Pub Date : 2024-09-19DOI: 10.1177/09544100241283329
Nikolay Turbin, Kirill Shelkov, Yuri Ivanov, Nikolay Chashin
In the current research, a method for estimation of the durability of a structure based on an integrated calculation of static and fatigue strength according to the criterion of allowable strain is presented. The proposed technique is demonstrated for the upper stringer panel of the wing design. In the course of calculations, several combinations of design service objectives, levels of allowable strains, and levels of cyclic stresses were considered. As a result, the relative values of stiffness degradation and the required safety ratios of static strength were obtained.
{"title":"Fatigue life analysis of a composite materials structure using allowable strain criteria","authors":"Nikolay Turbin, Kirill Shelkov, Yuri Ivanov, Nikolay Chashin","doi":"10.1177/09544100241283329","DOIUrl":"https://doi.org/10.1177/09544100241283329","url":null,"abstract":"In the current research, a method for estimation of the durability of a structure based on an integrated calculation of static and fatigue strength according to the criterion of allowable strain is presented. The proposed technique is demonstrated for the upper stringer panel of the wing design. In the course of calculations, several combinations of design service objectives, levels of allowable strains, and levels of cyclic stresses were considered. As a result, the relative values of stiffness degradation and the required safety ratios of static strength were obtained.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"42 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-19DOI: 10.1177/09544100241283422
Sundharesan R, Sai Prasanna Kumar JV
Composite pressure vessels are used in aerospace engineering for storing fluids such as propellants, nitrogen, and oxygen. They are also used in life-support systems, High-performance pressure suits for astronauts, Helium Tanks for Balloons and Airships. Among many types of composites, Carbon fiber composites uses have been increasing due to its high strength to weight ratio, high thermal expansion, corrosion, fatigue and impact resistance and design flexibility. In order to improve the volume of the pressure vessel, the liner-less concept is tried. This increased volume efficiency is crucial in aerospace applications where space is at a premium and maximizing storage capacity within limited dimensions is important. Not only the volume efficiency, but also the Reduced Permeability Concerns, Enhanced Durability and Longevity, better thermal continuity and simplified manufacturing process make this research significant in the area of pressure vessel. This research paper deals with the fabrication and development of a cylinder without a lining. The test sample was subjected to several tests: tensile test, impact, shear test (3P Bending), leak test and Pressure test. The test sample was capable of withstanding 20 Bars without failure. The numerical results were also performed and compared with the experimental results. The difference was only 3%. Unsymmetrical dimethyl hydrazine (UDMH) AND red-fuming nitric acid can both be stored in this cylinder (RFNA). Unlike traditional composite overwrapped pressure vessels, the liner-less composite tanks rely completely on the composite shell to act as a permeation barrier as well as handling all pressure and environmental loads. The absence of a liner eliminates the potential for delamination or failure at the interface between the liner and the composite material.
{"title":"Feasibility study of carbon-fiber reinforced polymer linerless pressure vessel tank","authors":"Sundharesan R, Sai Prasanna Kumar JV","doi":"10.1177/09544100241283422","DOIUrl":"https://doi.org/10.1177/09544100241283422","url":null,"abstract":"Composite pressure vessels are used in aerospace engineering for storing fluids such as propellants, nitrogen, and oxygen. They are also used in life-support systems, High-performance pressure suits for astronauts, Helium Tanks for Balloons and Airships. Among many types of composites, Carbon fiber composites uses have been increasing due to its high strength to weight ratio, high thermal expansion, corrosion, fatigue and impact resistance and design flexibility. In order to improve the volume of the pressure vessel, the liner-less concept is tried. This increased volume efficiency is crucial in aerospace applications where space is at a premium and maximizing storage capacity within limited dimensions is important. Not only the volume efficiency, but also the Reduced Permeability Concerns, Enhanced Durability and Longevity, better thermal continuity and simplified manufacturing process make this research significant in the area of pressure vessel. This research paper deals with the fabrication and development of a cylinder without a lining. The test sample was subjected to several tests: tensile test, impact, shear test (3P Bending), leak test and Pressure test. The test sample was capable of withstanding 20 Bars without failure. The numerical results were also performed and compared with the experimental results. The difference was only 3%. Unsymmetrical dimethyl hydrazine (UDMH) AND red-fuming nitric acid can both be stored in this cylinder (RFNA). Unlike traditional composite overwrapped pressure vessels, the liner-less composite tanks rely completely on the composite shell to act as a permeation barrier as well as handling all pressure and environmental loads. The absence of a liner eliminates the potential for delamination or failure at the interface between the liner and the composite material.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"9 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-17DOI: 10.1177/09544100241283705
