Pub Date : 2021-05-10DOI: 10.4050/f-0077-2021-16838
Johannes Hofmann, M. Mindt, Felix Weiss
A new comprehensive aeromechanics code for rotary wing aircraft is being developed at the German Aerospace Center. It follows a new and very general approach in modeling all physical subsystems and numerical methods in one common interface description. The structure of the code makes no assumptions about the system to be modeled and builds the global system strictly from the logical connections of the sub-models. It relies heavily on modern language features and programming techniques like algorithmic differentiation. This paper describes the novel approach and currently implemented features. While verification and validation are a part of the paper it is not the sole purpose. The calculations serve rather as a means of verifying the general approach and its fitness for the long-term vision of the code. The description of the architectural concept is the main purpose of this paper. The description and evaluation is being underlined with a set of verification and preliminary validation cases.
{"title":"A New Approach to Comprehensive Rotorcraft Aeromechanics Simulation","authors":"Johannes Hofmann, M. Mindt, Felix Weiss","doi":"10.4050/f-0077-2021-16838","DOIUrl":"https://doi.org/10.4050/f-0077-2021-16838","url":null,"abstract":"\u0000 A new comprehensive aeromechanics code for rotary wing aircraft is being developed at the German Aerospace Center. It follows a new and very general approach in modeling all physical subsystems and numerical methods in one common interface description. The structure of the code makes no assumptions about the system to be modeled and builds the global system strictly from the logical connections of the sub-models. It relies heavily on modern language features and programming techniques like algorithmic differentiation. This paper describes the novel approach and currently implemented features. While verification and validation are a part of the paper it is not the sole purpose. The calculations serve rather as a means of verifying the general approach and its fitness for the long-term vision of the code. The description of the architectural concept is the main purpose of this paper. The description and evaluation is being underlined with a set of verification and preliminary validation cases.\u0000","PeriodicalId":273020,"journal":{"name":"Proceedings of the Vertical Flight Society 77th Annual Forum","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125728770","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 : 2021-05-10DOI: 10.4050/f-0077-2021-16746
Z. Szoboszlay, Martine Godfroy-Cooper, J. Miller
The Degraded Visual Environment Mitigation (DVE-M) program was initiated to develop and evaluate numerous technologies that would enable rotorcraft to intentionally operate in poor visibility conditions. The goal was to provide recommendations to the Future Vertical Lift program and to various upgrade programs of the existing fleet of military rotorcraft. The DVE-M program was implemented by the U.S. Army Combat Capabilities Development Command Aviation and Missile Center (DEVCOM AvMC). Technologies developed and evaluated fell into one of three categories: 1) sensors and sensor fusion, 2) pilot cueing, 3) flight control and guidance. These technologies were integrated to work together to enable the pilot to operate in DVE. This paper focuses on the design of the cueing system only. It discusses reasons for the design choices and lessons learned. This paper also provides an overview of the flight demonstrations and simulations conducted for background.
