Pub Date : 2017-03-10DOI: 10.4172/2168-9792.1000185
Kostopoulos V, Kotzakolios T, Vlachos De
Composite lattice structures are shells that are reinforced by unidirectional helical and hoop ribs. Their main advantage over contemporary composite structures is their superior stiffness to mass ratio. However, their application in industry is still limited. In this paper, the lattice structure concept was applied for the case of a small business aircraft. Emphasis here is given at the initial stages of the design. More specifically, the buckling modes for bending loads were calculated by utilizing a continum unit cell model which was correlated with finite element models for a cylindrical small fuselage structure and two scaled down versions.
{"title":"The Buckling Response of Lattice Fuselage Structures: Validation of Finite Element Models by Using Smeared Unit Cell Analytical Methodology","authors":"Kostopoulos V, Kotzakolios T, Vlachos De","doi":"10.4172/2168-9792.1000185","DOIUrl":"https://doi.org/10.4172/2168-9792.1000185","url":null,"abstract":"Composite lattice structures are shells that are reinforced by unidirectional helical and hoop ribs. Their main advantage over contemporary composite structures is their superior stiffness to mass ratio. However, their application in industry is still limited. In this paper, the lattice structure concept was applied for the case of a small business aircraft. Emphasis here is given at the initial stages of the design. More specifically, the buckling modes for bending loads were calculated by utilizing a continum unit cell model which was correlated with finite element models for a cylindrical small fuselage structure and two scaled down versions.","PeriodicalId":356774,"journal":{"name":"Journal of Aeronautics and Aerospace Engineering","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115834930","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}
Pub Date : 2017-01-08DOI: 10.4172/2168-9792.1000182
L. Mazzola, G. Bruno, B. Galasso, Quaranta, F. Albano, A. Auletta, Cori
Ice adhesion on critical aircraft surfaces is a serious potential hazard that runs the risk of causing accidents. Frozen contaminants cause rough and uneven surfaces which will disturb smooth air flow and greatly degrade the ability of the wing to generate lift and increasing drag. Amongst icing mitigation systems, passive anti-icing coatings represent a challenge to reduce the ice nucleation and growth, reducing the power consumption of the active de-icing systems and consequently the fuel consumption. In this work the advanced properties and effectiveness of the new multifunctional coating with ice-phobic and aesthetical properties are described. In particular advanced morphological characterizations based on Atomic Force Microscopy and Laser Scanning Microscopy measurements as well as subsequent Power Spectral Density analysis were performed to evaluate the surface roughness. Contact angle measurements were executed in order to determine the wettability and surface free energy as well as work of adhesion in flight conditions. In addition, dynamic analysis of the impact of single water droplets on the new multifunctional coating and the classical livery coating were performed in order to demonstrate the different physical behavior during the impingement. It was also demonstrated that the new multifunctional coating overcome the environmental test similarly to the commercial livery coating in accordance with the aeronautical specification. Finally, two NACA symmetric airfoils were design and developed using 3D printing technology. The surfaces were coated with a commercial coating in one case and with the new multifunctional coating in the other case. Both airfoils were tested in the Icing Wind Tunnel at different conditions in order to evaluate the effectiveness, in terms of reduction of accreted ice, of the new multifunctional coating respect to the commercial one. Tests demonstrated the reduction of accreted ice of 50% using the new multifunctional coating.
