Conferences, Lectures, & Seminars
Events for October
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Turbidity Currents Interacting with the Seafloor
Wed, Oct 14, 2009 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Eckart Meiburg Professor Department of Mechanical Engineering University of California at Santa BarbaraSanta Barbara, CA 93106 We will present high-resolution, Navier-Stokes based simulations and linear stability investigations of turbidity currents, and their two- way interaction with the seafloor. The turbidity currents we consider are driven by particles with negligible inertia that are much smaller than the smallest length scales of the buoyancy-induced fluid motion. For the mathematical description of the particulate phase an Eulerian approach is employed, with a transport equation for the particle-number density.
We will discuss some effects due to complex topography. Furthermore, we will analyze the linear stability problem of channel and sediment wave generation by turbidity currents. A novel linear instability mechanism is identified that can potentially create both of these topographical features. Its relation vis-a-vis the classical lee wave mechanism is discussed. In addition, results will be shown regarding the unsteady interaction of a gravity current with a submarine structure, such as a pipeline.
Location: Stauffer Lecture Hall, (SLH) Rm 100
Audiences: Everyone Is Invited
Contact: April Mundy
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Effect of Plasma Discharges on Spacecraft: An Experimental View
Wed, Oct 28, 2009 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Timothy P. Graves Electric Propulsion and Plasma Science SectionThe Aerospace Corporation2310 E. El Segundo Blvd.El Segundo, CA 90245-4609 Abstract:Successful satellite design and operation requires proper understanding of the many plasma phenomena associated with spaceflight. Various types of plasma discharges affect satellite components on-orbit, and in some cases, they can lead to critical failures in susceptible hardware. Some key examples of these phenomena are electrostatic discharge (ESD), plasma propulsion effects, and RF/microwave plasma discharges. The Aerospace Corporation's Electric Propulsion and Plasma Science Section continues to experimentally research these areas to improve current understanding and provide necessary data to avoid potential satellite failures. In this talk, the plasma physics and mitigation strategies associated with the aforementioned plasma discharges will be discussed. Additionally, the unique experimental capabilities and techniques developed in Aerospace laboratories will be described with specific emphasis on how the data are used to improve satellite design and operation. Recent experiments include laboratory ESD formation and measurement on solar panel coupons, NASA's Evolutionary Xenon Thruster (NEXT) plume measurements, satellite communication and plasma thruster electromagnetic interference, and the effect of surface contamination on multipactor discharge.
Location: Stauffer Science Lecture Hall (SLH), Rm 100
Audiences: Everyone Is Invited
Contact: April Mundy