Proceedings of the Vertical Flight Society 76th Annual Forum最新文献

{"title":"Pretest Flutter Predictions of the Upcoming Aeroelastic Tiltrotor Wind Tunnel Test","authors":"Andrew R. Kreshock, Hao Kang, Robert P. Thornburgh, H. Yeo, Jennifer Baggett, Jinwei Shen","doi":"10.4050/f-0076-2020-16436","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16436","url":null,"abstract":"\u0000 This paper discusses current pretest whirl flutter predictions for the TiltRotor Aeroelastic Stability Testbed (TRAST) using two different multi-body dynamic-based rotorcraft comprehensive analysis codes, CAMRAD II and RCAS. The U.S. Army is developing this new tiltrotor system to validate whirl flutter stability analysis, a critical instability mechanism in this type of aircraft. The TRAST model has been fabricated but has not been tested in the wind tunnel. This paper includes component bench testing results with comparisons to the analysis. The predictions include parametric variations of the pitch spring and the control system geometry that can be conducted on the TRAST model.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121289134","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":"Progress Toward a New Conceptual Assessment Tool for Aircraft Cost","authors":"R. Scott, J. Vegh","doi":"10.4050/f-0076-2020-16459","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16459","url":null,"abstract":"\u0000 Progress is updated in an ongoing research effort to develop new analytical capabilities for the conceptual assessment of rotorcraft life-cycle cost. Recent developments in both modeling and implementation are reviewed. New parametric equations are presented for cost elements related to development and operational phases, and a software tool for graphical illustration of cost estimates is demonstrated on selected aircraft. The demonstration utilizes case study aircraft concepts which emphasize the model’s new features for consideration of electric battery-powered aircraft and assessment cases in government acquisition where validation of estimates against legacy fleet aircraft is required. Near-term plans for additions and updates to the cost model are offered in conclusion.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128013355","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":"The Multirotor Test Bed - A New NASA Test Capability for Advanced VTOL Rotorcraft Configurations","authors":"C. Russell, Sarah Conley","doi":"10.4050/f-0076-2020-16370","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16370","url":null,"abstract":"\u0000 In November 2019, NASA completed the first wind tunnel test entry of the Multirotor Test Bed (MTB), a new test capability for advanced VTOL rotorcraft configurations. The MTB had been under development since 2017 when the need arose for an easily reconfigurable test stand for multirotor aircraft configurations. With the wide-ranging assortment of aircraft currently targeted at Urban Air Mobility and Unmanned Aircraft System applications, there is a need for validation data that will increase confidence in the computational modeling tools being used to develop these platforms. The MTB fills this need. This paper describes the key features of the MTB as well as its first wind tunnel test entry. A selection of results from the test is presented here, demonstrating the flexible configuration of the MTB and the types of data researchers can generate using this new test capability.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"31 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125703365","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":"Lichten Award Paper: Experimental Measurements and Low-Order Modeling of Stacked Rotor Performance in Hover","authors":"C. Johnson, J. Sirohi","doi":"10.4050/f-0076-2020-16486","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16486","url":null,"abstract":"\u0000 Coaxial, co-rotating ('stacked') rotors have been shown in the past to increase performance and decrease noise. Due to renewed interest in Urban Air Mobility, research of stacked rotors has increased. This paper reports an experimental study of 1.108 m-radii fixed-pitch stacked rotor with variable axial and azimuthal spacing performed to quantify effects of rotor geometry on total and individual rotor performance. Compared to a conventional, four-bladed rotor, figure of merit was found to increase by 6.4% at small axial spacings. A new rotor concept using azimuthal variation for thrust control was validated. It was observed that total thrust can be varied up to 17% through an azimuthal spacing change of 22.5°. Additionally, a low-order model code, Blade Interaction Prediction (BLIP), was developed to efficiently predict the thrust of closely-spaced rotor blades. BLIP couples vortex element method and blade element momentum theory to combine the effects of chord-wise circulation and rotor inflow. Excellent correlation was observed with experimental results and it was found that small azimuthal angles are most effective to vary total thrust.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121961507","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":"Demonstration of Prop-Rotor System Development for 52kg MTOW Quad-Tilt Prop UAV","authors":"Deog-Kwan Kim, Seong-wook Choi, Danbi Hong, H. Kang, Youngjoong Kee, Taijoo Kim, Myeong-Gyu Lee, S. Wie, C. Yun","doi":"10.4050/f-0076-2020-16449","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16449","url":null,"abstract":"\u0000 Small electric drones (UAVs) were introduced to public people and developed world widely. Companies more than 200 have developed various types of electric drones. Specially the multi-copter which has four propellers, called as quad-copter, was very popular in public people that enjoy personal leisure, sport and hobby. The drone’s technical tendency of worldwide market requested to increase payload, better hover performance and high forward flight speed gradually. Through world market's requirement and technical tendency, KARI had interests in electric drone (UAV) market such as the high flight speed electric drones which have hover and vertical take-off and landing (VTOL) capabilities. In special, the electric UAV which has the reconnaissance and observation mission gives a deep attention to government people, industries and military people. For these targets and goals, KARI had launched to develop 52kg Maximum Take-off Weight (MTOW) Quad-Tilt Prop UAV (QTP UAV) through the previous KARI's smart UAV, rotor system development experience and tilt-rotor technologies. The paper describes that the whole research activity works of its prop-rotor system for QTP UAV. KARI had developed some rotor systems for rotorcraft and UAV more than 20 years. This paper introduces the development of the multidisciplinary design and analysis optimization work for developing prop-rotor system of KARI QTP UAV by using optimization tools which cover better hover and forward flight performance. To research and develop the new prop-rotor system, the new aerodynamic and structural design of propeller had been conducted and these activities were described briefly. Finally, flight demonstration was shown to verify the performance of this prop-rotor system of QTP. For these whole development period, KARI had verified and shown the whole research and development works of the prop-rotor system which as a high performance for QTP UAV founded on main rotor system's previous knowledge and new optimization process.