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Navigation, Guidance, Control and Dynamics Commons™
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- Active control (1)
- Actuator (1)
- Bluff bodies (1)
- Dynamic stability testing (1)
- EKF (1)
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- Extended Kalman filter (1)
- Forced oscillation (1)
- Ground testing (1)
- Microchannels (1)
- Micron-level (1)
- Murrell’s EKF (1)
- Nanosatelllites (1)
- Noise (1)
- Ogive cylinders (1)
- Parameters (1)
- Picosatellites (1)
- Satellite attitude estimation (1)
- Simulations (1)
- Thermal-fluid control (1)
- Vortex shedding (1)
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Articles 1 - 4 of 4
Full-Text Articles in Navigation, Guidance, Control and Dynamics
Comparison Of Dynamics Stability Testing Techniques With Magnetic Suspension Wind Tunnel Capabilities, Otoniel A. Ramirez, Mark Schoenenberger, David E. Cox, Colin P. Britcher
Comparison Of Dynamics Stability Testing Techniques With Magnetic Suspension Wind Tunnel Capabilities, Otoniel A. Ramirez, Mark Schoenenberger, David E. Cox, Colin P. Britcher
Mechanical & Aerospace Engineering Faculty Publications
Dynamic stability testing techniques currently utilized at NASA Langley Research Center (LaRC) are conducted in multiple facilities and consists of free flight, forced oscillation, and free-to-oscillate tests. The NASA/ODU Magnetic Suspension and Balance System (MSBS) has been recommissioned to explore its utility as an additional facility to expand the dynamic stability test capabilities currently available at NASA LaRC. Simulations were created to replicate each current test facility and method as closely as possible. Data collected from the simulated environments was corrupted with replicated noise sources of the different testing environments and then compared to real data collected during tests when …
Evaluation Of Murrell’S Ekf-Based Attitude Estimation Algorithm For Exploiting Multiple Attitude Sensor Configurations, Sharanabasaweshwara Asundi, Norman Fitz-Coy, Haniph Latchman
Evaluation Of Murrell’S Ekf-Based Attitude Estimation Algorithm For Exploiting Multiple Attitude Sensor Configurations, Sharanabasaweshwara Asundi, Norman Fitz-Coy, Haniph Latchman
Mechanical & Aerospace Engineering Faculty Publications
Pico- and nano-satellites, due to their form factor and size, are limited in accommodating multiple or redundant attitude sensors. For such satellites, Murrell's implementation of the extended Kalman filter (EKF) can be exploited to accommodate multiple sensor configurations from a set of non redundant attitude sensors. The paper describes such an implementation involving a sun sensor suite and a magnetometer as attitude sensors. The implementation exploits Murrell's EKF to enable three sensor configurations, which can be operationally commanded, for satellite attitude estimation. Among the three attitude estimation schemes, (i) sun sensor suite and magnetometer, (ii) magnetic field vector and its …
Experimental Investigation Of Active Control Of Bluff Body Vortex Shedding, Ilteris Koc
Experimental Investigation Of Active Control Of Bluff Body Vortex Shedding, Ilteris Koc
Mechanical & Aerospace Engineering Theses & Dissertations
Mean and fluctuating forces acting on a body are strongly related to vortex shedding generated behind it. Therefore, it is possible to obtain substantial reductions of at least the unsteady forces if vortex shedding is controlled or its regularity is reduced. While conventional active flow control methods are mainly concerned with direct interaction with, and alteration of, the mean flow about a body, modern techniques involve altering existing flow instabilities using relatively small inputs to obtain large-scale changes of mean flows. Aerodynamic flow control may be intended to delay or suppress boundary layer separation through creation of a boundary layer …
Micron-Level Actuator For Thermal-Fluid Control In Microchannels, Nurhak Erbas
Micron-Level Actuator For Thermal-Fluid Control In Microchannels, Nurhak Erbas
Mechanical & Aerospace Engineering Theses & Dissertations
Effectiveness of an actuator is investigated for thermal-flow control in microchannels. First, simulations of a single actuator in a quiescent external medium are performed in order to study the parameters characterizing the synthetic jet flow from the actuator. For this purpose, a simplified, two-dimensional configuration is considered. The membrane motion is modeled in a realistic manner as a moving boundary in order to accurately compute the flow inside the actuator cavity. The geometric and actuation parameters of the actuator are investigated to define the effectiveness of the jet flow. The study is done initially at macro scales. Then, the flow …