{"title":"The Design of Pilot Cueing for the Degraded Visual Environment Mitigation (DVE-M) System for Rotorcraft","authors":"Z. Szoboszlay, Martine Godfroy-Cooper, J. Miller","doi":"10.4050/f-0077-2021-16746","DOIUrl":"https://doi.org/10.4050/f-0077-2021-16746","url":null,"abstract":"\u0000 The Degraded Visual Environment Mitigation (DVE-M) program was initiated to develop and evaluate numerous technologies that would enable rotorcraft to intentionally operate in poor visibility conditions. The goal was to provide recommendations to the Future Vertical Lift program and to various upgrade programs of the existing fleet of military rotorcraft. The DVE-M program was implemented by the U.S. Army Combat Capabilities Development Command Aviation and Missile Center (DEVCOM AvMC). Technologies developed and evaluated fell into one of three categories: 1) sensors and sensor fusion, 2) pilot cueing, 3) flight control and guidance. These technologies were integrated to work together to enable the pilot to operate in DVE. This paper focuses on the design of the cueing system only. It discusses reasons for the design choices and lessons learned. This paper also provides an overview of the flight demonstrations and simulations conducted for background.\u0000","PeriodicalId":273020,"journal":{"name":"Proceedings of the Vertical Flight Society 77th Annual Forum","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125356567","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 : 2021-05-10DOI: 10.4050/f-0077-2021-16903
Chen He, E. Bae, Tzikang Chen, Dooyong Lee, M. Haile
Rotorcraft experience vibratory loads due to the constantly varying airloads under all flight conditions. Maximizing the fatigue life of their structural components is a vital factor for sustained operations with low-maintenance. Most existing fatigue analysis methods are empirical and, hence, are limited for use in investigating the effects of maneuvering f light as well as for exploring modern control methods (e.g., on-blade controls (OBC)) for alleviating fatigue. This paper discusses comprehensive simulation-based rotorcraft loads/stress analysis and fatigue alleviation control methods toward the goal of minimum maintenance for future vertical lift. The paper covers several aspects, including comprehensive modeling for loads prediction, blade stress analysis with the applied loads, fatigue estimation, and loads/stress reduction control formulation. The paper also presents simulation results that demonstrate the successful reduction of vibratory loads/stress using modern on-blade active control methods.
{"title":"Comprehensive Simulation Based Rotorcraft Loads/Fatigue Analysis and Alleviation Method","authors":"Chen He, E. Bae, Tzikang Chen, Dooyong Lee, M. Haile","doi":"10.4050/f-0077-2021-16903","DOIUrl":"https://doi.org/10.4050/f-0077-2021-16903","url":null,"abstract":"\u0000 Rotorcraft experience vibratory loads due to the constantly varying airloads under all flight conditions. Maximizing the fatigue life of their structural components is a vital factor for sustained operations with low-maintenance. Most existing fatigue analysis methods are empirical and, hence, are limited for use in investigating the effects of maneuvering f light as well as for exploring modern control methods (e.g., on-blade controls (OBC)) for alleviating fatigue. This paper discusses comprehensive simulation-based rotorcraft loads/stress analysis and fatigue alleviation control methods toward the goal of minimum maintenance for future vertical lift. The paper covers several aspects, including comprehensive modeling for loads prediction, blade stress analysis with the applied loads, fatigue estimation, and loads/stress reduction control formulation. The paper also presents simulation results that demonstrate the successful reduction of vibratory loads/stress using modern on-blade active control methods.\u0000","PeriodicalId":273020,"journal":{"name":"Proceedings of the Vertical Flight Society 77th Annual Forum","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126399812","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 : 2021-05-10DOI: 10.4050/f-0077-2021-16722
R. Jain
Computational Fluid Dynamics (CFD) turbulence transition models are evaluated for rotors in unsteady axial and in forward flight conditions. The study is carried out using CREATETM -AV Helios with NASA codes, Overflow and FUN3D, as the near-body solvers. Three transition models are considered, Amplification Factor Transport (AFT), Langtry-Menter γ-Reθt (LM), and the LM with a crossflow transition model. The LM model is modified to allow for Galilean invariance. The validation study utilizes the data from two recent rotor tests where unsteady transition measurements were obtained on the upper (suction) surface of rotor blades using a novel application of the Differential Infrared Thermography (DIT) technique. The first configuration, the DLR RTG rotor, is a four-blade, 2.13-foot radius rotor in axial flow with pitching blades, operating at Reynolds numbers of 3.2 x 10-5 and 1.7 x 10-5> at three quarter radius, for the two test cases studied. The second configuration, the PSP rotor, is a model-scale, 5.58-foot radius, three-blade rotor in a high-advance-ratio, high-thrust forward flight condition, mounted on a ROBIN-Mod7 fuselage, and operating at a hover Reynolds number of 1.25 x 10-6 at three quarter radius. For this rotor, the validation study also included the DIT measurements on the lower (pressure) surface. Both configurations exhibit large unsteadiness in transition locations. CFD predictions are obtained using consistent grid resolution and numerical settings across the three models and the two rotor configurations. The computed results are analyzed in terms of the rotor transition maps, separation maps, and surface streamlines on the blade upper and lower surfaces. The agreement with the test data is good, in general, including the rapid, unsteady movement of the transition locations.