Shijie Huang, Jing Cai, Dingqiang Dai
This paper aims to optimize the testability analysis method of aero-engines by presenting a testability modeling and an improved correlation matrix method. Because of strong coupling in aero-engines, the traditional testabilitsy modeling method based on graph theory is difficult to accurately express the relationship between faults and test points. Simulation technology can simulate actual work process of system. So this paper launches the research based on simulation model. Firstly, the gas path model is established according to the thermodynamic principle of aero-engines and accuracy of the model is verified. Secondly, common faults of gas path are selected. Affected parameters are obtained after injecting faults into the model, so as to obtain the relationship between faults and test points, that is, the correlation matrix. Then, after going through masses of simulations, it is found that the relationship between faults and test points can be divided into three categories: positive correlation, negative correlation and no correlation. The correlation matrix can be improved by diversifying its elements. During simulation, accuracy of the sensors are not considered. The correlation matrix is optimized with the accuracy of sensors in the gas path as a constraint, so that it is more in line with engineering practice. Finally, four testability characteristics and two testability metrics are defined, and the correlation matrix before and after improvement are analyzed and compared. It is found that the improved correlation matrix can isolate more faults on the premise of reducing test points, which proves the effectiveness of the proposed method.
{"title":"Testability modeling of aeroengine and analysis optimization method based on improved correlation matrix","authors":"Shijie Huang, Jing Cai, Dingqiang Dai","doi":"10.1177/09544100241283705","DOIUrl":"https://doi.org/10.1177/09544100241283705","url":null,"abstract":"This paper aims to optimize the testability analysis method of aero-engines by presenting a testability modeling and an improved correlation matrix method. Because of strong coupling in aero-engines, the traditional testabilitsy modeling method based on graph theory is difficult to accurately express the relationship between faults and test points. Simulation technology can simulate actual work process of system. So this paper launches the research based on simulation model. Firstly, the gas path model is established according to the thermodynamic principle of aero-engines and accuracy of the model is verified. Secondly, common faults of gas path are selected. Affected parameters are obtained after injecting faults into the model, so as to obtain the relationship between faults and test points, that is, the correlation matrix. Then, after going through masses of simulations, it is found that the relationship between faults and test points can be divided into three categories: positive correlation, negative correlation and no correlation. The correlation matrix can be improved by diversifying its elements. During simulation, accuracy of the sensors are not considered. The correlation matrix is optimized with the accuracy of sensors in the gas path as a constraint, so that it is more in line with engineering practice. Finally, four testability characteristics and two testability metrics are defined, and the correlation matrix before and after improvement are analyzed and compared. It is found that the improved correlation matrix can isolate more faults on the premise of reducing test points, which proves the effectiveness of the proposed method.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"15 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-17DOI: 10.1177/09544100241274870
Ruichen Ming, Xiaoxiong Liu, Yu Li, WeiGuo Zhang
The adaptive backstepping method has strong performance in handling control problems with disturbances in previous research. However, it exhibits limitations when applied to time-varying disturbances. This paper proposes an improved adaptive backstepping method based on Discrete Fourier Transform (DFT). By estimating the frequency spectrum of the disturbance and indirectly obtaining its time-domain estimate, the proposed method effectively overcomes the shortcomings of traditional adaptive backstepping. To address the issue of frequency leakage caused by discontinuities in window data, the idea of DFT is improved by using STFT with the addition of the window function and window-shifting operation. Additionally, a projection operator and adaptive reduction of the control objective are employed to mitigate the effects of actuator saturation. Finally, in simulations involving an aircraft subjected to gusts and turbulence, the proposed method is compared with traditional adaptive backstepping and radial basis function (RBF) neural network control methods. Simulation results demonstrate that the proposed method outperforms the others in these experimental scenarios.
