Proceedings of the Vertical Flight Society 78th Annual Forum最新文献

{"title":"M-Star Medical Transport with a Multi-Ducted Angled Rotor Design","authors":"Liza Pierce, Michael Johnson, Richard Catania, Stuart Dana, Thomas Johnson","doi":"10.4050/f-0078-2022-17454","DOIUrl":"https://doi.org/10.4050/f-0078-2022-17454","url":null,"abstract":"\u0000 This paper discusses the benefit of the multi-ducted angled rotor (M-DAR) distributed electric propulsion system in a V/STOL aircraft called the M-Star. The M-DAR propulsion system consists of an array of fixed pitched ducted fans. Traditional fan-in-wing designs can suffer from pitch up effects, stall, instability, and momentum drag when transitioning to forward flight as the oncoming air vector increases. In such planar orientations the air must accelerate rapidly into the ducted fan to prevent blade instability. The M-DAR solves these challenges by lowering the angle at which air enters the fans. A 45-degree M-DAR system enables a higher transition speed than 90-degree ducted fans since the air does not need to turn the additional 45-degrees into the ducts. The M-DAR system is comprised of an array of fans which increase the total disk area while the front plate area remains fixed. The fixed fans also eliminate the weight and complexity of actuators-essentially reducing the mechanical challenges of tiltrotor aircraft into programming tasks. In addition, the M-DAR can be operated as a replacement or in conjunction with control surfaces for increased maneuverability and safety. The M-Star incorporates these design benefits which makes the 2-passenger aircraft affordable, safe, and high endurance. SpyDar has successfully developed subscale Group 1 & 2 cargo UAVs using the M-DAR system and intends to scale the concept into the 2-passenger M-Star eVTOL. The mission of this aircraft will be as a medical commuter vehicle for health professionals to rural and underserved areas. \u0000","PeriodicalId":223727,"journal":{"name":"Proceedings of the Vertical Flight Society 78th Annual Forum","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122595441","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":"A Comparison of High-Fidelity Simulation Approaches for Interactional Aerodynamics of Multirotor Systems in Forward Flight","authors":"Abhishek Chopra, Richard Healey, F. Gandhi, O. Sahni","doi":"10.4050/f-0078-2022-17581","DOIUrl":"https://doi.org/10.4050/f-0078-2022-17581","url":null,"abstract":"\u0000 Recent advancements in distributed electric propulsion for urban air mobility applications have made interactional aerodynamics more common on modern rotorcraft designs. Rotor-to-rotor interactions are associated with complex f low features, and require high-fidelity numerical tools for adequate analysis and prediction. The computational cost associated with resolving these aerodynamic interactions can become prohibitively expensive, particularly when simulations over a multitude of operating conditions/configurations are desired. As an alternative to the typical bladeresolved DDES (BR-DDES) approach, an actuator line model with LES (ALM-LES) is considered for its high fidelity aerodynamic prediction capabilities at a reduced computational cost. In this study, flow field and rotor performance predictions using ALM-LES are compared to BR-DDES in order to evaluate the merits of ALM-LES for interactional aerodynamic analysis. Overall, the wake structure of the two-rotor system shows good agreement between the two methods. Integrated thrust is also predicted similarly, with a difference of 2.4% for the front rotor and 4.3% for the aft rotor. While integrated thrust is predicted well by ALM-LES, some discrepancies in sectional thrust are observed in areas with blade-vortex interaction (BVI). The vortex position compares well between the two methods, so the sectional thrust difference is tied to differences in vortex strength and how well ALM is able to represent a BVI. Sectional thrust differences are also observed on the aft rotor and are associated with secondary vortices convecting into the rotor plane. Despite differences in parts of the rotor disk with BVI, ALM-LES is shown to be capable of predicting the interactional aerodynamics of a two-rotor system in forward flight at about 1% the computational cost of BR-DDES.