• 제목/요약/키워드: Rotor Dynamics

Search Result 408, Processing Time 0.024 seconds

Aerodynamic Analysis of Tilt-Rotor Drone Using Computational Fluid Dynamics (전산유체역학을 활용한 틸트로터 드론의 공기역학 해석 연구)

  • Jaemin Han;Byeong-Cheon Kim;Kyoungsik Chang;Khanh Hoan Nguyen;Yongun Yang;Ki-Jung Kwon
    • Journal of Aerospace System Engineering
    • /
    • v.18 no.5
    • /
    • pp.51-60
    • /
    • 2024
  • Variation in rotor angle of a tiltrotor aircraft can significantly impact aerodynamic characteristics of the aircraft. This study utilized Computational Fluid Dynamics (CFD) to analyze aerodynamic performance of a tiltrotor drone with varying flight speeds and rotor angles. The Multiple Reference Frame (MRF) method was applied to simulate the flow generated by the propeller. Trends in lift and drag of the drone across flight modes were analyzed. Degradation in aerodynamic performance under specific flight conditions was examined in terms of changes in effective angle of attack. Results showed that the more negative the effective angle of attack on the propeller, the greater the degradation in aerodynamic performance. Since the effective attack angle of the propeller changes with rotor angle and flight speed, it is necessary to adjust the propeller's RPM and collective pitch to control the effective attack angle.

Performance Improvement of High Speed Jet Fan

  • Choi, Young-Seok;Kim, Joon-Hyung;Lee, Kyoung-Yong;Yang, Sang-Ho
    • International Journal of Fluid Machinery and Systems
    • /
    • v.3 no.1
    • /
    • pp.39-49
    • /
    • 2010
  • In this paper, a numerical study has been carried out to investigate the influence of jet fan design variables on the performance of a jet fan. In order to achieve an optimum jet fan design and to explain the interactions between the different geometric configurations in the jet fan, three-dimensional computational fluid dynamics and the DOE method have been applied. Several geometric variables, i.e., hub-tip ratio, meridional shape, rotor stagger angle, number of rotor-stator blades and stator geometry, were employed to improve the performance of the jet fan. The objective functions are defined as the exit velocity and total efficiency at the operating condition. Based on the results of computational analyses, the performance of the jet fan was significantly improved. The performance degradations when the jet fan is operated in the reverse direction are also discussed.

Dynamic Modeling and Stabilization Techniques for Tri-Rotor Unmanned Aerial Vehicles

  • Yoo, Dong-Wan;Oh, Hyon-Dong;Won, Dae-Yeon;Tahk, Min-Jea
    • International Journal of Aeronautical and Space Sciences
    • /
    • v.11 no.3
    • /
    • pp.167-174
    • /
    • 2010
  • The design, dynamics, and control allocation of tri-rotor unmanned aerial vehicles (UAVs) are introduced in this paper. A trirotor UAV has three rotor axes that are equidistant from its center of gravity. Two designs of tri-rotor UAV are introduced in this paper. The single tri-rotor UAV has a servo-motor that is installed on one of the three rotors, which enables rapid control of its motion and its various attitude changes-unlike a quad-rotor UAV that depends only on the angular velocities of four rotors for control. The other design is called 'coaxial tri-rotor UAV,' which has two rotors installed on each rotor axis. Since the tri-rotor type of UAV has the yawing problem induced from an unpaired rotor's reaction torque, it is necessary to derive accurate dynamic and design control logic for both single and coaxial tri-rotors. For that reason, a control strategy is proposed for each type of tri-rotor, and nonlinear simulations of the altitude, Euler angle, and angular velocity responses are conducted by using a classical proportional-integral-derivative controller. Simulation results show that the proposed control strategies are appropriate for the control of single and coaxial tri-rotor UAVs.

파워 효과를 고려한 스마트 무인기의 공력해석

  • Kim, Cheol-Wan;Chung, Jin-Deog
    • Aerospace Engineering and Technology
    • /
    • v.4 no.1
    • /
    • pp.39-44
    • /
    • 2005
  • To validate the rotor performance analysis, 3D Computational Fluid Dynamics(CFD) analysis was performed for tilt rotor aeroacoustic model(TRAM). Also, 3D vehicle with rotating rotors was simulated for rotor power effect analysis. Multiple reference frame(MRF) and sliding mesh techniques were implemented to capture the effect of rotor revolution. CFD results were compared with the wind tunnel test results to validate their accuracy. At helicopter mode, CFD analysis predicted lower thrust than the wind tunnel test but CFD results showed good agreement with the test result at cruise mode. Rotor power effect decreased the lift but did not change drag and pitching moment.

  • PDF

Dynamic Response Analysis of a Flexible Rotor During Impact on Backup Bearings (탄성 로터의 백업베어링 충돌 시 동적 응답 해석)

  • Park, K.J.;Bae, Y.C.
    • Journal of Power System Engineering
    • /
    • v.16 no.3
    • /
    • pp.22-28
    • /
    • 2012
  • Active magnetic bearings(AMBs) present a technology which has many advantages compared to traditional bearing concepts. However, they require backup bearings in order to prevent damages in the event of a system failure. In this study, the dynamics of an AMB supported rotor during impact on backup bearings is studied employing a detailed simulation model. The backup bearings are modeled using an accurate ball bearing model, and the model for a flexible rotor system is described using the finite element approach with the component mode synthesis. Not only the influence of the support stiffness, clearance and friction coefficient on the rotor orbit, but also bearing load are compared for various rotor system parameters. Comparing these results it is shown that the optimum backup bearing system can be applicable for a specific rotor system.