{"title":"Research on a backstepping flight control method improved by STFT in atmospheric disturbance applications","authors":"Ruichen Ming, Xiaoxiong Liu, Yu Li, WeiGuo Zhang","doi":"10.1177/09544100241274870","DOIUrl":"https://doi.org/10.1177/09544100241274870","url":null,"abstract":"The adaptive backstepping method has strong performance in handling control problems with disturbances in previous research. However, it exhibits limitations when applied to time-varying disturbances. This paper proposes an improved adaptive backstepping method based on Discrete Fourier Transform (DFT). By estimating the frequency spectrum of the disturbance and indirectly obtaining its time-domain estimate, the proposed method effectively overcomes the shortcomings of traditional adaptive backstepping. To address the issue of frequency leakage caused by discontinuities in window data, the idea of DFT is improved by using STFT with the addition of the window function and window-shifting operation. Additionally, a projection operator and adaptive reduction of the control objective are employed to mitigate the effects of actuator saturation. Finally, in simulations involving an aircraft subjected to gusts and turbulence, the proposed method is compared with traditional adaptive backstepping and radial basis function (RBF) neural network control methods. Simulation results demonstrate that the proposed method outperforms the others in these experimental scenarios.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"47 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-14DOI: 10.1177/09544100241282718
Neale A Watson, Ieuan Owen, Mark D White
Turbulent ship airwakes can present a major challenge for a pilot landing a helicopter to the ship. A recent study has proposed modifications to the hangar of a simple ship, the SFS2, to improve the air flow over the deck. To assess the effect of the proposed hangar modification on the helicopter and pilot, the unsteady air flow over the modified ship has been computed using time-accurate CFD, and then integrated with a full-motion flight simulator for a pilot to conduct deck landings to the original and modified ship geometries in wind speeds from 30 kt to 50 kt. The effectiveness of the proposed modification was assessed through pilot workload ratings for the landing task, and by recording pilot control inputs and helicopter states. The study has shown that there are some benefits from the hangar modifications. In the headwind the helicopter was deemed to be at the safe limit at 50 kt when operating to the original SFS2, while the limit was not reached in the 50 kt wind for the modified ship. In an oblique wind, the safe wind speed limit was found to be 40 kt for the original ship and 50 kt for the modified version. Although the improvements are not substantial, they do represent a positive outcome.
{"title":"Evaluating the effect of frigate hangar shape modifications on helicopter recovery using piloted flight simulation","authors":"Neale A Watson, Ieuan Owen, Mark D White","doi":"10.1177/09544100241282718","DOIUrl":"https://doi.org/10.1177/09544100241282718","url":null,"abstract":"Turbulent ship airwakes can present a major challenge for a pilot landing a helicopter to the ship. A recent study has proposed modifications to the hangar of a simple ship, the SFS2, to improve the air flow over the deck. To assess the effect of the proposed hangar modification on the helicopter and pilot, the unsteady air flow over the modified ship has been computed using time-accurate CFD, and then integrated with a full-motion flight simulator for a pilot to conduct deck landings to the original and modified ship geometries in wind speeds from 30 kt to 50 kt. The effectiveness of the proposed modification was assessed through pilot workload ratings for the landing task, and by recording pilot control inputs and helicopter states. The study has shown that there are some benefits from the hangar modifications. In the headwind the helicopter was deemed to be at the safe limit at 50 kt when operating to the original SFS2, while the limit was not reached in the 50 kt wind for the modified ship. In an oblique wind, the safe wind speed limit was found to be 40 kt for the original ship and 50 kt for the modified version. Although the improvements are not substantial, they do represent a positive outcome.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"28 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-14DOI: 10.1177/09544100241283365
Mohd I Ansari, Syed F Anwer, Mohammed H Siddique, Tabish Alam
A numerical investigation is conducted on the two-dimensional corrugated wing section of the dragonfly Aeshna cyanea in forward flapping flight mode. The analysis aimed to determine the impact of various kinematic parameters on the aerodynamic performance and to identify the optimal kinematic conditions for achieving maximum mean lift ([Formula: see text]) and minimum mean drag coefficient ([Formula: see text]). In forward flapping flight mode, the insect moves forward by flapping its wings, and the forward velocity is not zero. The study used the QUICK (Quadratic Upstream Interpolation for Convective Kinetics) scheme for spatial discretization of convective terms and first-order accurate implicit for temporal discretization. The dynamic mesh method following the Arbitrary Lagrangian Eulerian (ALE) formulation is used to track the moving interface of rigid wing section in the fluid domain. It has been observed that the maximum of lift and drag occur during the downstroke of flight. The vortical structures are larger in size at the leading and trailing edges when the peak of lift occurs. The larger leading-edge vortex on the lower surface of the airfoil creates a low-pressure region, thus increasing the peak drag. The kinematic parameters of best performance varied depending on the performance parameter being considered. The Pareto optimal front (POF) is obtained using multi-objective optimization method using surrogate models, which is a set of various design points obtained considering the maximum mean lift and lowest mean drag as objectives. From the POF, one can obtain the corresponding drag and optimum kinematic parameters for a particular lift, and vice versa, for an optimum design.