对旋翼在非定常轴向和前向飞行条件下的湍流转捩模型进行了计算流体力学(CFD)评估。该研究使用CREATETM -AV Helios和NASA代码Overflow和FUN3D作为近体解算器进行。考虑了放大因子输运(AFT)、Langtry-Menter γ-Reθt (LM)和具有横流输运模型的LM三种输运模型。LM模型被修改为允许伽利略不变性。验证研究利用了最近两次转子试验的数据，其中使用差分红外热成像(DIT)技术的新应用，在转子叶片的上(吸力)表面获得了非定常过渡测量。第一种配置是DLR RTG转子，在轴向流动中是一个四叶，半径2.13英尺的转子，带俯伏叶片，在四分之三半径处的雷诺数为3.2 x 10-5和1.7 x 10-5>。第二种配置，PSP旋翼，是一个模型规模的、半径5.58英尺的三叶旋翼，在高推进比、高推力的前飞条件下，安装在ROBIN-Mod7机身上，在四分之三半径处的悬停雷诺数为1.25 x 10-6。对于该转子，验证研究还包括在较低(压力)表面的DIT测量。两种构型在过渡位置都表现出很大的不稳定性。CFD预测是通过三种模型和两种转子配置的一致网格分辨率和数值设置获得的。从转子过渡图、分离图和叶片上下表面流线三个方面对计算结果进行了分析。总的来说，与试验数据吻合较好，包括过渡位置的快速、不稳定运动。
{"title":"CFD Turbulence Transition Models Validation for Rotors in Unsteady Axial and Forward-flight Conditions using CREATETM-AV Helios","authors":"R. Jain","doi":"10.4050/f-0077-2021-16722","DOIUrl":"https://doi.org/10.4050/f-0077-2021-16722","url":null,"abstract":"\u0000 Computational Fluid Dynamics (CFD) turbulence transition models are evaluated for rotors in unsteady axial and in forward flight conditions. The study is carried out using CREATETM -AV Helios with NASA codes, Overflow and FUN3D, as the near-body solvers. Three transition models are considered, Amplification Factor Transport (AFT), Langtry-Menter γ-Reθt (LM), and the LM with a crossflow transition model. The LM model is modified to allow for Galilean invariance. The validation study utilizes the data from two recent rotor tests where unsteady transition measurements were obtained on the upper (suction) surface of rotor blades using a novel application of the Differential Infrared Thermography (DIT) technique. The first configuration, the DLR RTG rotor, is a four-blade, 2.13-foot radius rotor in axial flow with pitching blades, operating at Reynolds numbers of 3.2 x 10-5 and 1.7 x 10-5> at three quarter radius, for the two test cases studied. The second configuration, the PSP rotor, is a model-scale, 5.58-foot radius, three-blade rotor in a high-advance-ratio, high-thrust forward flight condition, mounted on a ROBIN-Mod7 fuselage, and operating at a hover Reynolds number of 1.25 x 10-6 at three quarter radius. For this rotor, the validation study also included the DIT measurements on the lower (pressure) surface. Both configurations exhibit large unsteadiness in transition locations. CFD predictions are obtained using consistent grid resolution and numerical settings across the three models and the two rotor configurations. The computed results are analyzed in terms of the rotor transition maps, separation maps, and surface streamlines on the blade upper and lower surfaces. The agreement with the test data is good, in general, including the rapid, unsteady movement of the transition locations.\u0000","PeriodicalId":273020,"journal":{"name":"Proceedings of the Vertical Flight Society 77th Annual Forum","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132674329","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 : 2021-05-10DOI: 10.4050/f-0077-2021-16870
M. Sugiura, Akira Yoshida, Takuya Furumoto, Kuniyuki Takekawa, K. Kimura, N. Kobiki, H. Sugawara, Y. Tanabe, Yoshiki Iwasaki, Takahiro Noda, Y. Shibata, Tomoka Tsujiuchi, Kentaro Ueda, Hidemasa Yasuda
Aerodynamic characteristics of optimized blade tip geometries for flight at high advance ratio are identified by wind tunnel tests conducted in October 2020. Several types of high-speed compound helicopters are in the development process today after the successful technology demonstrations. JAXA has been studying a high-speed compound helicopter for emergency medical service since it is expected to help save lives significantly in Japan. In this study, optimized blade shapes are invented, whose high-speed performance is twice as high as a conventional blade shape while maintaining hovering performance. In this paper, an optimized rotor blade with a swept-back angle is evaluated highest among optimized rotors and UH-60A rotor in the items of hover performance, high-speed performance, reduction effect of rotor drive power, control hydraulic system output reduction effect, and static aerodynamic stability. Thus, it is concluded that an optimized rotor blade with a swept-back angle is the most practical from the viewpoint of the aerodynamic characteristics of the rotor blade tips.
