{"title":"Electrostatic Power from Negatively Charged Lunar Regolith","authors":"C. Sang H., Kim Hyun Jung, Moses Robert W.","doi":"10.36959/422/468","DOIUrl":"https://doi.org/10.36959/422/468","url":null,"abstract":"","PeriodicalId":130516,"journal":{"name":"Journal of Aerospace Engineering and Mechanics","volume":"56 22","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139131019","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":"Design of Hypervelocity Flow Generator (HFG) and Its Diagnostics","authors":"Song Kyo D, Choi Sang H","doi":"10.36959/422/466","DOIUrl":"https://doi.org/10.36959/422/466","url":null,"abstract":"","PeriodicalId":130516,"journal":{"name":"Journal of Aerospace Engineering and Mechanics","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127664546","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 study presents first a relatively lesser studied topic of the role played by surface-parallel restraints in determining the response of simply supported thick to thin doubly curved cross-ply panels of rectangular plan-form, modeled using a third order shear deformation theory, quantified by way of the difference between full and absent surface-parallel edge restraints. Mathematically speaking, this corresponds to the difference between complementary solutions to mixed boundary-value problems, resulting from two extreme sets of surface-parallel restraints. Of special interest is the three-way interaction of the membrane action due to curvature with the surface-parallel boundary constraint as well as the higher-order (resp. first-order) bending-stretching coupling producing beam-column/tie-bar type softening/hardening effects in thick (respectively thin) asymmetric cross-ply panels. Comparison with other popular shear deformation theories, such as the layer-wise constant shear-angle theory or zig-zag theory and first order shear deformation theory, also constitutes an important focus of this investigation. Results for cross-ply plates are regenerated in order to show the severity of the effect of curvature, especially in the thin shell regime.
{"title":"Effects of Surface-Parallel Edge Restraints and Inter-laminar Shear on the Responses of Doubly Curved General Cross-Ply Panels","authors":"Reaz Chaudhuri, Sinan Oktem","doi":"10.36959/422/463","DOIUrl":"https://doi.org/10.36959/422/463","url":null,"abstract":"This study presents first a relatively lesser studied topic of the role played by surface-parallel restraints in determining the response of simply supported thick to thin doubly curved cross-ply panels of rectangular plan-form, modeled using a third order shear deformation theory, quantified by way of the difference between full and absent surface-parallel edge restraints. Mathematically speaking, this corresponds to the difference between complementary solutions to mixed boundary-value problems, resulting from two extreme sets of surface-parallel restraints. Of special interest is the three-way interaction of the membrane action due to curvature with the surface-parallel boundary constraint as well as the higher-order (resp. first-order) bending-stretching coupling producing beam-column/tie-bar type softening/hardening effects in thick (respectively thin) asymmetric cross-ply panels. Comparison with other popular shear deformation theories, such as the layer-wise constant shear-angle theory or zig-zag theory and first order shear deformation theory, also constitutes an important focus of this investigation. Results for cross-ply plates are regenerated in order to show the severity of the effect of curvature, especially in the thin shell regime.","PeriodicalId":130516,"journal":{"name":"Journal of Aerospace Engineering and Mechanics","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126329672","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}
Zhang Minghui, Shi Haijuan, Wang Guangzhong, Yao Yan-an
The objective of this work is to investigate the effect of the bionic microstructure surface on DU21 aerofoil. The motivation behind this study is to investigate the effect of the bionic microstructure parameters including the location, interval between two microstructures, groove sizes of microstructure under different working conditions in order to improve the drag reduction characters. The numerical simulation is performed on the bionic microstructure model using the RNG k-ε model. It is found that: when the groove size is less than 0.15 mm, the drag can be reduced with any inflow speeds. When the groove size is 0.2 mm or 0.3 mm, the drag reduction effect can be achieved only when the inflow speed is relatively small. The resistance increases with any inflow speed when the groove size is up to 0.5 mm. The viscous resistance gradually increases, and the differential pressure resistance gradually decreases with the interval size increasing. There is a minimum resistance value when the groove depth h = 0.075 mm and the maximum drag reduction rate is up to 3.62%. Drag reduction mechanism of the microstructure was also studied. When the fluid passes through the microstructure, a stable reverse vortex flow is formed inside the groove, so that there is no direct contact between the fluid and the wall surface, thereby achieving a drag reduction effect. The vorticity values inside the grooves of the microstructure are smaller than that of the smooth airfoil and the turbulent kinetic energy and turbulent dissipation rate at the bottom of the groove are very small.