\u0000","PeriodicalId":223727,"journal":{"name":"Proceedings of the Vertical Flight Society 78th Annual Forum","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121640925","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":"Validation of Scanned Propeller Geometry for Simulation Modeling","authors":"Jean-Paul F. Reddinger, Michael P. Avera, Rajneesh K. Singh","doi":"10.4050/f-0078-2022-17643","DOIUrl":"https://doi.org/10.4050/f-0078-2022-17643","url":null,"abstract":"\u0000 3Dscanning technology is used to acquire the airfoil geometry, twist, taper, and chord distribution of several propellers spanning 10-15\" in diameter. Sectional airload properties are then derived from the geometry using the HAM2D computational fluid dynamics solver and construct an RCAS model of each propeller. A comparison between the scan-derived RCAS model and experimentally obtained thrust and torque measurements in hover shows generally reasonable agreement for integrated airloads, with predictions within 5% of thrust and 8% of torque. Representative scanning accuracy error is injected in the model to identify the mode of error which has the largest impact on the predictions, between airfoil geometry (camber), chord length, and twist distribution. It is determined that imprecise scanning and error in the measured twist distribution provides the greatest source of modeling error (5.9%) through this process, likely due the the reliance of these parameters on as little as two scan points. The importance of Reynolds effect modeling at this scale is also confirmed.\u0000","PeriodicalId":223727,"journal":{"name":"Proceedings of the Vertical Flight Society 78th Annual Forum","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127884709","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 Evaluation of Coupling Modes and Haptic Functions enabled by Active Inceptor in Cockpits","authors":"L. Binet, Raphaël Perret","doi":"10.4050/f-0078-2022-17508","DOIUrl":"https://doi.org/10.4050/f-0078-2022-17508","url":null,"abstract":"\u0000 The potential uses of Active Side-Stick Units (ASSU) technology far exceed solely the case of fully programmable haptic feedbacks to one single pilot or the capability to generate haptic cueing for Flight Envelope Protection functions. Indeed, in dual pilot configurations, the capability to electronically link ASSU enables the coupling of the motions of the Pilot Flying (PF) and Pilot Monitoring (PM) controllers and opens potential new modes of communication between pilots, as well as between crew and Automatic Flight Control System (AFCS) when upper modes are engaged. The EFAICTS (Ergonomic impact and new Functions induced by Active Inceptor integration in CockpiTS) project, started in December 2018, received funding from the Clean Sky 2 Joint Undertaking under the European Union's Horizon 2020 research and innovation program under grant agreement No 820884. ONERA was the project coordinator and Safran Electronics & Defense the Topic Leader. The EFAICTS project proposed to develop and integrate coupling and haptic functions for both Pilot/Co-pilot and Crew/Autopilot interactions along a Human-Centered Design approach, in which the end-users (i.e. pilots) were at the heart of the development, from the beginning of the project to the final evaluation phase. The paper focuses on the flight scenarios definition; the PF/PM/AFCS interactions definition; the development of specific haptic feedbacks and ASSU coupling functions. All the concepts developed and assessed through modelling and intermediate tests were finally evaluated by experienced pilots on the ONERA simulation bench. The main results are presented in the paper.\u0000","PeriodicalId":223727,"journal":{"name":"Proceedings of the Vertical Flight Society 78th Annual Forum","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131455092","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":"Automated Inference of Vortex Core Physics of Hovering Rotor Wakes Using Machine Learning Techniques","authors":"J. Abras, N. Hariharan","doi":"10.4050/f-0078-2022-17470","DOIUrl":"https://doi.org/10.4050/f-0078-2022-17470","url":null,"abstract":"\u0000 Machine learning can significantly enhance the insights gained from large aerodynamic computational data sets. Specifically, 3D rotor wake computations produce detailed vortex structures, but typically, only a small fraction of the data is leveraged. A critical limiting factor is the time needed to process these large 3D data sets and infer the correct physics. The development of machine learning methods to process these data sets reduces the data processing burden on the analyst and also increases the volume of data that can be processed within a reasonable amount of time. Recent efforts in this area have resulted in the development of a novel machine learning-based vortex-core data extraction methodology. The present study demonstrates the application of this method to hovering rotor wakes to compare different blade tip geometries, ground effect, wake grid spacing, and collective changes and discusses the extracted vortex physics for each case. \u0000","PeriodicalId":223727,"journal":{"name":"Proceedings of the Vertical Flight Society 78th Annual Forum","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122913012","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":"Evaluation of Flight Control System Architectures for the