{"title":"Optimization of kinematic parameters of dragonfly wing section in forward flapping flight","authors":"Mohd I Ansari, Syed F Anwer, Mohammed H Siddique, Tabish Alam","doi":"10.1177/09544100241283365","DOIUrl":"https://doi.org/10.1177/09544100241283365","url":null,"abstract":"A numerical investigation is conducted on the two-dimensional corrugated wing section of the dragonfly Aeshna cyanea in forward flapping flight mode. The analysis aimed to determine the impact of various kinematic parameters on the aerodynamic performance and to identify the optimal kinematic conditions for achieving maximum mean lift ([Formula: see text]) and minimum mean drag coefficient ([Formula: see text]). In forward flapping flight mode, the insect moves forward by flapping its wings, and the forward velocity is not zero. The study used the QUICK (Quadratic Upstream Interpolation for Convective Kinetics) scheme for spatial discretization of convective terms and first-order accurate implicit for temporal discretization. The dynamic mesh method following the Arbitrary Lagrangian Eulerian (ALE) formulation is used to track the moving interface of rigid wing section in the fluid domain. It has been observed that the maximum of lift and drag occur during the downstroke of flight. The vortical structures are larger in size at the leading and trailing edges when the peak of lift occurs. The larger leading-edge vortex on the lower surface of the airfoil creates a low-pressure region, thus increasing the peak drag. The kinematic parameters of best performance varied depending on the performance parameter being considered. The Pareto optimal front (POF) is obtained using multi-objective optimization method using surrogate models, which is a set of various design points obtained considering the maximum mean lift and lowest mean drag as objectives. From the POF, one can obtain the corresponding drag and optimum kinematic parameters for a particular lift, and vice versa, for an optimum design.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"16 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-14DOI: 10.1177/09544100241277236
Axing Xi, Yuanli Cai
To reduce computational loads and save communication resources of multi-missile systems, event-triggered-based distributed differential game guidance laws for the nonlinear cooperative multi-missile system are investigated. First, the cooperative multi-missile interception problem is converted into multi-player zero-sum differential games, where all missiles minimize the cost function while the target maximizes the cost function. Second, event-triggered conditions are designed, for implementing the proposed guidance laws, Adaptive Dynamic Programming technique is adopted to approximate the couple event-triggered Hamilton-Jacobi–Isaacs equation, and adaptive weight-tuning laws are proposed. Furthermore, the proposed guidance laws can guarantee the stability of the nonlinear multi-missile system, which is proved by Lyapunov theory. The estimated weights of neural network and consensus tracking errors are ensured to be Uniformly Ultimately Bounded. Besides, a minimal inter-sample time is established to avoid the Zeno behavior. Finally, experiments show that the number of controller updates can be reduced to 65.36% by the proposed algorithm.