{"title":"Research on Drag Reduction Characteristics of Wind Turbine Airfoil Surface Microstructure","authors":"Zhang Minghui, Shi Haijuan, Wang Guangzhong, Yao Yan-an","doi":"10.36959/422/462","DOIUrl":"https://doi.org/10.36959/422/462","url":null,"abstract":"The objective of this work is to investigate the effect of the bionic microstructure surface on DU21 aerofoil. The motivation behind this study is to investigate the effect of the bionic microstructure parameters including the location, interval between two microstructures, groove sizes of microstructure under different working conditions in order to improve the drag reduction characters. The numerical simulation is performed on the bionic microstructure model using the RNG k-ε model. It is found that: when the groove size is less than 0.15 mm, the drag can be reduced with any inflow speeds. When the groove size is 0.2 mm or 0.3 mm, the drag reduction effect can be achieved only when the inflow speed is relatively small. The resistance increases with any inflow speed when the groove size is up to 0.5 mm. The viscous resistance gradually increases, and the differential pressure resistance gradually decreases with the interval size increasing. There is a minimum resistance value when the groove depth h = 0.075 mm and the maximum drag reduction rate is up to 3.62%. Drag reduction mechanism of the microstructure was also studied. When the fluid passes through the microstructure, a stable reverse vortex flow is formed inside the groove, so that there is no direct contact between the fluid and the wall surface, thereby achieving a drag reduction effect. The vorticity values inside the grooves of the microstructure are smaller than that of the smooth airfoil and the turbulent kinetic energy and turbulent dissipation rate at the bottom of the groove are very small.","PeriodicalId":130516,"journal":{"name":"Journal of Aerospace Engineering and Mechanics","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131869030","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}
Annotation: Technological methods for manufacturing cooling elements of modern rocket engines are considered. They are developed taking into account the possibility of reusable use, which reduces the cost of manufacturing similar products. It is shown that in this case, the thermal load on the walls of combustion chambers of liquid rocket engines increases significantly. This required the creation of new ways to protect the surface layer of the hot zone from the thermal effects of the flame in the fuel combustion zone. The possibilities of using plasma application of metal-ceramic heat-protective coatings for these purposes, which have good erosion resistance and high thermal resistance in conditions of intense exposure to high-temperature combustion products, are revealed. The analysis of the influence of the quality of the surface layer of coatings on the performance characteristics of the product is given. As a result, the need for local finishing of the applied coatings is justified, including in the transition areas of the combustion chambers and the jet nozzle, which have limited tool access to the processing zone. Here, the most effective method was the combined alignment of the micro profile with the imposition of an electric field. But for its implementation, a set of studies was needed to study the mechanism of removing the allowance, and to adjust the technological modes. The complex task of minimizing allowances for finishing combined processing was solved, which allowed to align the thickness of the heat-protective coating along the length of the fuel combustion path, including the cleaning sections, to increase the number of trouble-free engine starts by 1.5-2.0 times and ensure reusable use of products.
