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Pitching moment

About: Pitching moment is a research topic. Over the lifetime, 3213 publications have been published within this topic receiving 38721 citations.


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Journal ArticleDOI
Abstract: A semiempirical method is presented for the estimation of aerodynamic forces and moments on a steadily rotating airplane model in a spin tunnel. The approach is based on the application of strip theory to determine a part of the aerodynamic coefficient (including rotational velocity) and then estimation of increments to these coefficients because of rotational flow over the stalled airplane. The theory is applied to a light, single-engine, general aviation airplane and the results are compared with the corresponding spin tunnel rotary balance test data.

16 citations

17 Jun 1968
TL;DR: In this paper, the authors presented three numerical methods for obtaining the subsonic load distribution on a thin wing of arbitrary twist and camber: NPL, NLR (Netherlands) and BAC (Warton).
Abstract: Independent numerical methods for obtaining the subsonic load distribution on a thin wing of arbitrary twist and camber have been developed at NPL, NLR (Netherlands) and BAC (Warton), The three methods have been studied jointly and their novel features have been reviewed critically. The best solutions by each method show excellent agreement for wings, at uniform incidence, having smooth leading and trailing edges. Spanwise loading, local aerodynamic centres, lift, pitching moment, vortex drag and chordwise loadings are tabulated for circular and rectangular planforms, for a wing of constant chord with hyperbolic leading and trailing edges, and for a tapered sweptback wing. The convergence of the solutions is examined in detail with respect to separate parameters representing the numbers of spanwise integration points and spanwise and chordwise collocation points. The tapered sweptback planform is considered with different amounts and types of artificial central rounding, but the crucial problem of a central kink under lifting conditions remains a subject for research.

16 citations

Patent
05 May 1980
TL;DR: In this article, an airplane all-moving airfoil having a moment reducing apex for facilitating control of the airfoils is described, where the apex protrudes forward from the leading edge of an all moving horizontal stabilizer and operates through its aerodynamic effect on the stabilizer to reduce the moment required to maintain and vary the position.
Abstract: Disclosed is an airplane all-moving airfoil having a moment reducing apex for facilitating control of the airfoil. In a preferred embodiment, the apex protrudes forward from the leading edge of an all-moving horizontal stabilizer and operates through its aerodynamic effect on the stabilizer to reduce the moment required to maintain and vary the stabilizer position. Counter-rotating airflow vortices produced by the apex reduce the rearward displacement of the center of pressure on the stabilizer as the stabilizer is deflected into an increasing angle of attack. As a result, lighter weight hydraulic stabilizer and elevator actuating mechanisms can be employed. In a preferred embodiment an aeroelastically flexible apex is employed to enhance moment reduction at high angles of attack.

16 citations

Journal ArticleDOI
TL;DR: In this article, the relationship between FTV parameters (nozzle pressure ratio and secondary jet pressure ratio) and FTV performance (thrust pitching angle and thrust pitching moment) was investigated using experiments and numerical simulations.
Abstract: Shock vector control (SVC) in a converging–diverging nozzle with a rectangular cross-section is discussed as a fluidic thrust vectoring (FTV) method. The interaction between the primary nozzle flow and the secondary jet is examined using experiments and numerical simulations. The relationships between FTV parameters [nozzle pressure ratio (NPR) and secondary jet pressure ratio (SPR)] and FTV performance (thrust pitching angle and thrust pitching moment) are investigated. The experiments are conducted with an NPR of up to 10 and an SPR of up to 2.7. Numerical simulations of the nozzle flow are performed using a Navier-Stokes solver with input parameters set to match the experimental conditions. The thrust pitching angle and moment computed from the force-moment balance are used to evaluate FTV performance. The experiment and numerical results indicate that the FTV parameters (NPR and SPR) directly affect FTV performance. Conventionally, FTV performance evaluated by the common method using thrust pitching angle is highly dependent on the location of evaluation. Hence, in this study, we show that the thrust pitching moment, a parameter which is independent of the location, is the appropriate figure of merit to evaluate the performance of FTV systems.

16 citations

Proceedings ArticleDOI
01 Jul 1993
TL;DR: In this article, an analysis of the longitudinal aerodynamics of the Shuttle Orbiter in the hypersonic flight regime is made through the use of computational fluid dynamics (CFD).
Abstract: An analysis of the longitudinal aerodynamics of the Shuttle Orbiter in the hypersonic flight regime is made through the use of computational fluid dynamics (CFD). Particular attention is given to establishing the cause of the 'pitching moment anomaly' which occurred on the Orbiter's first flight and to computing the aerodynamics of a complete Orbiter configuration at flight conditions. Data from ground based facilities as well as Orbiter flight data are used to validate the computed results. Analysis shows that the 'pitching moment anomaly' is a real gas chemistry effect which cannot be simulated in ground-based facilities. Computed flight aerodynamics for the Orbiter are within 5 percent of the measured flight values and trim bodyflap deflections are predicted to within 10 percent.

16 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202353
202294
202168
202076
201983
201886