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115814630","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":"Development and Validation of a SPH Bird Model in Abaqus/Explicit Application to the Design of the AW609 Tiltrotor Structure","authors":"Fabrizio Turconi, Riccardo Bay, M. Tirelli, Leonardo Helicopters, Ryan Miller, J. Waterman, Agusta Westland Philadelphia Corp., M. Anghileri, P. Milano","doi":"10.4050/f-0076-2020-16259","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16259","url":null,"abstract":"\u0000 The present paper designs and validates a finite element bird model in order to develop a useful tool for the numerical simulation of an aeronautical bird strike event. The bird is simulated in Abaqus/Explicit environment using the Smoothed-Particle Hydrodynamics (SPH) technique. This formulation is a common approach to the problem, as noticed in many published works that investigate the bird strike problem using other solvers such as LS-Dyna. They are taken as a starting point of the present work in the definition of the bird model initial geometry and equation of state. A comparison and a correlation between some experimental tests and their simulations was conduct, in order to develop and validate the bird numerical model. In particular, impacts against rigid targets, such as plates and wedges, and against deformable ones are evaluated. The result is a validated SPH FE bird model, which can be involved in the next bird strike analysis being a reliable numerical tool.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"2006 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128838829","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":"Architecture And Application Of Hypervisor In FACE Environment With Safety Assurance","authors":"J. Myren, Mitch Groen","doi":"10.4050/f-0076-2020-16427","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16427","url":null,"abstract":"\u0000 Collins Aerospace recognizes the value the warfighter gets from reducing the Size, Weight and Power (SWAP) of the avionics systems. The war fighter also sees benefit from reuse of existing avionics and mission software modules, which frequently vary in software framework and thus are allocated to separate processors. A solution, as seen in the commercial IT industry would be the use of multi-core processing and hypervisors allowing the mixing of frameworks providing rapid integration with minimal SWAP. In avionics we must additionally provide assurance. This paper will explore our application of the FACE™ Technical Standard (Ref. [1]) to obtain framework variability, used in conjunction with a hypervisor to allow the resulting frameworks to exist in a single multi-core processing environment with safety assurance to the solution. The concept proposed was validated through demonstration of US Army and Collins software running on the same multi-core processor.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"55 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128846054","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":"Bell V-280 System Identification and Model Validation with Flight Test Data using the Joint Input-Output Method","authors":"Caitlin Berrigan, Paul Ruckel, Bell, Mark J. S. Lopez, J. Prasad","doi":"10.4050/f-0076-2020-16393","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16393","url":null,"abstract":"\u0000 With modern aerospace vehicle configurations, highly-coupled redundant flight control surfaces are becoming standard practice. For such vehicles, traditional System Identification (SID) methods may not accurately capture the individual contributions of effectors to the vehicle bare-airframe response. A Joint Input-Output (JIO) methodology was used to estimate the control power for each highly-correlated roll effector of the Bell V-280 hover configuration. The methodology was demonstrated using flight test data, where the identification results were compared to a high-fidelity hardware-in-the-loop simulation in the V-280 System Integration Lab.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"2013 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127432855","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":"Attack Helicopter Generations","authors":"Michael Leong","doi":"10.4050/f-0076-2020-16261","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16261","url":null,"abstract":"\u0000 Attack helicopters have gone through several notable changes in development and capabilities throughout their history, changes which are continuing to this day. These changes can be captured in distinct generations of attack helicopters, with significant similarities to generations of fighter aircraft development. Understanding the technological development contained in each generation of attack helicopters gives a relative comparison of the capabilities contained in each and the technology trajectory of improvement. This paper will attempt to categorize attack helicopter development by generations, providing the various characteristics and rationale for each, as well as defining the implications of this development for current design and future attack helicopter improvements.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"292 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133769645","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":"Conceptual Design of UAS Configurations with Dissimilar Rotors","authors":"Nathan E. Beals, Bharath Govindrajan, Rajneesh K. Singh","doi":"10.4050/f-0076-2020-16457","DOIUrl":"https://doi.org/10.4050/f-0076-2020-16457","url":null,"abstract":"\u0000 Three vehicle configurations: a 9 kg quadrotor bi-plane tailsitter, a 20 kg tricopter, and a 450 kg coaxial helicopter with pusher propeller are designed using the iterative rotorcraft sizing framework HYDRA, maximizing payload capacity over missions with both hover and forward flight segments. This methodology allows for vehicles to have constituent rotors of differing geometry and angular velocity, a feature that has just been implemented as a part of this work. It allows users to rapidly evaluate vehicle configurations with rotors of a wide range of size, type, and orientation with respect to the vehicle. Furthermore, HYDRA can now model the electric transmission of power to each rotor separately using individually sized motors and speed controllers according to the requirements of each rotor. Results of the sizing show that vehicle and flow-field symmetry play an important role in whether or not dissimilar rotors may be useful for a specific configuration and mission. Analysis of the coaxial helicopter with pusher propeller demonstrated that by controlling design parameters of the main rotors separately from that of the propeller, operational envelope barriers and optimal aircraft configurations can be explored more thoroughly and more quickly than before.\u0000","PeriodicalId":293921,"journal":{"name":"Proceedings of the Vertical Flight Society 76th Annual Forum","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124319143","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}