{"title":"Reducing the Aerodynamic Drag of the Mating Sections of the Combustion Chambers of Rocket Engines","authors":"Smolentsev Vladislav, Safonov Sergey, Panichev Evgeniy","doi":"10.36959/422/456","DOIUrl":"https://doi.org/10.36959/422/456","url":null,"abstract":"Annotation: Technological methods for manufacturing cooling elements of modern rocket engines are considered. They are developed taking into account the possibility of reusable use, which reduces the cost of manufacturing similar products. It is shown that in this case, the thermal load on the walls of combustion chambers of liquid rocket engines increases significantly. This required the creation of new ways to protect the surface layer of the hot zone from the thermal effects of the flame in the fuel combustion zone. The possibilities of using plasma application of metal-ceramic heat-protective coatings for these purposes, which have good erosion resistance and high thermal resistance in conditions of intense exposure to high-temperature combustion products, are revealed. The analysis of the influence of the quality of the surface layer of coatings on the performance characteristics of the product is given. As a result, the need for local finishing of the applied coatings is justified, including in the transition areas of the combustion chambers and the jet nozzle, which have limited tool access to the processing zone. Here, the most effective method was the combined alignment of the micro profile with the imposition of an electric field. But for its implementation, a set of studies was needed to study the mechanism of removing the allowance, and to adjust the technological modes. The complex task of minimizing allowances for finishing combined processing was solved, which allowed to align the thickness of the heat-protective coating along the length of the fuel combustion path, including the cleaning sections, to increase the number of trouble-free engine starts by 1.5-2.0 times and ensure reusable use of products.","PeriodicalId":130516,"journal":{"name":"Journal of Aerospace Engineering and Mechanics","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116269347","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}
Currently, there are several coatings used to protect various defense and space crafts, however, they fail to perform in extreme environments due to limitations in that they are designed and in operation for specific environments. While existing materials like aluminum alloys, steels, magnesium alloys and titanium alloys [1] suffer from surface oxidation, mismatch of thermal expansion coefficients, corrosions and poor mechanical strength, new research verified through the US Army’s Future Vertical Lift initiative shows that two carbon-based nanomaterials two-dimensional fluorinated graphene oxide (FGO) and nanocrystalline diamond (NCD) are amongst the most promising electro-optic materials to be applied to air and space crafts.
{"title":"Performance and Scalability Make Advanced Carbon Materials Optimal for Air and Space Crafts","authors":"Khan M. Adam, K. Kiran Kumar","doi":"10.36959/422/457","DOIUrl":"https://doi.org/10.36959/422/457","url":null,"abstract":"Currently, there are several coatings used to protect various defense and space crafts, however, they fail to perform in extreme environments due to limitations in that they are designed and in operation for specific environments. While existing materials like aluminum alloys, steels, magnesium alloys and titanium alloys [1] suffer from surface oxidation, mismatch of thermal expansion coefficients, corrosions and poor mechanical strength, new research verified through the US Army’s Future Vertical Lift initiative shows that two carbon-based nanomaterials two-dimensional fluorinated graphene oxide (FGO) and nanocrystalline diamond (NCD) are amongst the most promising electro-optic materials to be applied to air and space crafts.","PeriodicalId":130516,"journal":{"name":"Journal of Aerospace Engineering and Mechanics","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123533435","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}
Pinnamaneni Sai Krishna, Patabendige Hasintha Hiran Amaranayaka Kariyakarawana, Beyle Andrey
The aim of the study is to perform FE Analysis using ANSYS for the Honeycomb sandwich structures with varying skin thickness ranging from 0.5 to 2 mm and edges of the honeycombs are converted into curve shapes to avoid any stress concentration at the intersection. The study of the natural frequencies of the structure is also carried out. The core structure is made up of Aluminum alloy and the skin or face sheet is made up of carbon fiber and the properties are been evaluated from ANSYS Engineering Data Source. The core has been modeled with a radius of curvature of 1.5 mm and different from conventional honeycomb structure with sharp edges, an increase in skin thickness has improved the load bearing capacity of the specimen.
