Faculty Publications

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Publications by NITK Faculty

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Subject: search.filters.subject.Aircraft control

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    Aileron endurance test rig design based on high fidelity mathematical modeling
    (Springer-Verlag Wien michaela.bolli@springer.at, 2017) Prasad, M.; Gangadharan, K.V.
    This paper presents a model-based approach to design aileron endurance test rig (ETR). ETR is a dynamic load simulator which simulates aerodynamic load on-ground for verifying and validating the design, performance and stability of aileron actuator. Aileron actuator is a servo-controlled linear hydraulic actuator used to control the movement of ailerons in aircraft. Aileron is one of the primary flight control surfaces which controls roll of the aircraft. In ETR, Aileron actuator acts as unit under test (UUT) while a double-acting linear hydraulic actuator produces a dynamic load with the help of high pressure fluid source and electro-hydraulic servo valve (EHSV). The design of the test rig depends on load and velocity requirements which vary widely over the whole flight envelop and depends on deflection of surface, angle of attack, aircraft speed and altitude. One of the critical factor in designing ETR is to accurately model the interaction between the UUT and load system. This paper presents a simple yet powerful approach of free body diagram to account the power flow between the two systems. Model-based approach allowed to simulate the complete test rig behavior identifying the values of the critical parameters prior to building it. A high fidelity, non-linear mathematical model of aileron ETR is developed, simulated and verified. An appropriate load actuator and its electro-hydraulic servo valve are chosen to meet load and velocity requirements. The minimum rig structure stiffness is determined to ensure the stability of the load control system. A velocity feed-forward-based load controller along with proportional-integral control is implemented and tuned to meet the load control performance satisfactorily. Finally, the developed model is validated against the experimental data from actual test rig. © 2017, Deutsches Zentrum für Luft- und Raumfahrt e.V.
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    AERODYNAMIC ANALYSIS OF WING WITH LEADING EDGE PROTUBERANCES USING PRANDTL’S LIFTING LINE THEORY
    (Begell House Inc., 2022) Sathyabhama, A.; Marathe, A.; Rangapure, S.; Potadar, A.
    The establishment of active or passive flow control techniques over aircraft wings has been an area of continuous effort of experimental as well as theoretical investigations. The passive flow control method of leading edge modification has proven to be effective in improving the lift performance of a wing. Extensive performance analysis of sinusoidal tubercles and the wavy wing has been conducted in the literature. This work aims to determine whether other leading edge geometric modifications like square and triangular protrusions similar to sinusoidal tubercles can provide the same effects. The aerodynamic performance of the wings with sinusoidal, square, and triangular tubercles with amplitudes of 3 mm, 5 mm, 7 mm, and 9 mm and wavelengths of 8 mm, 16 mm, 32 mm, and 64 mm is investigated using Prandtl’s lifting line theory. The effect of wavelength and amplitude variation on lift coefficient (CL) and coefficient of induced drag (CDi) is studied within the prestall regime. The results have shown that CL and CDi reduce and the ratio of these coefficients (CL/CDi) improves for the tubercled wing when compared to the baseline wing. The effect of wavelength variation is found to be negligible. In contrast, amplitude variation showed a maximum increase of CL/CDi in the wing with square tubercles, where it reached 305.15 at 1° AoA, for an amplitude of 9 mm. © 2022 by Begell House, Inc.
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    Numerical Investigation of Gasper Air Jet Dynamics in an Aircraft Cabin
    (Taylor and Francis Ltd., 2023) Srinivasa, V.K.; Kattimani, S.; Reddy C, G.
    Computational fluid dynamics (CFD) is used to analyze the jet interaction of side-vent and gaspers and their influence on cough jets in aircraft cabins. A control device is designed and proposed to be attached to the existing gasper outlet to widen narrow, high-velocity air jet into a widespread air curtain. It forms a shield around the passenger's face, controlling cough droplets from infected passengers entering the co-passengers breathing zone and pushing the high-velocity cough jet toward the floor. A detailed study on flow distribution with existing gaspers and the newly designed control device is presented. The influence and efficacy of the control device in achieving desired flow spread, droplet spread, and intrusion control into co-passengers breathing zones are evaluated. The simulation showed significant droplets were reaching window and aisle passenger breathing zones in the existing gasper, whereas no droplet was found when the control device was introduced. © 2024 Informa UK Limited, trading as Taylor & Francis Group.