{"title":"Wind Tunnel Test of Optimal Rotor Blade Tip for a Winged Compound Helicopter at High Advance Ratio","authors":"M. Sugiura, Akira Yoshida, Takuya Furumoto, Kuniyuki Takekawa, K. Kimura, N. Kobiki, H. Sugawara, Y. Tanabe, Yoshiki Iwasaki, Takahiro Noda, Y. Shibata, Tomoka Tsujiuchi, Kentaro Ueda, Hidemasa Yasuda","doi":"10.4050/f-0077-2021-16870","DOIUrl":"https://doi.org/10.4050/f-0077-2021-16870","url":null,"abstract":"\u0000 Aerodynamic characteristics of optimized blade tip geometries for flight at high advance ratio are identified by wind tunnel tests conducted in October 2020. Several types of high-speed compound helicopters are in the development process today after the successful technology demonstrations. JAXA has been studying a high-speed compound helicopter for emergency medical service since it is expected to help save lives significantly in Japan. In this study, optimized blade shapes are invented, whose high-speed performance is twice as high as a conventional blade shape while maintaining hovering performance. In this paper, an optimized rotor blade with a swept-back angle is evaluated highest among optimized rotors and UH-60A rotor in the items of hover performance, high-speed performance, reduction effect of rotor drive power, control hydraulic system output reduction effect, and static aerodynamic stability. Thus, it is concluded that an optimized rotor blade with a swept-back angle is the most practical from the viewpoint of the aerodynamic characteristics of the rotor blade tips.\u0000","PeriodicalId":273020,"journal":{"name":"Proceedings of the Vertical Flight Society 77th Annual Forum","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130411275","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 : 2021-05-10DOI: 10.4050/f-0077-2021-16856
D. Specht, C. Johnson, N. Bouaynaya, G. Rasool
Location data about U.S. heliports is often inaccurate or nonexistent in the FAA's databases, which leaves pilots and air ambulance operators with inaccurate information about where to find safe landing zones. In the 2018 FAA Reauthorization Act, Congress required the FAA to collect better information from the helicopter industry under part 157, which covers the construction, alteration, activation and deactivation of airports and heliports. At the same time, there is no requirement to report private helipads to the FAA when constructed or removed, and some public heliports do not have up to date records. This paper proposes an autonomous system that can authenticate the coordinates in the FAA master database, as well as search for helipads in a designated large area. The proposed system is based on a convolutional neural network model that learns optimal helipad features from the data. We used the FAA's 5010 database and others to construct a benchmark database of rotocraft landing sites. The database consists of 9,324 aerial images, containing helipads, helistops, helidecks, and helicopter runways in rural and urban areas, as well as negative examples, such as rooftop buildings and fields. The dataset was then used to train various state-of-the-art convolutional neural network models. The outperforming model, EfficientNet-bθ, achieved nearly 95% accuracy on the validation set.
