• Title/Summary/Keyword: Hover performance

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Aerodynamic Calculations in Hover of KUH Rotor Blade (한국형 기동헬기 블레이드의 제자리 비행 공력 해석)

  • Kang, Hee-Jung;Kim, Seung-Ho;Jung, Mun-Seung;Lee, Hee-Dong;Kwon, Oh-Joon
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.25-28
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    • 2008
  • An aerodynamic calculation in hover of KUH main rotor blade is performed using a three-dimensional unstructured hybrid mesh viscous flow solver. The flow solver utilizes a vertex-centered finite-volume scheme that is based on the Roe's flux-difference splitting with an implicit Jacobi/Gauss-Seidel time integration. The eddy viscosity are estimated by the Spalart-Allmaras one-equation turbulence model. A solution-adaptive mesh refinement technique is used for efficient capturing of the tip vortex. Calculations are performed at several operating conditions with varying collective pitch setting for KUH main rotor blade in hover. Good agreements are obtained between the present and other results using HOST and CAMRAD II in overall rotor performance. It is demonstrated that the present vertex-centered flow solver is an efficient and accurate tool for the assessment of rotor performance in hover.

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Assessment of Rotor Hover Performance Using a Node-based Flow Solver

  • Jung, Mun-Seung;Kwon, Oh-Joon;Kang, Hee-Jung
    • International Journal of Aeronautical and Space Sciences
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    • v.8 no.2
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    • pp.44-53
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    • 2007
  • A three-dimensional viscous flow solver has been developed for the prediction of the aerodynamic performance of hovering helicopter rotor blades using unstructured hybrid meshes. The flow solver utilized a vertex-centered finite-volume scheme that is based on the Roe's flux-difference splitting with an implicit Jacobi/Gauss-Seidel time integration. The eddy viscosity are estimated by the Spalart- Allmaras one-equation turbulence model. Calculations were performed at three operating conditions with varying tip Mach number and collective pitch setting for the Caradonna-Tung rotor in hover. Additional computations are made for the UH-60A rotor in hover. Reasonable agreements were obtained between the present results and the experiment in both blade loading and overall rotor performance. It was demonstrated that the present vertex-centered flow solver is an efficient and accurate tool for the assessment of rotor performance in hover.

Development and Verification of Small-Scale Rotor Hover Performance Test-stand (소형 로터 블레이드의 제자리 비행 성능 시험장치 개발 및 검증)

  • Lee, Byoung-Eon;Seo, Jin-Woo;Byun, Young-Seop;Kim, Jeong;Yee, Kwan-Jung;Kang, Beom-Soo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.10
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    • pp.975-983
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    • 2009
  • This paper presents the work being carried out in order to deduce hover performance of a small-scale single rotor blade as a preliminary study of a small coaxial rotor helicopter development. As an initial research, a test stand capable of measuring thrust and torque of a small-scale rotor blade in hover state was constructed and fabricated. The test stand consists of three parts; a rotating device, a load measuring sensor and a data acquisition system. Thrust and torque were measured with varying collective pitch angle at fixed RPM. Through this research, hover performance tests were conducted for a small-scale single rotor blade operating in low Reynolds number ($Re\;{\approx}3{\times}10^5$), as well as for verifying the test stand itself for acquiring hover performance.

Tethered Hover Test for Small Scaled Tilt-rotor UAV (축소형 틸트로터 무인기의 안전줄 호버 시험)

  • Park, Bum-Jin;Yoo, Chang-Sun;Chang, Sung-Ho;Choi, Seong-Wook;Koo, Sam-Ok;Kang, Young-Shin
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.15 no.4
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    • pp.9-16
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    • 2007
  • Tilt rotor aircraft can take off and land vertically and cruise faster than any other helicopter. A scaled flight demonstration model of a tilt rotor aircraft has been developed by KARI. Because the flight characteristics of tilt rotor are not well known, the developed scaled model would be helpful to evaluate flight control algorithm of a full scale aircraft. The tethered hover test has been performed in order to improve hover flight characteristics of tilt rotor aircraft prior to flight test of the small scaled model. During the tethered hover test, the performance of rotor speed governor, rate SAS (Stability Augmentation System) and control surface mixers have been evaluated. We expect that the results of real flight hover test would be quite same as tethered hover test. Therefore the tethered hover test results will reduce the risk of flight test properly by fixing some of hidden problems which might occur during the flight test. This paper presents the results of tethered hover test in detail and shows how it could be final ground test before flight test. The control mixer gain and rate SAS feedback gains were modified in order to get higher controllability and stability during the tethered hover flight. The rotor governor showed that it could keep rotor RPM constant with very small deviation even during severe pilot collective input change. The tethered hover test results gave pilot and engineers confirmation and experience about the scheduled flight test.

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Prediction of Hover Performance on Development of Small-Scale UAV using Numerical and Experimental Approach (실험을 통한 소형 무인헬리콥터의 공력인자 도출 및 제자리 비행 성능 예측)

  • Lee, Byoung-Eon;Kim, Sang-Deok;Byun, Young-Seop;Song, Jun-Beum;Kang, Beom-Soo
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2548-2553
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    • 2008
  • Prediction of the rotor blade performance is important for determining design factors such as weight and size in development of a small-scale helicopter. Generally, prediction of helicopter performance means the estimation of the power required for a given flight condition. However, due to lack of test data and analyzed results for small-scale rotor blade operated at low Reynolds numbers ($Re{\approx}10^5$), this is not an easy task. As an initial research, this work performs a modeling of a single rotor configuration with FLIGHTLAB and a experimental research with rotor test bed. In this process, we performed small-scale isolated single rotor by experimental and numerical method and achieved good agreement of the hover performance on the test data and simulation results.

