data depends to a great extent on the image segmentation. We have extensively studied low velocity impact damage in the CFRP composites using 3D CT. CFRP textile composite laminates were impacted using an Instron 8200 Dynatup drop-weight impact machine. ZEISS METROTOM 1500 CT scanner was used to evaluate internal impact damage. VGStudio MAX was used for reconstruction of CT images. Different segmentation procedures were used during image processing of the CT images. Differences in the estimates of the damage zone obtained using different segmentation techniques have been assessed.
{"title":"On the Role of Segmentation in the Analysis of Micro-CT Data of Impact Damage in the CFRP Composites","authors":"O. Zhupanska","doi":"10.1115/imece2019-11037","DOIUrl":"https://doi.org/10.1115/imece2019-11037","url":null,"abstract":"\u0000 In this paper we discuss the role of different image segmentation methods that are used for the analysis of the micro computed tomography (micro-CT) data of damage in the carbon fiber reinforced polymer (CFRP) composites due to low velocity impact. Segmentation is one of the most critical steps in the image processing of the three dimensional (3D) CT data and accurate assessment of the damage from CT data depends to a great extent on the image segmentation. We have extensively studied low velocity impact damage in the CFRP composites using 3D CT. CFRP textile composite laminates were impacted using an Instron 8200 Dynatup drop-weight impact machine. ZEISS METROTOM 1500 CT scanner was used to evaluate internal impact damage. VGStudio MAX was used for reconstruction of CT images. Different segmentation procedures were used during image processing of the CT images. Differences in the estimates of the damage zone obtained using different segmentation techniques have been assessed.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129501818","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}
Wu Bin, Li Mingzhi, Liu Xiucheng, Wang Heying, He Cunfu, Liu Zongfa
In this paper, a nondestructive evaluation technique based on highly nonlinear solitary waves (HNSWs) is proposed to monitor the curing process of adhesive for composite/metal bonded structure. HNSWs are mechanical waves with high energy intensity and non-distortive nature which can form and propagate in a nonlinear system, such as a one-dimensional granular chain. In the present study, a finite element model of the one-dimensional granular chain is established with the commercial software Abaqus, to study the reflection behavior of HNSWs at the interface between the particle at the end of chain and the sample. The simulation results show that the time of flight (TOF) of the primary reflected solitary wave decreases with the stiffness of the sample increases, and the amplitude ratio (AR) between the primary reflected solitary wave and the incident solitary wave increases. An HNSWs transducer based on the one-dimensional granular chain is designed and fabricated. The relationship between the characteristic parameters of the primary reflected solitary wave (TOF and AR) and the curing time of adhesive for a composite/metal bonded structure is experimentally investigated. The experiment results suggest that the TOF decreases and the AR increases as the epoxy cures. The experimental results are in good agreement with the simulation results. This study provides a new characterization method for monitoring the curing process of adhesive for composite/metal bonded structure.
{"title":"Cure Monitoring of Adhesive for Composite/Metal Bonded Structure Based on Highly Nonlinear Solitary Waves","authors":"Wu Bin, Li Mingzhi, Liu Xiucheng, Wang Heying, He Cunfu, Liu Zongfa","doi":"10.1115/imece2019-10717","DOIUrl":"https://doi.org/10.1115/imece2019-10717","url":null,"abstract":"\u0000 In this paper, a nondestructive evaluation technique based on highly nonlinear solitary waves (HNSWs) is proposed to monitor the curing process of adhesive for composite/metal bonded structure. HNSWs are mechanical waves with high energy intensity and non-distortive nature which can form and propagate in a nonlinear system, such as a one-dimensional granular chain. In the present study, a finite element model of the one-dimensional granular chain is established with the commercial software Abaqus, to study the reflection behavior of HNSWs at the interface between the particle at the end of chain and the sample. The simulation results show that the time of flight (TOF) of the primary reflected solitary wave decreases with the stiffness of the sample increases, and the amplitude ratio (AR) between the primary reflected solitary wave and the incident solitary wave increases. An HNSWs transducer based on the one-dimensional granular chain is designed and fabricated. The relationship between the characteristic parameters of the primary reflected solitary wave (TOF and AR) and the curing time of adhesive for a composite/metal bonded structure is experimentally investigated. The experiment results suggest that the TOF decreases and the AR increases as the epoxy cures. The experimental results are in good agreement with the simulation results. This study provides a new characterization method for monitoring the curing process of adhesive for composite/metal bonded structure.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131102406","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}
In this work the performance of a valveless pulsejet with two different fuels and several fuel mass flows was numerically estimated. Results for pressures, velocities, traction and pollutant formation are presented. Even though this type of engine has many advantages over the conventional types, it still has many problems for application in civil aviation due to noise levels. Although having a very simple construction, operation is not completely understood, so studies continue to be made in order to have a better knowledge of the physics behind operation. For engine sizing, was performed a calculation procedure based on data of existing engines and equations reported in the literature. The pulsejet operation was then simulated using ANSYS Fluent 16.2. Simulations were 2D transient, three different fuel flows were analysed: 0.04 kg/s, 0.06 kg/s and 0.1 kg/s and two fuels used: propane and methane. For propane an additional case was defined, being the fuel mass flow of 0.12 kg/s. The results obtained are similar for the two fuels, the variables have the same behaviour with the variation of the fuel flow except for the operating frequency.