{"title":"Intelligent Helipad Detection from Satellite Imagery","authors":"D. Specht, C. Johnson, N. Bouaynaya, G. Rasool","doi":"10.4050/f-0077-2021-16856","DOIUrl":"https://doi.org/10.4050/f-0077-2021-16856","url":null,"abstract":"\u0000 Location data about U.S. heliports is often inaccurate or nonexistent in the FAA's databases, which leaves pilots and air ambulance operators with inaccurate information about where to find safe landing zones. In the 2018 FAA Reauthorization Act, Congress required the FAA to collect better information from the helicopter industry under part 157, which covers the construction, alteration, activation and deactivation of airports and heliports. At the same time, there is no requirement to report private helipads to the FAA when constructed or removed, and some public heliports do not have up to date records. This paper proposes an autonomous system that can authenticate the coordinates in the FAA master database, as well as search for helipads in a designated large area. The proposed system is based on a convolutional neural network model that learns optimal helipad features from the data. We used the FAA's 5010 database and others to construct a benchmark database of rotocraft landing sites. The database consists of 9,324 aerial images, containing helipads, helistops, helidecks, and helicopter runways in rural and urban areas, as well as negative examples, such as rooftop buildings and fields. The dataset was then used to train various state-of-the-art convolutional neural network models. The outperforming model, EfficientNet-bθ, achieved nearly 95% accuracy on the validation set.\u0000","PeriodicalId":273020,"journal":{"name":"Proceedings of the Vertical Flight Society 77th Annual Forum","volume":"16 7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128190341","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 : 2021-05-10DOI: 10.4050/f-0077-2021-16698
Jason K. Cornelius, D. Adams, L. Young, J. Langelaan, T. Opazo, S. Schmitz, Lev Rodovskiy, B. Villac
The Dragonfly lander will enter the Titan atmosphere following an approximate 7–10-year journey through space inside its aeroshell. After atmospheric entry, deployment of the main parachute, and heatshield release, the lander will begin its transition to powered flight (TPF). TPF is a maneuver sequence used for mid-air deployment of the Dragonfly rotorcraft lander. The sequence starts just after lander release with the rotors lightly loaded and finishes when a steadystate descent condition has been attained. Mid-air deployment of a multicopter unmanned aerial system is a multidisciplinary problem involving controller choice and tuning, trajectory planning and optimization, and computational fluid dynamics analyses. This paper is an introduction to the transition of rotor flow states in TPF from the windmill brake state, through the turbulent wake state and vortex ring state, and the successful emergence into a normal operating state. A particle swarm optimized controller’s nominal trajectory is plotted on a rotor aerodynamics state chart to show the trajectory’s path through the flow states along the TPF maneuver. Results of preliminary CFD simulations show the variance of individual rotor thrust and power in the early stages of TPF followed by a successful stabilization of rotor performance. Interactional aerodynamic studies also characterize the pre-release flowfield around the lander to be benign at the start of the maneuver. Additionally, results for the lander in steady axial descent show a previously observed coaxial rotor shielding phenomenon of the upper rotor from the effects of vortex ring state.