{"title":"Event-triggered-based distributed differential game guidance laws","authors":"Axing Xi, Yuanli Cai","doi":"10.1177/09544100241277236","DOIUrl":"https://doi.org/10.1177/09544100241277236","url":null,"abstract":"To reduce computational loads and save communication resources of multi-missile systems, event-triggered-based distributed differential game guidance laws for the nonlinear cooperative multi-missile system are investigated. First, the cooperative multi-missile interception problem is converted into multi-player zero-sum differential games, where all missiles minimize the cost function while the target maximizes the cost function. Second, event-triggered conditions are designed, for implementing the proposed guidance laws, Adaptive Dynamic Programming technique is adopted to approximate the couple event-triggered Hamilton-Jacobi–Isaacs equation, and adaptive weight-tuning laws are proposed. Furthermore, the proposed guidance laws can guarantee the stability of the nonlinear multi-missile system, which is proved by Lyapunov theory. The estimated weights of neural network and consensus tracking errors are ensured to be Uniformly Ultimately Bounded. Besides, a minimal inter-sample time is established to avoid the Zeno behavior. Finally, experiments show that the number of controller updates can be reduced to 65.36% by the proposed algorithm.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"3 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10DOI: 10.1177/09544100241278997
Saeed Hosseini, Mohammad Ali Vaziry-Zanjany, Hamid Reza Ovesy
In this research, a method is developed to optimize the truss-braced wing aircraft configuration in a multidisciplinary design framework. Physics-based high-fidelity methods, that can capture the nature of the configuration changes, are employed for the disciplines where the existing classical methods are not reliable. High-fidelity geometry modeling, structure loading, structure optimization, and aeroelastic sizing methods are integrated into the aircraft multidisciplinary design and optimization. The developed algorithm is applied for the multi-objective optimization of a regional jet aircraft to minimize the cost and weight. The results demonstrate that the cost-optimum solution converges to a higher aspect ratio wing equipped with a higher bypass ratio engine, and a 7.94% reduction in the direct operating cost can be achieved. On the other hand, the weight-optimum wing planform tends to a slightly lower aspect ratio wing with a lower bypass ratio engine, while a 6.18% reduction in take-off weight is achieved. In addition to that, the findings of this study highlight the considerable effect that the engine technology has on the optimum layout, which suggests that the engine technology and its performance should also be a part of the design optimization process. The developed modular framework offers further optimization potential for the truss-braced wing aircraft, as more detailed models can be integrated.
{"title":"Multidisciplinary optimization methodology for truss-braced wing aircraft using high-fidelity structure sizing","authors":"Saeed Hosseini, Mohammad Ali Vaziry-Zanjany, Hamid Reza Ovesy","doi":"10.1177/09544100241278997","DOIUrl":"https://doi.org/10.1177/09544100241278997","url":null,"abstract":"In this research, a method is developed to optimize the truss-braced wing aircraft configuration in a multidisciplinary design framework. Physics-based high-fidelity methods, that can capture the nature of the configuration changes, are employed for the disciplines where the existing classical methods are not reliable. High-fidelity geometry modeling, structure loading, structure optimization, and aeroelastic sizing methods are integrated into the aircraft multidisciplinary design and optimization. The developed algorithm is applied for the multi-objective optimization of a regional jet aircraft to minimize the cost and weight. The results demonstrate that the cost-optimum solution converges to a higher aspect ratio wing equipped with a higher bypass ratio engine, and a 7.94% reduction in the direct operating cost can be achieved. On the other hand, the weight-optimum wing planform tends to a slightly lower aspect ratio wing with a lower bypass ratio engine, while a 6.18% reduction in take-off weight is achieved. In addition to that, the findings of this study highlight the considerable effect that the engine technology has on the optimum layout, which suggests that the engine technology and its performance should also be a part of the design optimization process. The developed modular framework offers further optimization potential for the truss-braced wing aircraft, as more detailed models can be integrated.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"13 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Existing mathematical models for deflector jet hydraulic amplifiers cannot accurately describe the influence of the deflector motion on the receiver jet, which results in calculation differences for the receiver pressure. To deeply investigate this problem, the momentum transfer model considering secondary jet velocity distribution was used to develop an improved model that is more aligned with the actual state of the flow field. In this model, the receiver jet velocity is calculated, for the first time, with a maximum error of 18% when compared with existing models. To verify the improved model, the recovery pressures in the receivers were verified by numerical simulations and experiments. The verification results show that the model can accurately predict the recovery pressures in the receivers within an 8.1% maximum error. This model fills the gaps in the theoretical research and lays a foundation for the structural design of deflector jet pressure servo valves.
