Predicting the contribution of running propellers to aircraft stability derivatives

Phillips, Warren F.; Anderson, Elgin A.

doi:10.2514/6.2002-390

Cited by 9 publications

(12 citation statements)

References 2 publications

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“…13 shows theoretical predictions compared with wind-tunnel data for a typical fixed-pitch propeller. 55 …”

Section: Small-angle Rigid-semispan Flapping Of Elliptic Wings Wimentioning

confidence: 97%

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Analytical Decomposition of Wing Roll and Flapping Using Lifting-Line Theory

Phillips

2013

31st AIAA Applied Aerodynamics Conference

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A decomposed Fourier series solution to Prandtl's classical lifting-line theory is used to examine the effects of rigid-body roll and small-angle wing flapping on the lift, induceddrag, and power coefficients developed by a finite wing. This solution shows that, if the flapping rate for any wing is large enough, the mean induced drag averaged over a complete flapping cycle will be negative, i.e., the wing flapping produces net induced thrust. For quasi-steady flapping in pure plunging, the solution predicts that wing flapping has no net effect on the mean lift. A significant advantage of this analytical solution over commonly used numerical methods is the utility provided for optimizing wing flapping cycles. The analytical solution involves five time-dependent functions that could all be optimized, to maximize thrust, propulsive efficiency, and/or other performance measures. Results show that by optimizing only one of these five functions, propulsive efficiencies exceeding 90% can be attained. For the case of an elliptic planform with linear twist, closed-form relations are presented for the decomposed Fourier coefficients and the flapping rate that produces mean induced thrust that balances the mean drag in the absence of wing flapping. Nomenclature n A = Fourier coefficients in the series solution to the lifting-line equation n a = planform coefficients in the decomposed Fourier series solution to the lifting-line equation b = wingspan n b = washout coefficients in the decomposed Fourier series solution to the lifting-line equation i D C = instantaneous wing induced-drag coefficient i D C = mean wing induced-drag coefficient averaged over a complete flapping cycle p D C = wing parasitic-drag coefficient L C = instantaneous wing lift coefficient L C = mean wing lift coefficient averaged over a complete flapping cycle α , L C = wing lift slope α ,L C = airfoil-section lift slope l C = wing rolling moment coefficient A P C = mean available-power coefficient averaged over a complete flapping cycle f P C = instantaneous flapping-power coefficient required to support the flapping rate p f P C = mean flapping-power coefficient averaged over a complete flapping cycle c = local wing section chord length n c = control coefficients in the decomposed Fourier series solution to the lifting-line equation i D = wing induced drag i D = local section induced drag n d = plunging coefficients in the decomposed Fourier series solution to the lifting-line equation n e = plunging coefficients in the Fourier series solution for induced drag, Eq. (29) L = local section lift * Professor, Mechanical and Aerospace Engineering Department, 4130 Old Main Hill. Senior Member AIAA. Downloaded by MONASH UNIVERSITY on November 26, 2014 | http://arc.aiaa.org | l = wing rolling moment N = number of terms retained in a truncated infinite series f P = instantaneous power required to support the instantaneous flapping rate p p = magnitude of the angular wingtip rotation rate about the roll axis p = dimensionless angular wingtip rotation rate about t...

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“…13 shows theoretical predictions compared with wind-tunnel data for a typical fixed-pitch propeller. 55 …”

Section: Small-angle Rigid-semispan Flapping Of Elliptic Wings Wimentioning

confidence: 97%

“…Wind-tunnel data and theoretical predictions for the propulsive efficiencies of a typical fixed-pitch airplane propeller over a range of operating conditions 55. …”

mentioning

confidence: 99%

Analytical Decomposition of Wing Roll and Flapping Using Lifting-Line Theory

Phillips

2013

31st AIAA Applied Aerodynamics Conference

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“…To this aim, the Prandtl-Betz relation coupled to the Prandtl tip-loss factor is solved (Phillips et al, 2003):…”

Section: Bemt Modelmentioning

confidence: 99%

“…The blade element propeller model is based on the generalized theory developed in Phillips et al (2003). With this model, the propeller performances are computed as sum of the contribution from each blade section, modeled as a two-dimensional airfoil.…”

Section: Bemt Modelmentioning

confidence: 99%

Analysis of propeller bearing loads by CFD. Part I: Straight ahead and steady turning maneuvers

et al. 2017

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“…The contribution of the propulsion system to the pitching moment coefficient can be estimated by c x S S C C p p Np Mp   (2) The contribution of the propulsion system to the longitudinal stability is linked to the normal force coefficient, as is shown in Eq.…”

Section: Contribution Of a Running Propeller To The Longitudinal mentioning

confidence: 99%

Contribution of a Running Propeller in the Longitudinal Stability of an Airplane by an Analytical-Empirical Analysis

Taboada

Boschetti

González

2018

2018 AIAA Atmospheric Flight Mechanics Conference

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The objective of the present work is to apply analytical-empirical methods to determine the contribution of a running propeller into the longitudinal stability of a propeller-driven airplane using an analytical-empirical analysis. The method is based on the blade element theory to get the forces and moments associated to the rotating blade; and on the blade vortex theory to estimate the interactions between the airflow across the rotation disk of the propeller and the propeller itself. The purpose is to calculate the impact of the propulsion system on the stability derivatives of the aircraft and estimate the necessary parameters to evaluate the static and dynamic stability in the airplane. Although the pitching moment coefficient becomes a function of the airplane velocity due to the contribution of a running propeller, this does not produce significant effects in static stability. In addition, an automatic pilot was designed to control the longitudinal flight dynamics of the aircraft and non-linear simulations were carried out. The results show that there is no significant difference whether the contribution of a running propeller to the longitudinal flight dynamics on a rigid modeled medium unmanned aircraft is considered or not in the design process of the controller. Nomenclature CL, CD, CM= lift, drag, and pitching moment coefficients CL,α, CD,α, CM,α = lift, drag, and pitching moment slopes CLwb,α, CMwb,α = lift, drag, and pitching moment slopes of the wing-body CLt,α = lift slope of the tail Cl,α = blade-section lift slope Cd = blade-section drag coefficient CMp,α = contribution of the propulsion system to pitching moment slope CM,δt = variation of pitching moment coefficient as function of the throttle opening CNp = propeller normal-force coefficient Cnp = propeller yawing-moment coefficient CQp = propeller torque coefficient CTp = propeller thrust coefficient c = medium chord of the airplane wing cb = blade-section chord length

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Predicting the contribution of running propellers to aircraft stability derivatives

Cited by 9 publications

References 2 publications

Analytical Decomposition of Wing Roll and Flapping Using Lifting-Line Theory

Analytical Decomposition of Wing Roll and Flapping Using Lifting-Line Theory

Analysis of propeller bearing loads by CFD. Part I: Straight ahead and steady turning maneuvers

Contribution of a Running Propeller in the Longitudinal Stability of an Airplane by an Analytical-Empirical Analysis

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