{"title":"Development and Technological Characterization of Multi-functional Aeronautical Coating From Lab-Scale to the Relevant Environment","authors":"L. Mazzola, G. Bruno, B. Galasso, Quaranta, F. Albano, A. Auletta, Cori","doi":"10.4172/2168-9792.1000182","DOIUrl":"https://doi.org/10.4172/2168-9792.1000182","url":null,"abstract":"Ice adhesion on critical aircraft surfaces is a serious potential hazard that runs the risk of causing accidents. \u0000 Frozen contaminants cause rough and uneven surfaces which will disturb smooth air flow and greatly degrade the \u0000 ability of the wing to generate lift and increasing drag. \u0000Amongst icing mitigation systems, passive anti-icing coatings represent a challenge to reduce the ice nucleation \u0000 and growth, reducing the power consumption of the active de-icing systems and consequently the fuel consumption. \u0000In this work the advanced properties and effectiveness of the new multifunctional coating with ice-phobic and \u0000 aesthetical properties are described. In particular advanced morphological characterizations based on Atomic Force Microscopy and Laser Scanning Microscopy measurements as well as subsequent Power Spectral Density analysis were performed to evaluate the surface roughness. \u0000Contact angle measurements were executed in order to determine the wettability and surface free energy as \u0000 well as work of adhesion in flight conditions. In addition, dynamic analysis of the impact of single water droplets on \u0000 the new multifunctional coating and the classical livery coating were performed in order to demonstrate the different \u0000 physical behavior during the impingement. \u0000It was also demonstrated that the new multifunctional coating overcome the environmental test similarly to the \u0000 commercial livery coating in accordance with the aeronautical specification. \u0000Finally, two NACA symmetric airfoils were design and developed using 3D printing technology. The surfaces \u0000 were coated with a commercial coating in one case and with the new multifunctional coating in the other case. Both \u0000 airfoils were tested in the Icing Wind Tunnel at different conditions in order to evaluate the effectiveness, in terms of \u0000 reduction of accreted ice, of the new multifunctional coating respect to the commercial one. Tests demonstrated the \u0000 reduction of accreted ice of 50% using the new multifunctional coating.","PeriodicalId":356774,"journal":{"name":"Journal of Aeronautics and Aerospace Engineering","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116146457","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}
Pub Date : 2017-01-05DOI: 10.4172/2168-9792.1000180
E. D. Donder, N. Crosby, M. Kruglanski, J. Andries, A. Devos, Christopher Perry, C. Borries, D. Martini, A. Glover, J. Luntama
Spacecraft operations are by nature complex and every satellite's operational environment poses a range of potential risks, often a unique combination for a given orbit. The implications of interruptions of operations, data transfer and service provision, are serious, both in terms of cost and capability, thus it is imperative to mitigate against all operational risks to the fullest extent possible. In the frame of its Space Situational Awareness (SSA) programme, the European Space Agency (ESA) is establishing a Space Weather Service Network to support end-users, in a wide range of affected sectors, in mitigating the effects of space weather on their systems, reducing costs and improving reliability. This service network is currently in a test and validation phase and encourages user engagement and feedback. The network is organised around five Expert Service Centres (ESCs) focusing on Solar Weather, Heliospheric Weather, Space Radiation Environment, Ionospheric Weather and Geomagnetic Conditions. Each ESC is connecting different expert groups, federating their space weather products, and ensuring the quality and consistency of the provided information. The service network also includes a central Data Centre and the SSA Space Weather Coordination Centre (SSCC). In this presentation we give an overview of the current status of the network (http://swe.ssa.esa.int/), the targeted end-user groups and Expert Service Centres with a focus on the space community.
{"title":"Services for Space Mission Support Within The ESA Space Situational Awareness Space Weather Service Network","authors":"E. D. Donder, N. Crosby, M. Kruglanski, J. Andries, A. Devos, Christopher Perry, C. Borries, D. Martini, A. Glover, J. Luntama","doi":"10.4172/2168-9792.1000180","DOIUrl":"https://doi.org/10.4172/2168-9792.1000180","url":null,"abstract":"Spacecraft operations are by nature complex and every satellite's operational environment poses a range of potential risks, often a unique combination for a given orbit. The implications of interruptions of operations, data transfer and service provision, are serious, both in terms of cost and capability, thus it is imperative to mitigate against all operational risks to the fullest extent possible. In the frame of its Space Situational Awareness (SSA) programme, the European Space Agency (ESA) is establishing a Space Weather Service Network to support end-users, in a wide range of affected sectors, in mitigating the effects of space weather on their systems, reducing costs and improving reliability. This service network