{"title":"Mathematical modeling and experimental investigation of pressure characteristics inside the pilot stage of the deflector jet servo valve considering secondary jet velocity distribution","authors":"Shenghong Ge, Hanhao Yang, Wenhao Cheng, Yuchuan Zhu","doi":"10.1177/09544100241277234","DOIUrl":"https://doi.org/10.1177/09544100241277234","url":null,"abstract":"Existing mathematical models for deflector jet hydraulic amplifiers cannot accurately describe the influence of the deflector motion on the receiver jet, which results in calculation differences for the receiver pressure. To deeply investigate this problem, the momentum transfer model considering secondary jet velocity distribution was used to develop an improved model that is more aligned with the actual state of the flow field. In this model, the receiver jet velocity is calculated, for the first time, with a maximum error of 18% when compared with existing models. To verify the improved model, the recovery pressures in the receivers were verified by numerical simulations and experiments. The verification results show that the model can accurately predict the recovery pressures in the receivers within an 8.1% maximum error. This model fills the gaps in the theoretical research and lays a foundation for the structural design of deflector jet pressure servo valves.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"24 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-30DOI: 10.1177/09544100241272763
Joseph Davis, Minje Park, Isaac Shapiro, Mark Costello
Traditional air mobility capability development consists of defining a set of requirements and subsequently designing an aircraft that satisfies these requirements. Once designed, the overall structure or topology of the aircraft is fixed. That is, the aircraft has certain fixed physical dimensions, number and sizes of rotors, engines, etc. The topology cannot be changed to accomplish missions outside of its original design envelope, and if designed for a robust mission spectrum, the aircraft may be inefficient during routine missions that do not require peak performance. The work reported here takes a different approach where a core set of components (fuselage, rotor, power plant, etc) defines the fundamental modules of the air mobility system. The modules were developed using mature and readily available technologies and designed to be quickly connected to other modules to assemble different aircraft configurations with widely varying performance characteristics. The aircraft can be reconfigured between missions to best satisfy mission requirements. Thus, the envelope of achievable performance characteristics is significantly expanded compared to a single aircraft. This concept is explored for autonomous air cargo delivery missions targeted for nominal payloads and ranges around 500 pounds and 500 nautical miles with maximum payloads up to 3500 pounds across shorter distances. Results indicate that for mission spectrums with large differences between nominal and maximum payloads and skewed towards smaller payloads, the operational cost per lb-km is significantly reduced using a modular and reconfigurable air mobility system since cargo delivery requirements can be better matched to an air vehicle system.
{"title":"Modular reconfigurable rotorcraft for autonomous cargo delivery","authors":"Joseph Davis, Minje Park, Isaac Shapiro, Mark Costello","doi":"10.1177/09544100241272763","DOIUrl":"https://doi.org/10.1177/09544100241272763","url":null,"abstract":"Traditional air mobility capability development consists of defining a set of requirements and subsequently designing an aircraft that satisfies these requirements. Once designed, the overall structure or topology of the aircraft is fixed. That is, the aircraft has certain fixed physical dimensions, number and sizes of rotors, engines, etc. The topology cannot be changed to accomplish missions outside of its original design envelope, and if designed for a robust mission spectrum, the aircraft may be inefficient during routine missions that do not require peak performance. The work reported here takes a different approach where a core set of components (fuselage, rotor, power plant, etc) defines the fundamental modules of the air mobility system. The modules were developed using mature and readily available technologies and designed to be quickly connected to other modules to assemble different aircraft configurations with widely varying performance characteristics. The aircraft can be reconfigured between missions to best satisfy mission requirements. Thus, the envelope of achievable performance characteristics is significantly expanded compared to a single aircraft. This concept is explored for autonomous air cargo delivery missions targeted for nominal payloads and ranges around 500 pounds and 500 nautical miles with maximum payloads up to 3500 pounds across shorter distances. Results indicate that for mission spectrums with large differences between nominal and maximum payloads and skewed towards smaller payloads, the operational cost per lb-km is significantly reduced using a modular and reconfigurable air mobility system since cargo delivery requirements can be better matched to an air vehicle system.","PeriodicalId":54566,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part G-Journal of Aerospace Engineering","volume":"44 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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