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Full-Text Articles in Engineering
Thrust Vector Control Of An Upper-Stage Rocket With Multiple Propellant Slosh Modes, Mahmut Reyhanoglu, Jaime Rubio Hervas
Thrust Vector Control Of An Upper-Stage Rocket With Multiple Propellant Slosh Modes, Mahmut Reyhanoglu, Jaime Rubio Hervas
Physical Sciences - Daytona Beach
“The thrust vector control problem for an upper-stage rocket with propellant slosh dynamics is considered. The control inputs are defined by the gimbal deflection angle of a main engine and a pitching moment about the center of mass of the spacecraft. The rocket acceleration due to the main engine thrust is assumed to be large enough so that surface tension forces do not significantly affect the propellant motion during main engine burns. A multi-mass-spring model of the sloshing fuel is introduced to represent the prominent sloshing modes. A nonlinear feedback controller is designed to control the translational velocity vector and …
Modeling And Control Of Space Vehicles With Fuel Slosh Dynamics, Mahmut Reyhanoglu
Modeling And Control Of Space Vehicles With Fuel Slosh Dynamics, Mahmut Reyhanoglu
Physical Sciences - Daytona Beach
"Ever since the launch of the early high-efficiency rockets, controlling liquid fuel slosh within a launch vehicle has been a major design concern. Moreover, with today's large and complex spacecraft, a substantial mass of fuel is necessary to place them into orbit and to perform orbital maneuvers."--from the book's introduction
Lidar Observations Of Elevated Temperatures In Bright Chemiluminescent Meteor Trails During The 1998 Leonid Shower, Xinzhao Chu, Alan Z. Liu, George Papen, Chester S. Gardner
Lidar Observations Of Elevated Temperatures In Bright Chemiluminescent Meteor Trails During The 1998 Leonid Shower, Xinzhao Chu, Alan Z. Liu, George Papen, Chester S. Gardner
Physical Sciences - Daytona Beach
Seven persistent trails associated with bright fireballs were probed with a steerable Na wind/temperature lidar at Starfire Optical Range, NM during the 17/18 Nov peak of the 1998 Leonid meteor shower. These chemiluminescence trails were especially rich in Na. The average Na abundance within the trails was 52% of the background Na layer abundance, which suggests that the corresponding masses of the meteors were from 1 g up to 1 kg. CCD images show that the chemiluminescent emissions (including Na and OH) are confined to the walls of a tube, which expands with time by molecular diffusion. Lidar profiles within …
A Model For Calculating Acoustic Gravity Wave Energy And Momentum Flux In The Mesosphere From Oh Airglow, Gary R. Swenson, Alan Z. Liu
A Model For Calculating Acoustic Gravity Wave Energy And Momentum Flux In The Mesosphere From Oh Airglow, Gary R. Swenson, Alan Z. Liu
Physical Sciences - Daytona Beach
Acoustic gravity and tidal waves propagating in the mesosphere/lower thermosphere (80-110 km) perturb the airglow layer intensities. The OH airglow has recently been modeled to determine the relationship between the relative perturbed atmospheric density and temperature (ρ’/ ρ, T’/T) to the OH intensity ( I’OH/IOH ) at the OH emission altitudes [Swenson and Gardner, 1997]. A model is presented here which relates wave perturbed OH airglow to the wave energy and momentum flux as they propagate through the emission layer. The model is dependent on the wave horizontal and vertical wavelengths (or phase speed as related through …