is currently in a test and validation phase and encourages user engagement and feedback. The network is organised around five Expert Service Centres (ESCs) focusing on Solar Weather, Heliospheric Weather, Space Radiation Environment, Ionospheric Weather and Geomagnetic Conditions. Each ESC is connecting different expert groups, federating their space weather products, and ensuring the quality and consistency of the provided information. The service network also includes a central Data Centre and the SSA Space Weather Coordination Centre (SSCC). In this presentation we give an overview of the current status of the network (http://swe.ssa.esa.int/), the targeted end-user groups and Expert Service Centres with a focus on the space community.","PeriodicalId":356774,"journal":{"name":"Journal of Aeronautics and Aerospace Engineering","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121421313","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}
Pub Date : 2016-12-13DOI: 10.4172/2168-9792.1000179
N. ell-Mills
Buoyancy explains how planes fly. To fly a plane needs to displace a mass of air down equal to its own mass, each second. Planes are effectively floating on a cushion of air that the wings create by pushing air downwards. This is a similar explanation to how boats float according to Archimedes principle of buoyancy, and how birds fly by pushing air downwards. Correspondingly, this theory predicts that for all planes to fly, they must displace a mass of air down equal to its own mass each second. If the current equation for lift is adjusted to include “the distance down that air is displaced by the wing” Then a good estimate of the mass of air displaced by the wing (and thus buoyancy), is provided. Hence, the proposed new equation for lift is: Lift (Force) = Air Mass Displaced each second × Aircraft Velocity (i.e. F = mv) This theory is proposed as the current theories of flight have severe limitations and remain unproven. There is no scientific experiment on a real aircraft in realistic conditions that proves any theory to be correct. Pilots, aviation authorities, academics and engineers still debate the different theories of flight whereas; it is possible to prove buoyancy. Current theories of flight ignore buoyancy. This theory of flight has been presented to numerous pilots, engineers, and academics. No one has been able to provide a valid scientific argument or evidence to disprove it.
{"title":"Buoyancy Explains How Planes Fly","authors":"N. ell-Mills","doi":"10.4172/2168-9792.1000179","DOIUrl":"https://doi.org/10.4172/2168-9792.1000179","url":null,"abstract":"Buoyancy explains how planes fly. To fly a plane needs to displace a mass of air down equal to its own mass, \u0000 each second. Planes are effectively floating on a cushion of air that the wings create by pushing air downwards. \u0000This is a similar explanation to how boats float according to Archimedes principle of buoyancy, and how birds fly \u0000 by pushing air downwards. Correspondingly, this theory predicts that for all planes to fly, they must displace a mass \u0000 of air down equal to its own mass each second. \u0000If the current equation for lift is adjusted to include “the distance down that air is displaced by the wing” Then a \u0000 good estimate of the mass of air displaced by the wing (and thus buoyancy), is provided. Hence, the proposed new \u0000 equation for lift is: \u0000Lift (Force) = Air Mass Displaced each second × Aircraft Velocity (i.e. F = mv) \u0000This theory is proposed as the current theories of flight have severe limitations and remain unproven. There is \u0000 no scientific experiment on a real aircraft in realistic conditions that proves any theory to be correct. Pilots, aviation \u0000 authorities, academics and engineers still debate the different theories of flight whereas; it is possible to prove \u0000 buoyancy. Current theories of flight ignore buoyancy. \u0000This theory of flight has been presented to numerous pilots, engineers, and academics. No one has been able \u0000 to provide a valid scientific argument or evidence to disprove it.","PeriodicalId":356774,"journal":{"name":"Journal of Aeronautics and Aerospace Engineering","volume":"89 11","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114021752","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}
Pub Date : 2016-11-16DOI: 10.4172/2168-9792.1000178
Behbahani-Pour Mj, G. Radice
In all large passenger transport airplanes, halon fire bottles are used to extinguish fire in the cargo compartments. Halon as a fire-extinguishing agent, contributes to the destruction of stratospheric ozone in the atmosphere and it is banned in many countries. FAA considers halon 1301 as an effective firefighting agent due to its low toxicity and noncorrosive properties but because it damages the ozone layer, it has been phased out of production. However, it is still widely used on commercial aircraft until a suitable replacement is found. In this paper we will present an alternative approach to using halon 1301 as a fire fighting paradigm. In the proposed method, nitrogen is first extracted from the atmosphere by using the onboard air separator module it is then cooled, and pressurized into the cargo compartments to suppress any fire. Several methodologies can be used to increase the flow rate from the air separator module, to extinguish fire in cargo compartment.