AH-64","authors":"B. Chu, G. Klein, R. Enns","doi":"10.4050/f-0078-2022-17498","DOIUrl":"https://doi.org/10.4050/f-0078-2022-17498","url":null,"abstract":"\u0000 The AH-64 would significantly benefit from an improved flight control system, particularly as the aircraft's requirements have evolved and continue to do so. To address this, multiple Vehicle Management System architectures are developed and presented for the AH-64 attack helicopter, each addressing several demanding and possibly conflicting future requirements, including Level 1 handling qualities, operating in degraded visual environments, autonomy, high-speed flight operation, and multiple vehicle coordinated operations. Architecture tradeoffs are performed with the understanding that the current AH-64 flight control system is mechanical with electrical partial authority augmentation, but also possesses a non-redundant full authority fly-by-wire emergency backup system. The various architectures are assessed as to how they satisfy the requirements. They are also assessed with respect to their relative costs, both for typical costs such as design, recurring, operating and sustainment, and training as well as other indirect costs such as size and weight. A methodology is developed to compare and contrast the architectures using informal qualitative-based scores assessed by subject matter experts from both industry and customer organizations, as well as scoring from Boeing program management with various operational experiences. The methodology assigns weightings to each requirement and cost criteria through the use of the Analytical Hierarchy Process. The results suggest that there are several likely cost-effective options, possibly with a higher potential return on investment than a conventional fly-by-wire (FBW) architecture. Some of these solutions are also incremental in nature, thereby providing more flexibility than the conventional FBW system. \u0000","PeriodicalId":223727,"journal":{"name":"Proceedings of the Vertical Flight Society 78th Annual Forum","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123858693","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":"Validation of Probabilistic Regime Recognition and Damage Estimation with Large Fleet Datasets","authors":"Dakota Musso, S. Sarkar, Jonathan D. Rogers","doi":"10.4050/f-0078-2022-17554","DOIUrl":"https://doi.org/10.4050/f-0078-2022-17554","url":null,"abstract":"\u0000 Regime recognition (RR) and damage estimation is a critical step in the creation of usage and damage spectra and in development of component replacement timelines. While a variety of methodologies exist for regime recognition based on deterministic classification, recent work has demonstrated the benefit of approaching the problem of regime classification and damage estimation from a probabilistic standpoint. However, while studies have shown the successful deployment of probabilistic algorithms on simulated data, little work has been done to validate their use on large f leet datasets that contain actual flight data. This paper seeks to address two main points. First, the damage estimation scheme proposed in prior work is extended to incorporate uncertainty in the component damage rates, allowing for a complete treatment of the damage estimation problem that fully captures all major sources of uncertainty. Second, this paper exercises the probabilistic regime recognition and damage estimation algorithms published in previous work on 500 hours of actual fleet data, validating the efficacy of the approach. Detailed analysis of the results show that the probabilistic algorithms are effective in estimating flown regimes and component damage fractions and offer unique insights that are not available from comparable deterministic algorithms.\u0000","PeriodicalId":223727,"journal":{"name":"Proceedings of the Vertical Flight Society 78th Annual Forum","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124035472","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":"System Identification and Stitched Modeling of the ADAPT(TM) Winged Compound Helicopter Scaled Demonstrator","authors":"S. Nadell, Christopher DiMarco, T. Berger, Mark J. S. Lopez","doi":"10.4050/f-0078-2022-17576","DOIUrl":"https://doi.org/10.4050/f-0078-2022-17576","url":null,"abstract":"\u0000 Frequency-domain system identification was performed for the ADAPT(TM) Winged Compound Helicopter Scaled Demonstrator, a 10% scale version of the Piasecki X-49A, at four flight conditions spanning its flight envelope. Since the aircraft has eight redundant control effectors - lateral cyclic, longitudinal cyclic, collective, Vectored Thrust Ducted Propeller (VTDP) RPM, rudder, differential flaperon, symmetric flaperon, and elevator - and exhibits a large amount of inter-axis coupling, the Joint Input-Output (JIO) Method was used for system identification in addition to the Direct Method. Based on the identified frequency responses, a hybrid model structure, which explicitly includes the coupled fuselage-rotor flapping dynamics and a first-order model for VTDP RPM lag, was used. State-space models were identified at each flight condition, and combined with trim data to form a full flight envelope stitched simulation model. A detailed analysis of the trends of the stitched model trim, stability and control derivatives, eigenvalues, and frequency responses was performed.