{"title":"Modelling of Honeycomb Sandwich Structure with Curved Edges and Performing Analysis Using Finite Element Method","authors":"Pinnamaneni Sai Krishna, Patabendige Hasintha Hiran Amaranayaka Kariyakarawana, Beyle Andrey","doi":"10.36959/422/455","DOIUrl":"https://doi.org/10.36959/422/455","url":null,"abstract":"The aim of the study is to perform FE Analysis using ANSYS for the Honeycomb sandwich structures with varying skin thickness ranging from 0.5 to 2 mm and edges of the honeycombs are converted into curve shapes to avoid any stress concentration at the intersection. The study of the natural frequencies of the structure is also carried out. The core structure is made up of Aluminum alloy and the skin or face sheet is made up of carbon fiber and the properties are been evaluated from ANSYS Engineering Data Source. The core has been modeled with a radius of curvature of 1.5 mm and different from conventional honeycomb structure with sharp edges, an increase in skin thickness has improved the load bearing capacity of the specimen.","PeriodicalId":130516,"journal":{"name":"Journal of Aerospace Engineering and Mechanics","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126009165","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}
Zafarghandi Fatemeh Mahdavi, Soltani Mohammad Reza
A series of experiments was carried out to investigate the aerodynamic characteristics of a cranked-delta wing model. It has been noted by various researches that in the vicinity of the take-off angles of attack, an instability in the longitudinal stability of aircraft equipped with cranked delta wings occurs where its origin is not well understood yet. To further study this phenomenon, a semi-span cranked delta wing model was designed and built. Surface pressure data for various angles of attack at low subsonic speeds, to better simulate take-off and landing conditions, were measured. The only test limitations of concern were inaccessibility to an accurate balance to measure forces and moments and to correlate them with the surface pressure data. However, analysis of the surface reassure data showed formations of two distinct strong vortices over the wing surface with strong suction peaks at their cores. The interaction between the two vortices increased with angle-of-attack, and as a result, the outer vortex moved inward while the inner vortex moved outward. At a certain angle-of-attack, these vortices merge with each other and at higher angles of attack the vortex breakdown moved onto the wing surface and as a result, the suction peak collapsed and spread in the spanwise direction. Surface pressure data clearly shows that the angle of attack where the vortex burst moves onto the wing surface correlates well with the previous studies regarding the mentioned longitudinal instability. These findings could help designers to optimize the crank angles to avoid such an undesired phenomenon.
{"title":"An Experimental Investigation of the Vortex Merging over a Cranked-Delta Wing at Subsonic Speed","authors":"Zafarghandi Fatemeh Mahdavi, Soltani Mohammad Reza","doi":"10.36959/422/453","DOIUrl":"https://doi.org/10.36959/422/453","url":null,"abstract":"A series of experiments was carried out to investigate the aerodynamic characteristics of a cranked-delta wing model. It has been noted by various researches that in the vicinity of the take-off angles of attack, an instability in the longitudinal stability of aircraft equipped with cranked delta wings occurs where its origin is not well understood yet. To further study this phenomenon, a semi-span cranked delta wing model was designed and built. Surface pressure data for various angles of attack at low subsonic speeds, to better simulate take-off and landing conditions, were measured. The only test limitations of concern were inaccessibility to an accurate balance to measure forces and moments and to correlate them with the surface pressure data. However, analysis of the surface reassure data showed formations of two distinct strong vortices over the wing surface with strong suction peaks at their cores. The interaction between the two vortices increased with angle-of-attack, and as a result, the outer vortex moved inward while the inner vortex moved outward. At a certain angle-of-attack, these vortices merge with each other and at higher angles of attack the vortex breakdown moved onto the wing surface and as a result, the suction peak collapsed and spread in the spanwise direction. Surface pressure data clearly shows that the angle of attack where the vortex burst moves onto the wing surface correlates well with the previous studies regarding the mentioned longitudinal instability. These findings could help designers to optimize the crank angles to avoid such an undesired phenomenon.","PeriodicalId":130516,"journal":{"name":"Journal of Aerospace Engineering and Mechanics","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133423637","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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