This paper investigates energy budget characteristics of mobile base stations (BSs) having the form unmanned aerial vehicles (UAVs) equipped with radio frequency (RF) transceivers, intelligent reconfigurable surfaces (IRSs), and renewable sources (RES). The results obtained highlight benefits challenges related to using aforementioned BS, from energy-related point view. specific cases researched...

In this paper, the gravitational search algorithm (GSA) is proposed as a method for controlling opening and closing of airplane wing tires. The GSA used to find optimum proportional-integral-derivative (PID) controller, which controls tires during take-off landing. addition, suggested an approach overcoming absence transfer function, usually required design PID. use expected improve system. Two...

Wing-motion of hovering small fly Liriomyza sativae was measured using high-speed video and flows of the wings calculated numerically. The fly used high wingbeat frequency (≈265 Hz) and large stroke amplitude (≈182°); therefore, even if its wing-length (R) was small (R ≈ 1.4 mm), the mean velocity of wing reached ≈1.5 m/s, the same as that of an average-size insect (R ≈ 3 mm). But the Reynolds ...

This paper demonstrates the application of a numerical methodology for a full-scale aircraft impact crashworthiness investigation. We studied the impact of an aircraft wing with a tree using LS-DYNA and ANSYS CFX. In particular, a detailed finite element model of the wing structure was represented as a box structure containing skin, spars and ribs, and fuel was represented as a distributed mass...

Results of a numerical simulation are presented to determine the feasibility of estimating the location and strength of a wake vortex from imperfect in-situ measurements. These estimates could be used to provide information to a pilot on how to avoid a hazardous wake vortex encounter. An iterative algorithm based on the method of secants was used to solve the four simultaneous equations describ...

A natural laminar flow airfoil has been developed jointly by NASA's Dryden Flight Research and Langley Research Centers a s a part of the aircraft energy efficiency (ACEE) program. A NASA flight program incorporating this airfoil into partial wing gloves on the F-111 TACT airplane was scheduled to start in May, 1980. In support of this research effort, Boeing has conducted a n extensive boundar...

An adaptive backstepping approach to obtain directional control of a xed-wing UAV in presence of unknown crosswind is developed in this paper. The dynamics of the cross track error with respect to a desired trajectory is derived from the lateral airplane equations of motion. Adaptation laws are proposed to estimate the parameters of the unknown disturbances and are employed in closedloop system...

An adaptive backstepping approach to obtain directional control of a fixed-wing UAV in presence of unknown crosswind is developed in this paper. The dynamics of the cross track error with respect to a desired trajectory is derived from the lateral airplane equations of motion. Adaptation laws are proposed to estimate the parameters of the unknown disturbances and are employed in closed-loop sys...