{"title":"Dragonfly - Aerodynamics during Transition to Powered Flight","authors":"Jason K. Cornelius, D. Adams, L. Young, J. Langelaan, T. Opazo, S. Schmitz, Lev Rodovskiy, B. Villac","doi":"10.4050/f-0077-2021-16698","DOIUrl":"https://doi.org/10.4050/f-0077-2021-16698","url":null,"abstract":"\u0000 The Dragonfly lander will enter the Titan atmosphere following an approximate 7–10-year journey through space inside its aeroshell. After atmospheric entry, deployment of the main parachute, and heatshield release, the lander will begin its transition to powered flight (TPF). TPF is a maneuver sequence used for mid-air deployment of the Dragonfly rotorcraft lander. The sequence starts just after lander release with the rotors lightly loaded and finishes when a steadystate descent condition has been attained. Mid-air deployment of a multicopter unmanned aerial system is a multidisciplinary problem involving controller choice and tuning, trajectory planning and optimization, and computational fluid dynamics analyses. This paper is an introduction to the transition of rotor flow states in TPF from the windmill brake state, through the turbulent wake state and vortex ring state, and the successful emergence into a normal operating state. A particle swarm optimized controller’s nominal trajectory is plotted on a rotor aerodynamics state chart to show the trajectory’s path through the flow states along the TPF maneuver. Results of preliminary CFD simulations show the variance of individual rotor thrust and power in the early stages of TPF followed by a successful stabilization of rotor performance. Interactional aerodynamic studies also characterize the pre-release flowfield around the lander to be benign at the start of the maneuver. Additionally, results for the lander in steady axial descent show a previously observed coaxial rotor shielding phenomenon of the upper rotor from the effects of vortex ring state.\u0000","PeriodicalId":273020,"journal":{"name":"Proceedings of the Vertical Flight Society 77th Annual Forum","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131919928","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 : 2021-05-10DOI: 10.4050/f-0077-2021-16749
Lori Basham, Justin C. Blankenship, Andrew Koch
The MH-60S NextGen Gunner Seat (NGS) program was established to address serious endurance and chronic injury issues attributed to the legacy seat. This high priority program proceeded at an accelerated pace to meet the fleet’s needs. The program office recognized the important relationships between endurance, injury, anthropometric accommodation, and ergonomics. This paper documents the program’s approach to addressing aircrew accommodation and ergonomics from requirements generation through fielding of the new seat.
{"title":"Anthropometric Accommodation and Ergonomics in the MH-60S NextGen Gunners Seat","authors":"Lori Basham, Justin C. Blankenship, Andrew Koch","doi":"10.4050/f-0077-2021-16749","DOIUrl":"https://doi.org/10.4050/f-0077-2021-16749","url":null,"abstract":"\u0000 The MH-60S NextGen Gunner Seat (NGS) program was established to address serious endurance and chronic injury issues attributed to the legacy seat. This high priority program proceeded at an accelerated pace to meet the fleet’s needs. The program office recognized the important relationships between endurance, injury, anthropometric accommodation, and ergonomics. This paper documents the program’s approach to addressing aircrew accommodation and ergonomics from requirements generation through fielding of the new seat.\u0000","PeriodicalId":273020,"journal":{"name":"Proceedings of the Vertical Flight Society 77th Annual Forum","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134559643","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 : 2021-05-10DOI: 10.4050/f-0077-2021-16822
S. Esteban, Álvaro Blanco
The objective of the presented study is to provide tools for the power plant selection that meet the performance requirements of a VTOL prototype. The tool is integrated in a Mission-Oriented Design Calculator MODC that receives information of the VTOL prototype through a General Block Data (GBD), and then process the information using two algorithms that work together to obtain sub-optimal power plant selections. The data fed to the MODC receives the information of the candidate prototype via four smaller structures that provide geometric, weights, aerodynamic, and propulsive properties that are updated during the iteration process using a series of update rules. This information is then fed to two algorithms: Sensitivity Analysis Algorithm (SAA) and the Fixed-MTOW Analysis Algorithm (FMAA) for the selection of sub-optimal configurations. The SAA generates desired target performance levels for varying aircraft speed (V), propellers' diameter (D), number of engines, and scaling factor SF. The sensitivity analysis provides families of plausible solutions of power plant selections (engine, propeller and batteries) that satisfy the performance target requirements for both axial and longitudinal flight, which are denoted Convergence Zones. The FMAA finds the sub-optimal configuration within the Convergence Zones in order to maximize the Range/Endurance of the UAV for all flight regimes, and extends the study for different combinations for payload and battery mass. After each cycle of iteration the MODC updates the VTOL prototype characteristics in the GBD, hence serving as new data to conduct new sensitivity analysis using the SAA and fine tuning of the FMAA. Results are presented for both algorithms, and conclusions are presented indicating interesting trends towards defining sub-optimal power plant combinations.