\u0000","PeriodicalId":223727,"journal":{"name":"Proceedings of the Vertical Flight Society 78th Annual Forum","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127797409","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":"Safety Considerations on the Operation of Electric Vertical and Takeoff Landing (VTOL) Aircraft at Airports and Vertiports","authors":"G. Le Bris, Loup-Giang Nguyen","doi":"10.4050/f-0078-2022-17610","DOIUrl":"https://doi.org/10.4050/f-0078-2022-17610","url":null,"abstract":"\u0000 Design innovation for electric vertical takeoff and landing (eVTOL) aircraft is accelerating rapidly. By 2025, eVTOL aircraft might be operating commercial flights. Aviation facilities may have to distribute new energy vectors used by eVTOLs. Accommodating these aircraft will require careful planning, as well as design features, standards, and operational procedures to ensure aviation safety. Indeed, these new technologies cannot be turned into a viable air transportation system if they cannot be integrated into existing and future aviation facilities. With the first eVTOL certification on the horizon, a study of potential airside integration issues is timely. This paper identifies and analyzes potential aviation safety hazards and risks specific to the introduction of eVTOL aircraft and hydrogen technologies at airports and vertiports. A review of existing industry standards and ongoing standardization tasks suggests ways to further reduce the most prominent risks through industry standards and practices promoting operational flexibility and interoperability.\u0000","PeriodicalId":223727,"journal":{"name":"Proceedings of the Vertical Flight Society 78th Annual Forum","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116806354","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":"Neuromuscular Response Comparison for Center and Side Stick Positions","authors":"E. Bachelder, Jeff A. Lusardi, B. Aponso","doi":"10.4050/f-0078-2022-17548","DOIUrl":"https://doi.org/10.4050/f-0078-2022-17548","url":null,"abstract":"\u0000 Four Army pilots participated in a simulation experiment to examine the influence of stick location and sensitivity (gain) on pilot neuromuscular (NM) response, performance, and workload. The experiment employed an active inceptor that was positioned between the pilot's legs or, adjacent to the pilot's right side with an armrest. Two stick sensitivities that varied by a factor of four were evaluated using a single-axis compensatory tracking task in the longitudinal and the lateral axes. The experiment results identified two prominent NM modes at roughly 10 and 25 rad/s; stabilizing the elbow implicated the 10 rad/s mode with forearm motion, and wrist/finger motion with the mode at 25 rad/s. With the longitudinal task using the low stick gain, workload ratings were significantly higher for the side stick than the center stick. A preliminary analysis indicated that the greater resisting force between the forearm and non-compliant armrest (side stick configuration) relative to the resisting force between the forearm and leg (center stick configuration) may be a key factor in the higher workload. This suggests that a side stick's gain in the longitudinal axis should be a function of task such that control displacements are generally small. Overall workload during manual tasks would benefit if this approach were applied to all control axes. A second study was conducted to investigate the significant effect of stick gain on crossover frequency that was observed in the first experiment. These results showed that the ratio of stick rate to stick amplitude is directly proportional to crossover frequency, and that a tradeoff between rate and amplitude reflected by changing crossover is similar to the phenomenon described by Fitts Law, where manual movement time is related to the distance travelled. The implications for design are that stick travel can affect performance much more than stick force provided the stick dynamics do not adversely interact with the NM system. It is recommended that the feel system mode should lie between the forearm and wrist/finger NM modes, and that stick sensitivity selection should be based on mission and operating environment. \u0000","PeriodicalId":223727,"journal":{"name":"Proceedings of the Vertical Flight Society 78th Annual Forum","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117054004","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}