{"title":"Influence of Fuel on a Valveless Pulsejet Engine Performance and Pollutant Emissions","authors":"A. Melo, F. Brójo","doi":"10.1115/imece2019-11229","DOIUrl":"https://doi.org/10.1115/imece2019-11229","url":null,"abstract":"\u0000 In this work the performance of a valveless pulsejet with two different fuels and several fuel mass flows was numerically estimated. Results for pressures, velocities, traction and pollutant formation are presented. Even though this type of engine has many advantages over the conventional types, it still has many problems for application in civil aviation due to noise levels. Although having a very simple construction, operation is not completely understood, so studies continue to be made in order to have a better knowledge of the physics behind operation. For engine sizing, was performed a calculation procedure based on data of existing engines and equations reported in the literature. The pulsejet operation was then simulated using ANSYS Fluent 16.2. Simulations were 2D transient, three different fuel flows were analysed: 0.04 kg/s, 0.06 kg/s and 0.1 kg/s and two fuels used: propane and methane. For propane an additional case was defined, being the fuel mass flow of 0.12 kg/s. The results obtained are similar for the two fuels, the variables have the same behaviour with the variation of the fuel flow except for the operating frequency.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123597948","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}
Bleed air is brought into aircraft cabins in order to maintain the quality of the air for passenger and crew health and comfort. The bleed air can be contaminated by oil due to oil seal leaks in the compressor which have been reported randomly and generated significant public interest. Previous studies have measured the particulate size distribution in the bleed air entering the cabin, but never distinguished the type and material of the particulate matter (PM). The particulates could be potentially hazardous oil droplets from the oil seal leaks, water droplets due the presence of fog generated by the cooling system, and so on. In this study we propose a novel technique using light scattering technology to distinguish between contaminant types. This technique uses size and complex index of refraction as the measure. Since each material has a distinct index of refraction, by determining the index of refraction, our proposed low-cost detector could distinguish the compound in the aerosol as well as determine the particle size simultaneously.
{"title":"Low-Cost Particulate Detection in Bleed Air","authors":"Mir Seliman Waez, S. Eckels, C. Sorensen","doi":"10.1115/imece2019-10460","DOIUrl":"https://doi.org/10.1115/imece2019-10460","url":null,"abstract":"\u0000 Bleed air is brought into aircraft cabins in order to maintain the quality of the air for passenger and crew health and comfort. The bleed air can be contaminated by oil due to oil seal leaks in the compressor which have been reported randomly and generated significant public interest. Previous studies have measured the particulate size distribution in the bleed air entering the cabin, but never distinguished the type and material of the particulate matter (PM). The particulates could be potentially hazardous oil droplets from the oil seal leaks, water droplets due the presence of fog generated by the cooling system, and so on. In this study we propose a novel technique using light scattering technology to distinguish between contaminant types. This technique uses size and complex index of refraction as the measure. Since each material has a distinct index of refraction, by determining the index of refraction, our proposed low-cost detector could distinguish the compound in the aerosol as well as determine the particle size simultaneously.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130098117","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}
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