Review of Reaction Drive Rotor System Sizing Methodology (반작용 구동로터 시스템의 사이징 방법론에 대한 고찰)

  • Ali, Freshipali Rasheeth;Jeon, Kwon-Su;Lee, Jae-Woo
    • 한국항공운항학회:학술대회논문집
    • /
    • 2016.05a
    • /
    • pp.9-13
    • /
    • 2016
  • Reaction drive rotor system is capable of providing hover and low speed capabilities to different aircraft concepts such as stopped rotor wing, canard rotor wing, compound gyroplane etc. Existing sizing and analysis tools for shaft drive rotor system cannot be applied directly to this system. The available methodologies to size this system were reviewed. Power available calculation procedure and factors affects it were addressed prior to sizing process. Various design issues of this system due to interrelationship of internal gas flow dynamics and rotor external aerodynamics was discussed. Finally, a modification that is required in existing sizing methodologies was identified and combined approach in sizing process to consider the interrelationship among engine, rotor and blade duct was introduced.

  • PDF

Dynamic Analysis of a Rotor System Having Thin-walled Cylinder Combined with Its Shaft (회전축에 Thin-walled Cylinder가 결합된 회전체 시스템의 동적 해석)

  • Choi, Young-Hyu;Park, Seon-Kyun;Hoong, Dae-Sun;Chung, Won-Jee
    • Proceedings of the KSME Conference
    • /
    • 2000.04a
    • /
    • pp.631-636
    • /
    • 2000
  • In this paper a transfer method model was introduced in order to analyze critical speeds and vibration modes of a flexible rotor system, whose rotor shaft is cupped into and fitted with a thin-walled cylinder at its end. The computed analysis results were compared with those of the experimental modal test. Both results show good agreement each other. Furthermore the free-run(or run-down) test result for the real rotor system also shows that the proposed transfer matrix method modelling can be successfully applicable to analyzing accurate critical speeds(or natural frequencies) of the rotor system.

  • PDF

HAT Tidal Current Rotor Performance as per various Design Parameter (조류발전 로터 설계변수에 따른 성능 검토)

  • Jo, Chul-Hee;Yim, Jin-Young;Lee, Kang-Hee;Song, Seung-Ho
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2009.11a
    • /
    • pp.590-593
    • /
    • 2009
  • Tidal current power system is one of ocean renewable energies that can minimize the environmental impact with many advantages compared to other energy sources. Not like others, the produced energy can be precisely predicted without weather conditions and also the operation rate is very high. To convert the current into power, the first device encountered to the incoming flow is the rotor that can transform into rotational energy. The performance of rotor can be determined by various design parameters including numbers of blade, sectional shape, diameter, and etc. The stream lines near the rotating rotor is very complex and the interference effects around the system is also difficult to predict. This paper introduces the experiment of rotor performance and also the effect of design parameter on the performance of HAT rotor by CFD.

  • PDF

Numerical and experimental analysis of a 3D printed Savonius rotor with built-in extension plate

  • Altan, Burcin Deda;Kovan, Volkan;Altan, Gurkan
    • Wind and Structures
    • /
    • v.27 no.1
    • /
    • pp.1-9
    • /
    • 2018
  • In this study, the enhancement of the conventional Savonius wind rotor performance with extension plate has been investigated experimentally and numerically. Experimental models used in the study have been produced with 3D (three dimensional) printing, which is one of the rapid prototyping techniques. Experiments of produced Savonius wind rotor models have been carried out in a wind tunnel. CFD (Computational Fluid Dynamics) analyses have been performed under the same experimental conditions to ensure that experiments and numerical analyses are supported to each other. An additional extension plate has been used in order to enhance the performance of the conventional Savonius wind rotor with a gap distance between blades. It can be called modified Savonius rotor or Savonius rotor with built-in extension plate. Thus, the performance of the rotor has been enhanced without using additional equipment other than the rotor itself. Numerical and experimental analyses of Savonius wind rotor models with extension plate have been carried out under predetermined boundary conditions. It has been found that the power coefficient of the modified Savonius rotor is increased about 15% according to the conventional Savonius rotor.

Sensor Fault Detection of Small Turboshaft Engine for Helicopter

  • Seong, Sang-Man;Rhee, Ihn-Seok;Ryu, Hyeok
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2008.03a
    • /
    • pp.97-104
    • /
    • 2008
  • Most of engine control systems for helicopter turboshaft engines are equipped with dual sensors. For the system with dual redundancy, analytic methods are used to detect faults based on the system dynamical model. Helicopter engine dynamics are affected by aerodynamic torque induced from the dynamics of the main rotor. In this paper an engine model including the rotor dynamics is constructed for the T700-GE-700 turboshaft engine powering UH-60 helicopter. The singular value decomposition(SVD) method is applied to the developed model in order to detect sensor faults. The SVD method which do not need an additional computation to generate residual uses the characteristics that the system outputs in direction of the left singular vector if an input is applied in direction of the right singular vector. Simulations show that the SVD method works well in detecting and isolating the sensor faults.

  • PDF