{"title":"Cargo Compartment Fire Extinguishing System","authors":"Behbahani-Pour Mj, G. Radice","doi":"10.4172/2168-9792.1000178","DOIUrl":"https://doi.org/10.4172/2168-9792.1000178","url":null,"abstract":"In all large passenger transport airplanes, halon fire bottles are used to extinguish fire in the cargo compartments. Halon as a fire-extinguishing agent, contributes to the destruction of stratospheric ozone in the atmosphere and it is banned in many countries. FAA considers halon 1301 as an effective firefighting agent due to its low toxicity and noncorrosive properties but because it damages the ozone layer, it has been phased out of production. However, it is still widely used on commercial aircraft until a suitable replacement is found. In this paper we will present an alternative approach to using halon 1301 as a fire fighting paradigm. In the proposed method, nitrogen is first extracted from the atmosphere by using the onboard air separator module it is then cooled, and pressurized into the cargo compartments to suppress any fire. Several methodologies can be used to increase the flow rate from the air separator module, to extinguish fire in cargo compartment.","PeriodicalId":356774,"journal":{"name":"Journal of Aeronautics and Aerospace Engineering","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132631256","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}
Pub Date : 2016-10-31DOI: 10.4172/2168-9792.1000174
Behbahani-Pour Mj, G. Radice
Fuel leakage has the risk of being ignited by external ignition sources, and therefore it is important to detect any fuel leakage before the departure of the aircraft. Currently, there are no fuel leak detection systems installed on commercial aircrafts, to detect fuel tank leakage, while only a small number of more recent aircraft, have a fuel monitoring system, that generates a fuel leak-warning message in cockpit in the case of fuel imbalance between the tanks. The approach proposed in this paper requires the fuel vent ports on the wings to be replaced with fuel vent valves, which can be controlled to be in open or close position. The fuel vent valve will be in close position, when certain conditions are fulfilled (all the related fuel valves closed, pumps not operating, etc.), the fuel tank ullage area is then pressurized to 4 psi and the rate of change of the pressure is measured over a period. Several experiments have been conducted and, the result show that a continuous fuel leak of one liter per minute can be detected. Further experiments show that if the fuel tank is pressurized to higher pressures, a fuel leak can be detected sooner.
{"title":"Fuel Leak Detection on Large Transport Airplanes","authors":"Behbahani-Pour Mj, G. Radice","doi":"10.4172/2168-9792.1000174","DOIUrl":"https://doi.org/10.4172/2168-9792.1000174","url":null,"abstract":"Fuel leakage has the risk of being ignited by external ignition sources, and therefore it is important to detect any fuel leakage before the departure of the aircraft. Currently, there are no fuel leak detection systems installed on commercial aircrafts, to detect fuel tank leakage, while only a small number of more recent aircraft, have a fuel monitoring system, that generates a fuel leak-warning message in cockpit in the case of fuel imbalance between the tanks. The approach proposed in this paper requires the fuel vent ports on the wings to be replaced with fuel vent valves, which can be controlled to be in open or close position. The fuel vent valve will be in close position, when certain conditions are fulfilled (all the related fuel valves closed, pumps not operating, etc.), the fuel tank ullage area is then pressurized to 4 psi and the rate of change of the pressure is measured over a period. Several experiments have been conducted and, the result show that a continuous fuel leak of one liter per minute can be detected. Further experiments show that if the fuel tank is pressurized to higher pressures, a fuel leak can be detected sooner.","PeriodicalId":356774,"journal":{"name":"Journal of Aeronautics and Aerospace Engineering","volume":"115 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113997620","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}
Pub Date : 2016-10-31DOI: 10.4172/2168-9792.1000175
Yuvaraj George, K. Veeranjaneyulu
This paper proposes an idea of lift augmentation for conventional subsonic aircraft at low along with mathematical analysis. This paper mainly addresses certain changes in power plant requirements and performance characteristics of aircraft after implementation of buoyancy lift augmentation technique. There are certain factors which must be considered for practical implementation of it towards an aircraft without degrading its primary performance and mission profile. Those considerations are discussed with respect to total weight or overall weight of the aircraft and vital changes required in design, manufacturing and operation are addressed. This document also formulates a brief overview on changes that would occur in flight aerodynamic characteristics after the supplementation as well as its impact on flight performance parameters.