{"title":"Parameter Sensitivity studies for the Performance of an Electric BiCP-VTOL UAV","authors":"S. Esteban, Álvaro Blanco","doi":"10.4050/f-0077-2021-16822","DOIUrl":"https://doi.org/10.4050/f-0077-2021-16822","url":null,"abstract":"\u0000 The objective of the presented study is to provide tools for the power plant selection that meet the performance requirements of a VTOL prototype. The tool is integrated in a Mission-Oriented Design Calculator MODC that receives information of the VTOL prototype through a General Block Data (GBD), and then process the information using two algorithms that work together to obtain sub-optimal power plant selections. The data fed to the MODC receives the information of the candidate prototype via four smaller structures that provide geometric, weights, aerodynamic, and propulsive properties that are updated during the iteration process using a series of update rules. This information is then fed to two algorithms: Sensitivity Analysis Algorithm (SAA) and the Fixed-MTOW Analysis Algorithm (FMAA) for the selection of sub-optimal configurations. The SAA generates desired target performance levels for varying aircraft speed (V), propellers' diameter (D), number of engines, and scaling factor SF. The sensitivity analysis provides families of plausible solutions of power plant selections (engine, propeller and batteries) that satisfy the performance target requirements for both axial and longitudinal flight, which are denoted Convergence Zones. The FMAA finds the sub-optimal configuration within the Convergence Zones in order to maximize the Range/Endurance of the UAV for all flight regimes, and extends the study for different combinations for payload and battery mass. After each cycle of iteration the MODC updates the VTOL prototype characteristics in the GBD, hence serving as new data to conduct new sensitivity analysis using the SAA and fine tuning of the FMAA. Results are presented for both algorithms, and conclusions are presented indicating interesting trends towards defining sub-optimal power plant combinations.\u0000","PeriodicalId":273020,"journal":{"name":"Proceedings of the Vertical Flight Society 77th Annual Forum","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124552577","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 : 2021-05-10DOI: 10.4050/f-0077-2021-16807
Ahmad Amer, F. Kopsaftopoulos
With the needs for full structural state awareness and health monitoring as well as emerging challenges of Urban Air Mobility (UAV) and Future Vertical Lift (FVL), Health and Usage Monitoring systems (HUMS) need to be more accurate, robust and reliable than ever before. In active-sensing guided-wave networks in particular, conventional Damage Index (DI)-based approaches have been the industry standard for decades because of their computational simplicity and ability to do the damage detection and quantification tasks. However, under specific circumstances, like for specific actuator-sensor paths within a network or due to varying operational conditions, DIs can suffer from various drawbacks that make them prone to inaccurate and/or ineffective damage quantification. This study builds on previous work by the authors where DIs were used to train single-output Gaussian Process regression models (SOGPRMs) for robust damage quantification, and the accuracy limit of SOGPRMs was shown to depend on the evolution of the chosen DI formulation with damage size. In this study, multi-output GPRMs (MOGPRMs) are used instead in order to leverage information about damage size from multiple actuator-sensor path DI values. It is shown that the proposed approach can overcome the different shortcomings of DI evolution with damage size in the different path by capturing the correlation between the DI evolution for different paths. The proposed framework is applied for an Al coupon with simulated damage, and the damage size quantification results are compared with those of SOGPRMs. It is shown that the information fusion approach exhibited by MOGPRMs gives more accurate damage size estimations compared to SOGPRMs.
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