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Event-Triggered H2 Attitude Controller Design for 3 DOF Hover Systems (3 자유도 비행체 시스템의 이벤트 트리거 기반의 H2 자세 제어기 설계)

  • Jung, Hyein;Han, Seungyong;Lee, Sangmoon
    • IEMEK Journal of Embedded Systems and Applications
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    • v.15 no.3
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    • pp.139-148
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    • 2020
  • This paper is concerned with the H2 attitude controller design for 3 degree of freedom (DOF) Hover systems with an event-triggered mechanism. The 3 DOF Hover system is an embedded platform for unmanned aerial vehicle (UAV) provided by Quanser. The mathematical model of this system is obtained by a linearization around operating points and it is represented as a linear parameter-varying (LPV) model. To save communication network resources, the event-triggered mechanism (ETM) is considered and the performance of the system is guaranteed by the H2 controller. The stabilization condition is obtained by using Lyapunov-Krasovskii functionals (LKFs) and some useful lemmas. The effectiveness of the proposed method is shown by simulation and experimental results.

Performance predictions and acoustic analysis of the HVAB rotor in hover

  • Mali, Hajar;Benmansour, Kawtar;Elsayed, Omer;Qaissi, Khaoula
    • Advances in aircraft and spacecraft science
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    • v.9 no.4
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    • pp.319-333
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    • 2022
  • This work presents a numerical investigation of the aerodynamics and aero acoustics of the HVAB rotor in hover conditions. Two fully turbulent models are employed, the one-equation Spalart-Allmaras model and the two-equation k-ω SST model. Transition effects are investigated as well using the Langtry-Menter γ-Re θt transition transport model. The noise generation and propagation are being investigated using the Ffows-Williams Hawking model for far-field noise and the broadband model for near-field noise. Comparisons with other numerical solvers and with the PSP rotor test data are presented. The results are presented in terms of thrust and power coefficients, the figure of merit, surface pressure distribution, and Sound pressure level. Velocity, pressure, and vortex structures generated by the rotor are also shown in this work. In addition, this work investigates the contribution of different blade regions to the overall noise levels and emphasizes the importance of considering specific areas for future improvements.

Development of Coaxial Propeller Test Facility and Experimental Study on Hover Performance Characteristics for Drone (드론용 동축 프로펠러 시험장치 개발 및 제자리비행 성능특성에 대한 실험적 연구)

  • Song, Youn-Ha;Kim, Deog-Kwan
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.1
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    • pp.59-67
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    • 2018
  • In this paper, the test facility for coaxial propellers at low Reynolds developed and validated by measured data. The test equipment was designed to measure the hovering performance of propellers according to distances between the upper/lower propellers. Thrust, torque, rotational speed, vibration, and amperage of upper and lower propellers can be measured separately. The data acquisition system was built to collect signals of sensors, and LabVIEW software was used to control the motor and collect the signal. The hover performance tests of single propellers were preceded for the facility validation, and then the performance values of coaxial propellers were measured according to distances and diameter differences between the upper/lower propellers. The results showed that the high efficiency is achieved at 20%~30% distance between the upper propeller and lower one. The configuration that the upper propeller has shorter diameter than the lower one has the highest efficiency than other configuration.

Test and Evaluation of the Propeller Developed for a Multi-copter with the Take-off Weight of 25 kg (이륙 중량 25 kg급 멀티콥터용 프로펠러 시험 평가)

  • Kang, Hee Jung;Kim, Taejoo;Wee, Seong-Yong
    • Journal of Aerospace System Engineering
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    • v.12 no.4
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    • pp.26-34
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    • 2018
  • Structural static test and the performance test were conducted to determine whether the propeller developed for a multi-copter with the take-off weight of 25 kg satisfies the design requirement. The result of the structural test revealed that the propeller had a safety margin of 3 or more as the ultimate load and requirement load did not cause the specimen breakage. In the performance test, the propeller generated the hover thrust and maximum thrust of design requirement, and hover efficiency in the operating thrust range was greater than 0.73. Maximum hover efficiency increased by more than 3% compared to the reference propeller and electric power consumption decreased by more than 4% in the operating range. The propeller was found to be successfully developed based on the satisfaction rate of the structural strength requirement and the performance requirement.

Developed a test rig for studying the hover performance of a coaxial propeller (동축반전 프로펠러의 제자리 비행 성능연구를 위한 시험장치 개발)

  • Song, Youn-Ha;Song, Jae-Rim;Kim, Deog-Kowan
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.560-562
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    • 2017
  • This paper presents the development and test results of a test rig for confirming the hover performance of the coaxial propeller which is applied to the drone in order to carry out the mission that requires high payload such as the development of the courier drones. the performance of each propeller was measured by varying the thrust and torque according to the H/D ratio. the Thrust sensor and torque sensor were used to measure the thrust and torque generated when the propeller rotated, and a photo sensor was used to measure the rpm. it used the data acquisition system to acquire data from each sensor, and used the Labview softwaer to control data storage, monitoring and BLDC motor control. In the test, each propeller meansured the figure of mefit according to the chansge of the interval at the same rpm.

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