{"title":"Buoyancy Lift Augmentation","authors":"Yuvaraj George, K. Veeranjaneyulu","doi":"10.4172/2168-9792.1000175","DOIUrl":"https://doi.org/10.4172/2168-9792.1000175","url":null,"abstract":"This paper proposes an idea of lift augmentation for conventional subsonic aircraft at low along with mathematical analysis. This paper mainly addresses certain changes in power plant requirements and performance characteristics of aircraft after implementation of buoyancy lift augmentation technique. There are certain factors which must be considered for practical implementation of it towards an aircraft without degrading its primary performance and mission profile. Those considerations are discussed with respect to total weight or overall weight of the aircraft and vital changes required in design, manufacturing and operation are addressed. This document also formulates a brief overview on changes that would occur in flight aerodynamic characteristics after the supplementation as well as its impact on flight performance parameters.","PeriodicalId":356774,"journal":{"name":"Journal of Aeronautics and Aerospace Engineering","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129155832","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}
Pub Date : 2016-10-31DOI: 10.4172/2168-9792.1000176
Ahmed M. Diaa, M. El-Dosoky, A. Ma
Axial flow compressors have a limited operation range due to the difficulty of controlling the secondary flows. Therefore, a new design of vortex generators is considered in the current investigation to control the secondary flow losses and consequently enhance the compressor’s performance. Different sets of curved side vortex generators with varying configurations are studied to find their effect on the secondary flow losses. Numerical simulations of a three-dimensional compressible turbulent flow have been performed to explore the effect of vortex generators on the reduction of secondary flow losses. Based on the simulation results, the pressure, velocity, and streamline contours are presented to track the development of secondary flows in the compressor cascade. Thus, the total pressure loss and static pressure rise coefficients, blade deflection angles, and diffusion factors are estimated. Results indicate that vortex generators have a significant impact on secondary flow losses such as reducing the corner vortices, and improving the location of separation lines which are moving toward the trailing edge. At the cascade design point, it is found that vortex generators have a significant effect on the reduction of normalized total pressure loss which is evaluated to be up to 20.7%. Using vortex generators do not lead to a significant change in flow deflection and accordingly the off-design conditions will still be far from reached.
{"title":"Enhancing the Performance of an Axial Compressor Cascade using Vortex Generators","authors":"Ahmed M. Diaa, M. El-Dosoky, A. Ma","doi":"10.4172/2168-9792.1000176","DOIUrl":"https://doi.org/10.4172/2168-9792.1000176","url":null,"abstract":"Axial flow compressors have a limited operation range due to the difficulty of controlling the secondary flows. \u0000 Therefore, a new design of vortex generators is considered in the current investigation to control the secondary flow \u0000 losses and consequently enhance the compressor’s performance. Different sets of curved side vortex generators \u0000 with varying configurations are studied to find their effect on the secondary flow losses. Numerical simulations of a \u0000 three-dimensional compressible turbulent flow have been performed to explore the effect of vortex generators on the \u0000 reduction of secondary flow losses. Based on the simulation results, the pressure, velocity, and streamline contours \u0000 are presented to track the development of secondary flows in the compressor cascade. Thus, the total pressure loss \u0000 and static pressure rise coefficients, blade deflection angles, and diffusion factors are estimated. Results indicate \u0000 that vortex generators have a significant impact on secondary flow losses such as reducing the corner vortices, and \u0000 improving the location of separation lines which are moving toward the trailing edge. At the cascade design point, \u0000 it is found that vortex generators have a significant effect on the reduction of normalized total pressure loss which \u0000 is evaluated to be up to 20.7%. Using vortex generators do not lead to a significant change in flow deflection and \u0000 accordingly the off-design conditions will still be far from reached.","PeriodicalId":356774,"journal":{"name":"Journal of Aeronautics and Aerospace Engineering","volume":"365 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116638705","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}
Pub Date : 2016-10-31DOI: 10.4172/2168-9792.1000177
I. Shahin
New dry gas seal “DGS” groove geometry has been developed, using a verified three dimensional simulations. The effect of the various groove profiles; standard spiral, tapered-spiral, spiral with an annulus and tapered-spiral with an annulus were studied at wide range of operating speed. The results indicate that, tapered type spiral groove causes a reduction in opening force and in the leakage rate. In addition, increasing the taper angle reduces the temperature distribution inside the gas film and reduces the thermal stresses on the seal mating rings. The combined use of annuals and taper spiral groove decrease the leakage rate for spiral DGS with annular groove only. The final optimized spiral tapered seal with annuals reduces the leakage rate by 18.5% from standard seal, ensures uniform pressure distribution and hydrostatic lift at low speeds, resulting in low torque and reliable operating at start-up condition.
