Browsing Journal of Aerospace Engineering by Title
Now showing items 2148-2167 of 2238
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UAS Collision Avoidance Algorithm Based on an Aggregate Collision Cone Approach
(American Society of Civil Engineers, 2011)A collision-avoidance (CA) algorithm is developed and implemented that is applicable to many different unmanned aerial systems (UAS), ranging from a single platform with the ability to perform all collision-avoidance ... -
UAV Broken-Line Path Following under Disturbance Conditions
(American Society of Civil Engineers, 2018)For the broken-line path following problem of unmanned aerial vehicles (UAVs), to enhance the ability to reject wind disturbance and reduce position error overshoot when a UAV turns in the switching position of a broken-line ... -
UAV Formation Control via the Virtual Structure Approach
(American Society of Civil Engineers, 2015)In this paper, a new formation flying approach based on virtual structure is presented. In this architecture, formation control strategies are appropriate when a large number of unmanned aerial vehicles (UAVs) are involved. ... -
Ultrasonic Lift Measurement Technique for Flow-Induced Structural Vibrations
(American Society of Civil Engineers, 2005)Deficiencies exist in our current ability to measure lift forces in wind-tunnel experiments on vibrating structures in a fluid flow. The ultrasonic lift measurement (ULM) technique has been previously developed to measure ... -
Unbalance Vibration Characteristics and Sensitivity Analysis of the Dual-Rotor System in Aeroengines
(ASCE, 1/1/2021)The unbalance of the rotor system is the main factor causing the vibration of aeroengines. Research on unbalancing vibration coupling, vibration transmission, and vibration sensitivity of inner and outer dual rotors is the ... -
Uncertainty Analysis for Overhead Powerlines by the Generalized Stochastic Perturbation Technique
(ASCE, 7/1/2021)The main aim of this work is to investigate some design uncertainties on the static response of powerline cables. A cable diameter is treated in this study as the design input random parameter distributed according to a ... -
Uncertainty Analysis in Surface Micromachined Force Gauges: Convex Model Approach
(American Society of Civil Engineers, 2004)The paper presents a general framework for analyzing uncertainties in material and geometrical properties of a microforce gauge. Since fabrication of the microgauge is surface micromachining of microelectromechanical systems ... -
Uncertainty Analysis of the Dynamic Responses of a Transmission Tower-Line System Subjected to Cable Rupture
(ASCE, 1/1/2021)Because transmission tower-line systems are always exposed to the natural environment, such structures are vulnerable to various meteorological conditions, and the rupture of a transmission line is a particularly serious ... -
Understanding Flow Characteristics in Metal Additive Manufacturing
(ASCE, 11/1/2021)In fluid flow, the frictional effects from interior surfaces of flow components create pressure loss across the surface. Understanding this inherent pressure loss due to friction and other phenomena is important when ... -
Understanding the Impact of a Serrated Trailing Edge on the Unsteady Hydrodynamic Field
(ASCE, 7/1/2021)Trailing edge noise is a common noise source in aerodynamic applications. Many prior experiments have shown that trailing edge serrations can reduce this noise, but the mechanism by which serrations reduce noise and their ... -
Unified Analysis of Internal Flowfield in an Integrated Rocket Ramjet Engine. I: Transition from Rocket Booster to Ramjet Sustainer
(American Society of Civil Engineers, 2014)A comprehensive numerical analysis was conducted to study the internal flow development in an integrated rocket-ramjet (IRR) propulsion system. The study consists of two parts: transition from the rocket booster to the ... -
Unified Analysis of Internal Flowfield in an Integrated Rocket Ramjet Engine. II: Ramjet Sustainer
(American Society of Civil Engineers, 2014)The flow and combustion dynamics in the ramjet sustainer of an integrated rocket-ramjet (IRR) engine are investigated systematically. The physical model includes the entire engine flowpath, from the freestream in front of ... -
Unified Approach to the Characterization of Coupled Composite Laminates: Benchmark Configurations and Special Cases
(American Society of Civil Engineers, 2010)Benchmark stacking sequence configurations with up to 21 plies are presented for laminates with properties similar to conventional materials, and against which new forms of coupled laminate behavior can be assessed. The ... -
Universal Dynamic Model of the Tethered Space Robot
(American Society of Civil Engineers, 2016)The tethered space robot (TSR) plays a significant role in the noncooperative capture. Compared with traditional space robots and tethered satellite systems, the flexible tether and complex end-bodies bring great challenges ... -
Unstable Oscillation of Rectangular Cylinder at Various Mass Ratios
(American Society of Civil Engineers, 1999)For aerodynamic unstable oscillations, the dynamic properties of a structural system have a strong influence on its response behavior. The mass-damping parameter (the product of the mass ratio and the damping factor), known ... -
Unsteady Aerodynamic Modeling and Analysis of Load Distribution for Helicopter Rotor Blades
(ASCE, 2021-09-21)The complexity of the kinematics and aerodynamics of rotors is a challenging problem for achieving accurate modeling for prediction of rotor loads. The present paper describes an unsteady aerodynamic model based on strip ... -
Unsteady Lift Model for Morphing Airfoil Based on Potential Flow Theory
(American Society of Civil Engineers, 2018)This paper describes the study of unsteady forces acting on a two-dimensional morphing airfoil under the assumption of incompressible, inviscid flow. Through conformal mapping, the flow over a morphing airfoil was mapped ... -
Unsteady MHD Convective Flow of Non-Newtonian Casson Fluid in the Stagnation Region of an Impulsively Rotating Sphere
(American Society of Civil Engineers, 2017) -
Unsteady Oscillatory Stagnation Point Flow of a Jeffrey Fluid
(American Society of Civil Engineers, 2014)In the present paper, the unsteady oscillatory stagnation point flow of a Jeffrey fluid is discussed. The oscillatory stagnation point flows have been discussed in a fixed frame of reference and a moving frame of reference. ...