Numerical Analysis of the Effect of Fuselage of Fan-in-body Aircraft on the Pusher Propeller

Jiwook Kang,Jisung Jang,Younghyun You,Youngo Hyun,Jonghun Lee 항공우주시스템공학회 2021 항공우주시스템공학회지 Vol.15 No.2

In this study, CFD analysis was conducted to compare the aerodynamic performance of the isolated propeller and pusher propeller, which is affected by the wake of wide fuselage. The moving reference frame (MRF) method was used for isolated propeller analysis, while the MRF and sliding mesh method were used sequentially for the pusher propeller to analyze the change in the aerodynamic characteristics based on the azimuth angle. Under the same torque condition, the thrust of the pusher propeller was greater than that of the isolated propeller. Thrust increment of the pusher propeller was mainly generated near the root of the blade where the fuselage wake was concentrated. The net efficiency of the pusher propeller was greater than or equal to that of the isolated propeller. Because of the flat fuselage shape, thrust and torque of the pusher propeller periodically changed with the rotation of the propeller.

Investigation and Improvement of Pusher-Propeller Installation Effect for Flying Wing UAV

Wenbo Shi,Jie Li,Shuai Zhao,Zhao Yang 한국항공우주학회 2021 International Journal of Aeronautical and Space Sc Vol.22 No.2

This paper presents a collaborative experimental and numerical research to investigate the influences of the installation of propeller on aircraft aerodynamic performance, and two approaches to mitigate the propeller installation effect are also analyzed. The configuration under investigation is based on a real flying wing unmanned aerial vehicle with a two-bladed pusher-propeller mounted on the aft part of its associated airframe. Reynolds-averaged Navier Stokes simulations coupled with a structured finite-volume cell-vertex based solver are applied to propeller uninstalled and installed configurations, and the numerical results are shown to be in good agreement with the experimental data. The comparative results obtained through prop-uninstalled and prop-installed cases show that the installation of the pusher-propeller leads to the decline of the maximum lift-drag ratio due to aerodynamic interactions between the propeller and airframe. Detailed analysis of the numerical results highlighted that the low pressure areas on the aft part of the airframe generated by the installation of the pusher-propeller will result in an increase of the base drag and hence a decline of the maximum lift-drag ratio. The feasibilities of center shaft extension and the modification of airframe geometry to mitigate the propeller installation effect are verified by numerical simulations, and results showed that proper propeller–airframe spacing and good designs of airframe geometry can effectively improve the flow characteristic and reduce the drag induced by propeller installation effect.

CFD를 이용한 추진식 프로펠러 항공기의 Power-on 효과 해석

조정현(Jeong-Hyun Cho),조진수(Jin-Soo Cho) 한국항공우주학회 2014 韓國航空宇宙學會誌 Vol.42 No.1

프로펠러 추진 항공기의 경우, 프로펠러 power-on 효과는 항공기의 비행성능 및 조종안 정성에 직간접적으로 커다란 영향을 미친다. 본 연구에서는 CFD 기반의 multiple reference frame과 sliding mesh model을 이용하여 power-on 효과가 항공기의 공력특성에 미치는 영향을 해석하였다. 프로펠러 power-on 효과에 의해 양력이 미소하게 증가하고 최대양력이 증가되며 실속이 지연된다. 반면, 프로펠러 power-on 효과에 의해 항력이 크게 증가하여 양항비가 감소된다. 또한, 프로펠러 power-on 효과에 의해 기수내림 피칭 모멘트가 감소하여 종방향 정안정성이 감소된다. 본 연구를 통해 획득한 프로펠러 power-on 해석결과는 항공기 성능 및 조종안정성 해석에 중요한 자료로 활용되어 추진식 프로펠러 항공기 개발에 기여할 수 있을 것으로 기대된다. In the case of a propeller-driven aircraft, power-on effect generated by the propeller has a strong influence on the performance and the stability of an aircraft directly and indirectly. A numerical study on the power-on effect has been performed using the CFD based on the multiple reference frame and sliding mesh model. The power-on effect increases the overall lift and the maximum lift of the aircraft. In addition to lift increment, power-on effect delays the stall of the aircraft. On the other hand, the power-on effect increases the drag significantly and consequently decreases the lift-to-drag ratio of the aircraft. Furthermore, the power-on effect decreases the nose-down pitching moment and consequently decreases the longitudinal static stability of the aircraft. It is expected that the analysis results presented and discussed in this report will be used as an important material for analyzing the aircraft performance and stability and will contribute the development of the propeller-driven aircraft with the pusher propeller.

