Evaluation of the Navy's F/A-18A-D powered-approach aerodynamics model

Bonner, Michael S.; Gingras, David R.

doi:10.2514/6.1997-3667

Cited by 4 publications

(4 citation statements)

References 5 publications

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“…Seeds were dried in the sunlight before storage in airtight polybags which were then kept in refrigerator until use. Seeds of uniform size and color were selected to avoid nontreatment variations [26]. Seeds were tested for viability by using water floating method before use.…”

Section: Collection Of Seedsmentioning

confidence: 99%

Effects of Phosphate (Pi) on Seed Germination and Seedling Growth of Cucumis melo L. in Arsenic Supplemented Medium

Afrin

Khan

Hossain

2022

The Chittagong Univ. J. Sci.

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Arsenic (As) is a toxic metalloid widely distributed in the environment posing a serious threat to human health. Enriching the soil with phosphate (Pi) in As condition is believed to reduce the uptake of As in plants. But, it is not clear whether this uptake changes affect the growth behaviors of plant or not. This study, therefore, aimed to determine the efficacy of Pi in balancing the negative effects of As on Cucumis melo as measured in terms of seed germination, seedling growth and biomass production of seedling. The experiment was carried out in petri dish under laboratory conditions in As solution cultures in the absence or presence of Pi. Seeds of C. melo were treated with different concentrations (2, 5 and 10ppm) of As, with or without addition of Pi (10ppm). The results revealed that As exposure hindered germination rate, seedling growth and biomass production of seedling to different magnitudes depending on the concentrations. However, addition of Pi in As solution culture improved the seed germination and seedling growth significantly. Germination were 87% in T1 (2ppm As), 76% in T3 (5ppm As) and 72% in T5 (10ppm As), compared to 90% in T2 (2ppm As+10ppm Pi), 82% in T4 (5ppm As+10ppm Pi) and 77% in T6 (10ppm As+10ppm Pi). In treatments T1 (2ppm As), T3 (5ppm As) and T5 (10ppm As), seedling dry biomasses were 19.8mg, 10.3mg and 7.7mg respectively, which were enhanced to 22.1mg, 15.9mg and 12.1mg respectively in T2 (2ppm As+10ppm Pi), T4 (5ppm As+10ppm Pi) and T6 (10ppm As+10ppm Pi). Similar trend was also recorded for plumule growth, seedling fresh biomass production, seedling vigor, sturdiness etc. Based on the findings, this study recommended the application of Pi to reduce the negative effects of As on C. melo in As solution culture under laboratory condition, that might also be applicable in the field. The Chittagong Univ. J. Sci. 43(1): 51-66, 2021

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Section: Collection Of Seedsmentioning

confidence: 99%

Effects of Phosphate (Pi) on Seed Germination and Seedling Growth of Cucumis melo L. in Arsenic Supplemented Medium

Afrin

Khan

Hossain

2022

The Chittagong Univ. J. Sci.

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“…To gain more insight into the types of errors that occur in the model output, use is made of Theil statistics [28]. Theil's -coefficient is a normalized metric for model quality, and ranges from 1 (worst case) to 0 (perfect fit).…”

Section: Model Validationmentioning

confidence: 99%

“…The error can further divided into a bias error bias , a variance error var , and a covariance error cov . These can be calculated as [28]:…”

Section: Model Validationmentioning

confidence: 99%

Stall Model Identification of a Cessna Citation II from Flight Test Data Using Orthogonal Model Structure Selection

Ingen

Visser

Pool

2021

AIAA Scitech 2021 Forum

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Since 2019, a key element of simulator-based training of airline pilots is stall training. A major and still largely open research question is which level of model fidelity is required for effective training. As part of an effort to answer this question, a model of the quasi-steady stall dynamics of a Cessna Citation II aircraft is identified from flight test data that was specifically collected for this research at an altitude of 5,500 m. To ensure any reductions in elevator and aileron effectiveness during stall were also explicitly measured, the test pilots used additional quasi-random flight test inputs. The considered stall model structure is based on Kirchoff's theory of flow separation. During identification, the nonlinear and linear parameters of the model are estimated in separate, recursively executed, steps. This separation enables the application of a semi-objective model structure selection method using multivariate orthogonal functions for the aerodynamic coefficients included in the model. This approach shows that stall-related effects should be included in the model equations for lift, drag, and pitch moment. Overall, it is found that the model parameters were consistently estimated from the flight test data and that the model accurately describes the aircraft's stall dynamics in the considered flight condition. The developed methodology is concluded to be well-suited for the direct identification of stall models from flight test data.Nomenclature Roman Matrix of regression variables * Specific force in * -direction [m/s 2 ] a Regression variable vector * Force/moment coefficient [-] Average chord length [m] * Angular moment of inertia around * -axis [kgm 2 ] Cost function value Mach number [-] Mass [kg] Amount of time samples Amount of terms in a model structure Roll rate [rad/s] Pitch rate [rad/s] 2

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“…Experience in previous programs has shown that pilots are better able to execute the 3-2-1-1 when they have practiced it in a simulator before flight test. 9 The MFS facility at U.S. Naval Air Warfare Center Aircraft Division Patuxent River, Maryland was utilized for pilot and test team practice.…”

Section: Maneuver Designmentioning

confidence: 99%

Nonlinear Model Development from Flight-Test Data for F/A-18E Super Hornet

Paris

Bonner

2004

Journal of Aircraft

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Applied procedures for nonlinear aerodynamic model development and extraction from flight data for the F/A-18E Super Hornet aircraft are addressed. Parameter identification maneuver design, flight-test support technique, and aerodynamic model development are included. All-axis 3-2-1-1 maneuvers were designed to best excite the longitudinal and lateral-directional system natural frequencies of interest. The work was in support of leading edge flap degraded modes studies for the F/A-18E aircraft investigated by the Naval Air Systems Command. In this flighttest program, the effect of off-schedule, differentially frozen, leading-edge flaps was examined with the aircraft in power-approach configuration. A variety of processes was employed to develop fully nonlinear longitudinal and lateral-directional aerodynamic incremental model corrections. This effort included total aerodynamic coefficient reconstruction from flight-test data and equation error analysis for model structure development/estimation. The available data allowed for the successful extraction of incremental coefficients for aerodynamic forces and moments that resulted in an engineering simulation with increased aerodynamic fidelity in the configurations examined.

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Evaluation of the Navy's F/A-18A-D powered-approach aerodynamics model

Cited by 4 publications

References 5 publications

Effects of Phosphate (Pi) on Seed Germination and Seedling Growth of Cucumis melo L. in Arsenic Supplemented Medium

Effects of Phosphate (Pi) on Seed Germination and Seedling Growth of Cucumis melo L. in Arsenic Supplemented Medium

Stall Model Identification of a Cessna Citation II from Flight Test Data Using Orthogonal Model Structure Selection

Nonlinear Model Development from Flight-Test Data for F/A-18E Super Hornet

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