{"title":"Gas Seal Performance and Start up Condition Enhancing with Different Seal Groove Geometries","authors":"I. Shahin","doi":"10.4172/2168-9792.1000177","DOIUrl":"https://doi.org/10.4172/2168-9792.1000177","url":null,"abstract":"New dry gas seal “DGS” groove geometry has been developed, using a verified three dimensional simulations. The effect of the various groove profiles; standard spiral, tapered-spiral, spiral with an annulus and tapered-spiral with an annulus were studied at wide range of operating speed. The results indicate that, tapered type spiral groove causes a reduction in opening force and in the leakage rate. In addition, increasing the taper angle reduces the temperature distribution inside the gas film and reduces the thermal stresses on the seal mating rings. The combined use of annuals and taper spiral groove decrease the leakage rate for spiral DGS with annular groove only. The final optimized spiral tapered seal with annuals reduces the leakage rate by 18.5% from standard seal, ensures uniform pressure distribution and hydrostatic lift at low speeds, resulting in low torque and reliable operating at start-up condition.","PeriodicalId":356774,"journal":{"name":"Journal of Aeronautics and Aerospace Engineering","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131946076","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}
Pub Date : 2016-10-31DOI: 10.4172/2168-9792.1000173
S. Gangadharan, Baliga Sv, Sonawane Nh, P. Sathyanarayan, S. Kamdar
The area under crack for various aircraft composite structures can be effectively repaired using composite materials. Low velocity impact can cause barely visible damage to the interior structure of laminated composite. These impacts can cause delamination in composite materials. In this study, a finite element analysis was conducted using Abaqus/Explicit and the results of the analysis were compared to the experimental data from literature. E-glass/epoxy composite laminate was subjected to a low velocity impact test. To study the effect of patch repair, a composite patch was applied on a cracked laminate and a low velocity impact was then conducted on this model. The FEA results were validated with the experimental data and an approach to model an ideal composite patch shape was conducted. Different patch shapes like square, rectangle, circle and ellipse were designed and analysed on the crack by keeping the surface area of the patch common. All these patches were compared and an ideal patch shape was found for the model based on stress concentration on the patch. Finally, a parametric study was performed considering the change in impactor speed and impactor material on impact damage. The effectiveness of finite element analysis of low velocity impact on aircraft composite structures is demonstrated.
{"title":"Impact Analysis of Composite Repair Patches of Different Shapes at Low Velocities for Aircraft Composite Structures","authors":"S. Gangadharan, Baliga Sv, Sonawane Nh, P. Sathyanarayan, S. Kamdar","doi":"10.4172/2168-9792.1000173","DOIUrl":"https://doi.org/10.4172/2168-9792.1000173","url":null,"abstract":"The area under crack for various aircraft composite structures can be effectively repaired using composite materials. Low velocity impact can cause barely visible damage to the interior structure of laminated composite. These impacts can cause delamination in composite materials. In this study, a finite element analysis was conducted using Abaqus/Explicit and the results of the analysis were compared to the experimental data from literature. E-glass/epoxy composite laminate was subjected to a low velocity impact test. To study the effect of patch repair, a composite patch was applied on a cracked laminate and a low velocity impact was then conducted on this model. The FEA results were validated with the experimental data and an approach to model an ideal composite patch shape was conducted. Different patch shapes like square, rectangle, circle and ellipse were designed and analysed on the crack by keeping the surface area of the patch common. All these patches were compared and an ideal patch shape was found for the model based on stress concentration on the patch. Finally, a parametric study was performed considering the change in impactor speed and impactor material on impact damage. The effectiveness of finite element analysis of low velocity impact on aircraft composite structures is demonstrated.","PeriodicalId":356774,"journal":{"name":"Journal of Aeronautics and Aerospace Engineering","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115707049","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：