추진식 프로펠러 무인항공기의 Power-on 효과 해석

조정현,김영태 한국항공우주학회 2013 한국항공우주학회 학술발표회 논문집 Vol.2013 No.11

Power-on 효과는 항공기의 비행성능 및 조종안정성에 커다란 영향을 미친다. 본 연구에서는 CFD 기반의 MRF 와 SMM 을 이용하여 power-on 효과가 항공기의 공력특성에 미치는 영향을 해석하였다. Power-on 효과에 의한 양력 증가는 주로 날개에서 발생한다. 프로펠러 후류에 의해 날개의 양력이 증가되나 내리흐름 증가에 의해 수평 꼬리날개의 양력이 감소되어 항공기 전체 양력은 미소하게 증가한다. Power-on 효과에 의한 항력은 주로 동체에서 발생한다. 프로펠러 후류에 의해 동체의 압력 항력이 증가되어 항공기 전체 항력은 증가된다. 또한, 프로펠러 후류에 의해 내리흐름이 증가하여 항공기의 노즈다운 피칭 모멘트가 감소한다. Power-on 해석결과는 항공기의 성능 및 조종안정성 해석에 중요한 자료로 활용되며 특히 추진식 프로펠러 무인항공기 개발에 기여할 수 있을 것으로 기대된다. The power-on effect contributes to the performance and the stability of an aircraft directly and indirectly. Numerical study on the power-on effect of an UAV with a pusher propeller is performed using the CFD. The slipstream created by the propeller increases the lift of the wing. On the other hand, the downwash increase in the vicinity of the tail decreases the lift of the tail. Therefore, the overall lift of the aircraft is increased slightly. The slipstream increases the pressure drag of the fuselage and consequently increases the overall drag of the aircraft. Moreover, increase of the downwash decreases the nose-down pitching moment of the aircraft. It is believed that the analysis results presented and discussed in this report will assist the aerodynamic designer in estimating quantitatively the performance and the stability of the aircraft and contribute the development of the UAV with a pusher propeller.

전진용 프로펠러가 추가된 쿼드로터의 모델링 및 제어법칙 설계

김효원(Hyowon Kim),노민식(Minshik Roh),정진석(Jinseok Jeong),강범수(Beomsoo Kang) 한국항공우주학회 2017 한국항공우주학회 학술발표회 논문집 Vol.2017 No.11

Wing Tip Mounted Tractor and Pusher Propellers- Comparison with Conventional Layout : A Numerical Study

Y Chandukrishna,T N Venkatesh 한국전산유체공학회 2022 한국전산유체공학회 학술대회논문집 Vol.2022 No.10

소형항공기용 왕복엔진의 정적 성능시험 연구

김근배(Keun-Bae Kim),안석민(Seok-Min Ahn),김근택(Keun-Taek Kim),최선우(Sun-Woo Choi) 한국추진공학회 2003 한국추진공학회지 Vol.7 No.3

Pusher 프로펠러로 추진되는 인간 동력 항공기의 개념설계 및 성능 해석

이동훈,신교식,안존 한국항공우주학회 2012 한국항공우주학회 학술발표회 논문집 Vol.2012 No.4

항속거리 보다는 속도 성능에 초점을 맞춘 인간 동력 항공기를 설계하는 과정에서, Pusher 프로펠러를 장착한 사례가 항공기 중량 면에서 유리한 점을 발견하였으며, 이를 적용하여 개념설계를 수행하였다. 이착륙시 또는 낮은 고도의 비행시 날개가 지면으로부터 이격되어 손상을 막을 수 있도록 고익기 형태를 취하였으며, 우수한 속도 성능을 갖도록 높은 익면하중을 갖도록 하였다. 프로펠러를 최적 설계하여 추력성능을 해석하였으며, 이를 바탕으로 항공기의 이륙 성능 및 순항 성능을 해석하였다. 동력전달 장치로는 조종사 전방에서 뫼비우스의 띠 형식으로 비틀어진 체인 전달 장치로서 테일 붐을 관통하는 프로펠러 구동축에 직접 전달되는 방식을 채택하여 구동 메커니즘의 중량 절감을 시도하였고, 동력전달 효율을 높이고 신뢰성을 확보하도록 하였다. During the conceptual design process of a human powered aircraft (HPA), the configuration with a pusher propeller has been found to have good potential in reducing the structural weight of the aircraft, which has been applied to the HPA currently being developed. The resulting HPA design employs a cantilever high-wing, which has been the trend of most successful HPAs, with proper ground clearance during landing and low altitude flight. An propeller has been optimally designed with vortex theory, which has been used to estimate the performance of the aircraft in take-off and cruise flight. A chain rink mechanism, twisted in the manner of the Mobius' belt, is located in front of the pilot, driving the propeller shaft which runs through the tail boom. The proposed power-transmission-mechanism is expected to reduce the structural weigh, while securing the reliability and high power transmission efficiency.

Numerical Study of Wing Tip-Mounted Tractor and Pusher Propellers in Comparison with Conventional Layout

Y. Chandukrishna,T. N. Venkatesh 한국항공우주학회 2023 International Journal of Aeronautical and Space Sc Vol.24 No.4

The purpose of this study is to compare the aerodynamic characteristics of the wing when the propeller is placed in different positions, namely in the conventional, tip-mounted tractor, and pusher configurations. Numerical studies were carried out by solving steady RANS equations in the flow field. The propeller is approximated as a disk of infinitesimal thickness. The propeller blade loading is calculated using the blade element method using the details of propeller geometry and airfoil characteristics. Studies were performed for the angles of attack in the linear range, varying the direction of rotation of propeller for all three configurations at the same advance ratio. Wing tip-mounted tractor configuration with inboard-up rotation gives higher lift and lower drag than the other two configurations, and wing tip-mounted propeller in tractor configuration with outboard-up rotation gives lower lift and higher drag. Along with the results from the numerical studies, a conceptual model is put forth using the basic vortex systems of the wing and propeller to explain the observed results.

복합형 회전익기의 푸셔 프로펠러 최적 설계에 대한 상쇄 연구

유영현(Younghyun You),장지성(Jisung Jang),현영오(Young-O Hyun),김유경(Yoo Kyung Kim),이광현(Kwang Hyun Lee),임종봉(Jong Bong Yim),이종훈(Jong Hoon Lee) 한국항공우주학회 2019 한국항공우주학회 학술발표회 논문집 Vol.2019 No.4