Landing gear

About: Landing gear is a research topic. Over the lifetime, 3403 publications have been published within this topic receiving 25370 citations. The topic is also known as: landing gear & gear.

Hard-landing Simulation by a Hierarchical Aircraft Landing Model and an Extended Inertia Relief Technique

Abstract: In this work, an efficient aircraft landing simulation strategy is proposed to develop an efficient and reliable hard-landing monitoring procedure. Landing stage is the most dangerous moment during operation cycle of aircraft and it may cause structural damage when hard-landing occurs. Therefore, the occurrence of hard-landing should be reported accurately to guarantee the structural integrity of aircraft. In order to accurately determine whether hard-landing occurs or not from given landing conditions, full nonlinear structural dynamic simulation can be performed, but this approach is highly timeconsuming. Thus, a more efficient approach for aircraft landing simulation which uses a hierarchical aircraft landing model and an extended inertia relief technique is proposed. The proposed aircraft landing model is composed of a multi-body dynamics model equipped with landing gear and tire models to extract the impact force and inertia force at touch-down and a linear dynamic structural model with an extended inertia relief method to analyze the structural response subject to the prescribed rigid body motion and the forces extracted from the multi-body dynamics model. The numerical examples show the efficiency and practical advantages of the proposed landing model as an essential component of aircraft hard-landing monitoring procedure.

Automatic landing gear device

Abstract: Apparatus to raise or lower the landing gear of semi-trailers, operatable by the driver of the tractor from his cab. A reversible electric motor powers a worm gear that drives a planetary gear system to rotate the gear system which conventionally operates the landing gear ring.

A Comparative Study of Simulated and Measured Main Landing Gear Noise for Large Civil Transports

Abstract: Computational results for the NASA 26%-scale model of a six-wheel main landing gear with and without a toboggan-shaped noise reduction fairing are presented The model is a high-fidelity representation of a Boeing 777-200 aircraft main landing gear A lattice Boltzmann method was used to simulate the unsteady flow around the model in isolation The computations were conducted in free-air at a Mach number of 017, matching a recent acoustic test of the same gear model in the Virginia Tech Stability Wind Tunnel in its anechoic configuration Results obtained on a set of grids with successively finer spatial resolution demonstrate the challenge in resolving/capturing the flow field for the smaller components of the gear and their associated interactions, and the resulting effects on the high-frequency segment of the farfield noise spectrum Farfield noise spectra were computed based on an FWH integral approach, with simulated pressures on the model solid surfaces or flow-field data extracted on a set of permeable surfaces enclosing the model as input Comparison of these spectra with microphone array measurements obtained in the tunnel indicated that, for the present complex gear model, the permeable surfaces provide a more accurate representation of farfield noise, suggesting that volumetric effects are not negligible The present study also demonstrates that good agreement between simulated and measured farfield noise can be achieved if consistent post-processing is applied to both physical and synthetic pressure records at array microphone locations

Earthbound landing gear for aircraft take=off and landing - has carriage on rails with hydraulic capture-release elements, speed matching controllers

Abstract: The earthbound landing gear arrangement has a carriage (2) which bears the aircraft (1) during take-off and landing and whose speed is matched to that of the aircraft via an inductive electrical linear drive. The carriage is guided on a rail (4) forming a take-off and landing strip and carries hydraulic capture (3) devices with latching elements which can be coupled with and released from the aircraft during the landing and launch phases. The aircraft and carriage contain controllers for speed matching, buffers in the capture devices and the latching elements during each phase. USE/ADVANTAGE - Esp. for launching and landing large aircraft. Enables maximum safety to be achieved with very small landing strip area.

Toward noise certification during design: airframe noise simulations for full-scale, complete aircraft

Abstract: An overview of a recent, NASA-sponsored effort to substantially advance simulation-based airframe noise prediction is presented. An accurate characterization of this component of aircraft noise requires a high-fidelity representation of the finer geometrical details associated with the landing gear and wing high-lift devices, such as slats and flaps, which constitute major noise sources. To achieve this ambitious goal, a systematic approach was followed to extend our current state-of-the-art computational tools to a full-scale, complete aircraft in landing configuration within a realistic flight environment. The work involved several phases: high-fidelity, large-scale, unsteady flow simulations; model-scale experiments in ground-based facilities; and farfield noise prediction for a full-scale, complete aircraft. The comprehensive aeroacoustic database generated during the course of the 6-year effort provided a wealth of relevant information for full validation and benchmarking of the advanced computational tools used in the present work. The database will also foster the development of simulation methodologies with improved predictive capabilities.